Talk:XYY syndrome

Merge
When I did the merge from Xyy syndrome I found some questionable content.
 * Some studies show a higher concentraion of XYY males in prisons than in the general population, thus reflecting behavioral difficulties in children translating into criminal behavoir as adults.
 * There are conflicting studies on XYY and the effect on IQ. Some show that the IQ of XYY males is 10 to 15 points lower than siblings, others show IQ not varying from population wide averages.
 * Children with XYY may benefit from regular demanding physical exercise and additional encouragement in developing language skills. This may reduce the likelihood and severity of any behaviorial problems.
 * The Turner Center For Information, Counselling, and Research has published a booklet on the XYY syndrome. This booklet can be ordered free of charge by request to the centre.

I will not put these statements on the main page, they seem out of date and maybe biased. If someone wants to move them to the main article, please locate recent sources from the medical literature to back it up. Thatcher131 02:28, 18 February 2006 (UTC)

Mistaken statistical reasoning
I'm not very happy with the section about a greater proportion of people with XXY being found in the prison population, and then inferring that XYY people are inherently aggressive.

I do not know if there are a greater proportion of XYY people in prison or not, but let me in any case illustrate by example this statistical mistake that's very easy to make.

Lets imagine there are twice as many red-haired men in prison compared with the proportion of red-haired men men in the population as a whole. Should this lead to a conclusion that red haired men in general are more aggressive, that red-hairedness probably indicates an aggressive personality?

No, because only 1% of red-haired men are in prison. 99% of red-haired men are perfectly law-abiding citizens. Thus using red-hairedness as a sign of aggression is incorrect for the 99% of red-haired men who lead blameless and responsible lives. Thus, red-hairdness is useless as a means of signaling an aggressive personality.

It is easy to make the mistake in statistical reasoning illustrated by the above. I do not know what the name of this bias or fallacy is, but could someone edit the article to refer to it please?

I am sensitive about this because, although as far as I know I am not XYY, I am unsually tall as a result of having tall parents, which some people seem to think is a result of being XYY, or may be just seen as being a sign in itself of aggression. From Goliath onwards, unusually tall people have always had a bad press. We are still invariably depicted in popular culture and the media as being aggressive. This is a great burden to bear through life, as many people (and institutions and organisations) are spontaneously unpleasant even though I've never seen them before in my life, So lets all try and avoid this kind of reasoning and make life a little more bearable for XYYs.


 * I'm not quite sure I agree with your logic. You're completely right that it's absurd to assume that any given person who has an increased risk factor for condition Q automatically possesses condition Q, but from that point on I disagree with you.  Look at it this way: the proportion of people who were abused as children is (say) twice as high in prison as outside.  Does that mean that being abused as a child makes you more likely to go to prison?  Well, yes it does--even if only 1% of abused children end up in prison, if 0.5% of non-abused children do as well, it doubles your chance of ending up in prison. Ckerr 06:59, 21 March 2007 (UTC)

Incidence
Changed incidence from 1 in 850 to 1 in 1,000 boys as given in References (Nielsen 1998, Allanson & Graham 2002, Milunsky 2004, Nussbaum et al. 2004, Beltz 2005, NLM Home Genetics Reference 2006).

The estimated incidence of 1 in 1,000 males given in most recent scientific journal articles and current medical genetics reference books is based on a pooled estimate from several studies--including the largest single study by Nielsen & Wohlert (Human Genetics 1991;87:81-3) that reported an incidence of 1 in 851 males.

Dr. Nielsen gives an estimated incidence of 1 in 1,000 males in his 1998 booklet [http://www.aaa.dk/TURNER/ENGELSK/XYY.HTM#freq XYY Males. An Orientation]rather than the incidence of 1 in 851 males from his own 1991 single study. Panda411 05:47, 29 May 2006 (UTC)

Article should specifically reject notion that XYY people are aggressive
I noticed that the following has been cut from the article: "There have been suggestions of elevated frequency of XYY genotype in inmates and delinquents, yet the vast majority of people with XYY syndrome are neither offenders or delinquents. A common myth is that the Y Chromosome (male sex chromosome) adds to the aggression and antisocial behavior of people who have this syndrome. No clear evidence exists of it leading to aggression."

I can see this cut has good intentions, but the problem is, if someone who already thinks that XYY people are aggressive reads the article, then the current form of the article will do nothing to rebut this false/mistaken impression. Perhaps the paragraph above, or something similar, could be included under a heading something like "Outdated beliefs about XYY". Then people will have their mistaken beliefs corrected.


 * I remember hearing something about how prison inmates did have a higher incidence of XYY. it was on a TV documentary a while ago, but i forget what the show was. I know thats not a very concrete argument, but unless there is research to sugest that it does not increase violence, we shouldn't say it doesnt. Also, how much research is there about incidence of XYY in people nominated for "nice guy of the year"? Kaldosh 07:57, 10 June 2006 (UTC)
 * The comment above is an example of what I said above. You should read the comment headed Mistaken Statistical Reasoning. You are making a common mistake in reasoning which even highly educated professional people make. You are making a mistake in conditional probability by confusing p(XYY|prison_inmate) with p(prison_inmate|XYY). A more extreme example of this would be like saying that because most people in Nunnerys are female, therefore most females are Nuns. Your later comments seem just like common prejudice.


 * Another example that springs to mind is the Demonisation or Demonization (?) of young men in the UK that was in the news a while ago. Because there are a lot of young men in prison or youth custody (and receiving Asbos), some politicians tried to demonise them, but this quickly fell out of favour when it was realised that it alienated their voting parents. The politicians were making (cynically or not), and encouraging other people to make, the mistake in reasoning that p(young_man|criminal) equals p(criminal|young_man).


 * See Prosecutor's fallacy - this is about the same fallacy in a courtroom setting. -- Avenue 23:45, 22 July 2006 (UTC)


 * What I had been told about this specific example, males with XYY in prison was based on a different statistical error. The number of men in the general population with XYY were under-estimated.  With an expected figure lower than actuality the incidence in the prison population was assumed to represent a disproportionate number.  After the incidence of XYY was checked in a general population study it was found to be the same level of incidence as the prison population.


 * So if 1:800 male prisonners are XYY and 1:800 males are XYY there is no correlation.


 * If this history is re-incorporated into the main article as a history it should be mentioned that the fear of 'Supermasculinity' was a projection of a link between masculine identity and violent behaviour by theorists. There should be a link to biodeterminism.

David Cheater 02:26, 12 August 2006 (UTC)


 * It would be good to have this noted in the main article, plus the comments below about the false speculation by scientists and journalists about 'supermales' in the 1960s.

I agree that there should be an account of how speculations by scientists and journalists about 'supermales' arose in the 1960s. But I think it should be in a separate Wikipedia article on the History of the XYY syndrome, to both clearly distinguish past misconceptions about XYY from current medical understanding and to avoid devoting most of an article about a genetic condition to an account of past misconceptions about it.

I moved the following unsourced, somewhat misleading and only partly correct statement from the article to this Talk page:


 * A prior report had incorrectly reported a link due to the number of men in the general population with XYY syndrome being underestimated and the incidence discovered in the prison population seeming disproportionate, but subsequent checking found there to be the same incidence in the general population as in the prison population.

In 1965, Jacobs et al reported (in the most widely-read scientific journal in the world) finding 7 XYY men (over 3%) in a survey of the mentally retarded wing of the only British special (security) hospital in Scotland, a much higher than expected percentage. The report underestimated the incidence of XYY men in the general population, assuming it to be 1 in 2,000 instead of 1 in 1,000, but the percentage was still much higher than expected, and a similar percentage of XYY patients was later found in the other three British special hospitals in England and in similar hospitals in France.

In 1981, Jacobs said that in retrospect she should not have entitled her original report "Aggressive behavior, mental sub-normality and the XYY male" because she and her colleagues had not examined the XYY patients or their behavior when they wrote their original report, and when they actually did examine the XYY patients and their behavior (and published their findings in follow-up reports in 1967 and 1968 in less widely-read journals), they found that their initial assumptions about the XYY patients and aggression were completely incorrect.

In 1968, Jacobs et al conducted the first (and only ever) comprehensive, nationwide chromosome survey of prisons and found that the proportion of XYY men in prison was exactly the same as the proportion of XYY men in the general population: 1 in 1,000. Panda411 21:36, 28 August 2006 (UTC)
 * That's very interesting. Do you have the full bibliographic references please, as I would like to quote them.
 * Here's a more recent article on the subject: --apers0n 12:37, 7 September 2006 (UTC)

Here are some references:
 * 1) Jacobs PA, Brunton M, Melville MM, Brittain RP, McClemont WF (1965). Aggressive behavior, mental sub-normality and the XYY male. Nature. Dec 25; 208(17):1351-2.
 * 2) *7 XYY patients (of 197) in mentally subnormal hospital wing (1 not mentally subnormal)
 * 3) Price WH, Strong JA, Whatmore PB, McClemont WF (1966). Criminal patients with XYY sex-chromosome complement. Lancet. Mar 12; 287(7437):565-6.
 * 4) *2 additional XYY patients (of 118) in mentally ill hospital wing (neither mentally ill, 1 mentally subnormal)
 * 5) Price WH, Whatmore PB (1967). Criminal behavior and the XYY male. Nature. Feb 25; 213(78):815.
 * 6) Price WH, Whatmore PB (1967). Behavior disorders and pattern of crime among XYY males identified at a maximum security hospital. Br Med J. Mar 4; 1(5539):533-6.
 * 7) *XYY patients less aggressive than XY patients; most XYY patients never convicted of a crime against a person
 * 8) Jacobs PA, Price WH, Brown WM, Brittain RP, Whatmore PB (1968). Chromosome studies on men in a maximum security hospital. Ann Hum Genet. May; 31(4):339-358 (no pubmed entry)
 * 9) *incl. 11-page appendix w/case histories of all 9 XYY patients
 * 10) Brown WM (1968). Males with an XYY sex chromosome complement. J Med Genet. Dec; 5(4):341-59.
 * 11) *first comprehensive XYY review article, includes results of following survey:
 * 12) Jacobs PA, Price WH, Richmond S, Ratcliff RA (1971). Chromosome surveys in penal institutions and approved schools. J Med Genet. Mar; 8(1):49-58.
 * 13) *first/only nationwide survey of prisons (in Scotland); incl. 4-page appendix w/case histories of 2 XYY men & 6 XYY boys
 * 14) Jacobs PA (1982). The William Allan Memorial Award address: human population cytogenetics: the first twenty-five years. Am J Hum Genet. Sep; 34(5):689-98.
 * 15) *address given Oct 1981: said in retrospect, 1965 article was mistitled—should not have assumed & implied a link between XYY and aggressive behavior

Daly RF, Harley JP (1980). Frequency of XYY males in Wisconsin state correctional institutions. Clin Genet. Aug; 18(2):116-22. Panda411 06:34, 9 September 2006 (UTC)
 * The Wisconsin chromosome survey over 5 years (1975-1979) of 2/3rds of the men in 2 maximum security prisons, 1 medium security prison, 1 maximum & medium security boys school, and 1 maximum security mental hospital, found 16 XYY males (0.5% overall, 5 times the XYY prevalance in the general male population). 9 XYY men were found in one prison, 3 XYY men were in found in a second prison, and only 1 XYY man in the third prison. 2 XYY boys were found in the boys school, and 1 XYY man was found in the maximum security mental hospital. The researchers said they had no explanation for the high concentration of XYY men in one prison, and that if it had not been included their results would have been entirely different. The study calculated the XYY frequency in juvenile offenders as 10 times that of the general population based on just 2 XYY boys, and calculated the XYY frequency in the mental hospital patients based on just 1 XYY patient. The article only provided information on the race, age and height of the XYY men and boys.

Moved following sentences from article to talk page:
 * A common myth is that the Y Chromosome (male sex chromosome) adds to the aggression and antisocial behavior of people who have this syndrome. No clear evidence exists of it leading to aggression.

As noted above, this is a common myth that first arose due to an assumption in the 1965 report by Jacobs et al. that was subsequently found to be incorrect.

The myth has been and still is perpetuated in some science and medicine textbooks and websites by writers outside the field of medical genetics and unfamiliar with most XYY research and the XYY information found in current medical genetics reference books. One way writers perpetuate the myth is by making qualified statements such as "no clear evidence exists of it leading to aggression" which incorrectly imply that only clear evidence is lacking.

In fact, the unqualified statement "aggression is not seen more frequently in 47,XYY males" is the consensus of medical genetics experts in sex chromosome abnormalities as reflected in the five current authoritative medical genetics references cited for the statement. Panda411 15:49, 27 September 2006 (UTC)


 * Also of potential interest:
 * Beckwith J, King J. "The XYY syndrome: a dangerous myth" New Scientist 1974; 64: 474-476.
 * ... made some pretty damning comments on some of the early research that "popularised" the subject. ErkDemon (talk) 23:30, 30 May 2009 (UTC)

Removed: Jacob's syndrome, Supermale syndrome, XYY-trisomy and 47,XYY aneuploidy
Removed reference to Jacob's syndrome. Removed reference to Supermale syndrome. Removed references to XYY-trisomy and 47,XYY aneuploidy.
 * This is not an accepted name for 47,XYY and is not found in any published scientific journal article, medical textbook or dictionary.
 * It only appears in Dr. Sylvia S. Mader's popular series of high school/introductory college biology textbooks and related course materials.
 * Patricia Jacobs and her colleagues in Edinburgh published the first reports of the other two sex chromosome trisomies (47,XXY and 47,XXX) in 1959 and the first report of a group of 47,XYY males in 1965, four years after Dr. Avery Sandberg and his colleagues in Buffalo published the first report of a 47,XYY man in 1961.
 * This is not an accepted name for 47,XYY and is only used to refer to an incorrect stereotype put forth in the 1960s by some scientists and journalists based on speculations that turned out to be false.
 * XYY is a sex chromosome trisomy and 47,XYY is an aneuploidy, but these phrases are redundant and are not used together as a phrase in the medical and scientific literature.
 * XYY-trisomy only appears as the title of an outdated and inaccurate 33-year-old (1974) New Encyclopaedia Britannica Micropaedia article which was last revised 22 years ago in 1985.

Panda411 (talk) 17:49, 19 June 2006 (UTC)


 * I think that perhaps it should be in the article that it's known as "supermale syndrome", even though it does not quite exists. "supermale" redirects to this article, and it's listed on "criminology topics". Perhaps should be a section about misconception with the history of that thing of the guy who was exceptionally violent, but turned out to be just a normal XY guy in the end. If that's true.--Extremophile 14:11, 23 October 2007 (UTC)

Removed inappropriate "Jacob's syndrome" again. This term is not used for XYY in any medical genetics reference textbook nor in any journal article indexed by PubMed. Panda411 (talk) 01:27, 19 October 2013 (UTC)

Citation style
I propose changing this article's citation style from Harvard referencing to Footnotes to improve its readability. Would there be any objections to this? Panda411 03:52, 29 August 2006 (UTC)
 * Great, remember to cross it out on the To Do list when completed, thanks. --apers0n 06:02, 29 August 2006 (UTC)

pop culture XYY and why it ain't so
The last paragraph of the Behavioral effects subsection had said:


 * Developmental delays and behavioral problems are also possible, but these characteristics vary widely among affected boys and men, are not unique to 47,XYY and are managed no differently than in 46,XY males. Aggression is not seen more frequently in 47,XYY males.

On 5 December 2006, this was edited and changed to say:


 * Developmental delays and behavioral problems are also possible, but these characteristics vary widely among affected boys and men, are not unique to 47,XYY and are managed no differently than in 46,XY males.


 * In popular culture, including the TV series The XYY Man and the movie Alien 3, XYY males have been depicted as aggressive and even criminal. However, this is not supported by medical studies.

With an edit summary "pop culture XYY and why it ain't so".

I have reverted this paragraph to its former wording and meaning because:


 * 1) The original sentence (supported by citations from 5 current authoritative medical references) definitively said "Aggression is not seen more frequently in 47,XYY males". The edit weakened and changed its meaning from the original cited references to merely say that (aggression in XYY males) "is not supported by medical studies".
 * 2) A short-lived (13-episode) summer-filler British TV series from 30 years ago (that has never since been available on video) and a bad sci-fi movie sequel from 12 years ago are too obscure to define popular culture.
 * 3) There was already a link in the See also section to the Genetics Influencing Aggression article with information about historical scientifically discredited assumptions about XYY (I restored the See also section which was deleted by a different editor on 10 December 2006).

Panda411 13:48, 14 December 2006 (UTC)

John Money
Removed the following statement that was based on very limited, biased, outdated research from over three decades ago:


 * Behaviour that has been reported as more common in 47,XYY individuals as compared with 46,XY is: irritability, hyperactivity, impulsiveness and emotional outbursts.

citing:
 * Money, John (2002). "Chapter 7: Behavioral Cytogentics" in A First Person History of Pediatric Psychoendocrinology. New York: Kluwer Academic/Plenum Publishers. ISBN 0-306-47369-0, pp. 77-82.
 * "The syndrome of 47,XYY is not restricted to the institutionalized. Noel and Revil (1974) found sixteen examples of it by karyotyping samples of blood from blood donors in the general population of Chambéry, France. In their survey, Noel and Revil found that their sixteen 47,XYY men had no criminal history, but as compared with 46,XY men they were more impulsive and irritable, less able to cope with hostility, more given to emotional outbursts and were more unpredictable at home and work."


 * citing:
 * Noel B, Revil D (1974). "Some personality perspectives of XYY individuals taken from the general population". J Sex Res 10(3):219-25.
 * A 1974 study by French researchers who assumed XYY men to be tall and aggressive, found that 7 of 16 XYY men (only 2 of whom had completed the 3rd year of secondary school) had a somewhat different psychological profile on Rorschach, TAT, and projective drawing tests compared to 28 XY control men in Chambéry, France.
 * "For four of seven XYY individuals, compared with none in the control group, the preferred leisure time activities were hunting and often judo. It could be hypothesized that these subjects find in these activities the possibility to sublimate their aggression."

Controversial sexologist John Money's autobiographical 2002 retrospective review is completely ignorant of any research on XYY (and other sex chromosome aneuploidies) in the last three decades--since his highly unethical and tragically unsuccessful experiment chemically castrating (with massive doses of Depo-Provera) XYY young men and boys who had antisocial (not sex-offending) behavior problems.[] Panda411 18:48, 3 January 2007 (UTC)

YY Syndrome
Is this possible? Or maybe even just a "Y" syndrome? Like maybe if the X chromosome falls apart into a Y? —Preceding unsigned comment added by 75.30.219.118 (talk • contribs)


 * No I think you need an X chromosome, and I'm not sure if an X could become a Y if the genes are removed 71.65.34.160 03:20, 12 April 2007 (UTC)


 * Impossible. While the male contributes either an X or Y sperm, Egg cells are only made from the woman's X chromosomes. Unless the female had a Y somewhere(Which she wouldn't, that would make her a man), the child would have to have at least one X. 98.232.14.59 (talk) 05:41, 11 November 2008 (UTC)


 * It actualy isn't impossible to conceive, however it is impossible to bring to term because it is embryonic lethal (that is to say it is non-viable.) It can occur by the fertilization of an empty ovum by two 23,Y sperm (or possibly, by the fertilization by one 46,YY produced by nondisjunction during meiosis). This may seem bizarre, but a similar process produces an obstetric malignancy, the hydatiform mole. A complete mole results from the fertilization an empty ovum by either two sperm 23,X or possibly a 46,XX sperm. 69.37.84.6 (talk) 14:21, 24 December 2008 (UTC)GMM


 * Not only nondisjunction, but also trisomic rescue, which results in uniparental disomy of the sex chromosomes from the father (i.e. the Y chromosomes). XYY might turn into YY by trisomic rescue (eliminating the maternally-derived X chromosome). Wait a minute, why are all the people posting in the section "YY syndrome" here on Talk:XYY syndrome using IP addresses? --121.7.203.206 (talk) 14:56, 23 May 2009 (UTC)


 * You guys all forgot to indent your discussions, so I fixed that. Well now I'm the first registered user here! Protactinium-231 (talk) 03:48, 25 December 2009 (UTC)


 * This discussion began over a decade ago, but hey, it's relevant information. Since this conversation, there actually has been a report of a living human with a 46,YY cell line (and a 45,Y one!). It's A Novel Sex Chromosome Mosaicism 45,X/45,Y/46,XY/46,YY/47,XYY Causing Ambiguous Genitalia (Khan, 2017) and describes a three-year-old boy with 7.5% of his cells lacking an X chromosome. The ambiguous genitalia is likely unrelated to the Y/YY lines, and rather an effect of 20% of his cells being 45,X. Sadly, the study includes no developmental information. Vaticidalprophet (talk) 16:20, 8 September 2018 (UTC)

Extra Y?
Sorry. Just wanted to come in again to say: where does the extra Y chromosome come from? --121.7.203.206 (talk) 15:00, 23 May 2009 (UTC)

Removed weasel worded cruft
Removed section starting with "some medical..." it is both weasel worded and inaccurate in regards to the content of the article. Drappel, please stop reverting or read the god damned talk page, some medical practitioners..." is weasel word crap, and the discussion of phentype is DIRECTLY contradicted in the following paragraph. I am not a vandal, but at this point you are. —Preceding unsigned comment added by 70.121.7.89 (talk)


 * Not weasel words. And it's properly cited from a legitimate source. Ward3001 03:48, 19 March 2007 (UTC)


 * Bullshit "some medical" is classic weasel word crap. I demand mediation. —The preceding unsigned comment was added by 70.121.7.89 (talk) 03:51, 19 March 2007 (UTC).


 * From medical geneticists Graham, Allanson & Gerritsen's chapter "Sex Chromosome Abnormalities" in the most authoritative and comprehensive medical genetics reference textbook: Rimoin, Connor, Pyeritz & Korf (eds.) Emery and Rimoin's Principles and Practice of Medical Genetics, 5th ed. (2007), on page 1047, the first three sentences of the "47,XYY Karyotype" section:
 * 47,XYY is present in approximately one in 1000 newborn boys. This sex chromosome aneuploidy is not characterized by distinct physical features and, because there does not appear to be a recognizable pattern of neurodevelopmental or behavioral characteristics, the use of the term syndrome may be be inappropriate. Males with an extra Y chromosome are phenotypically normal and most never come to medical attention.
 * Note also that the ICD-10 name for this condition (Q98.5) is: "Karyotype 47,XYY" not "XYY Syndrome".
 * Panda411 18:58, 21 March 2007 (UTC)

Revert help
I've used up my three reverts for today. Can someone revert this edit as it is the same thing that multiple editors keep on deleting? Mermaid from the Baltic Sea 04:10, 19 March 2007 (UTC)


 * It's done now, so nevermind anymore. Thanks for helping! Mermaid from the Baltic Sea 04:35, 19 March 2007 (UTC)

Questionable use of sources?
I'm not convinced by some of the sources used. Specifically, the reference for Daly and Harley (1980, PMID: 7438492) is used to support the contention that XYY is not correlated with increased rates of "aggressiveness", while that paper states that they found frequencies of 5-10 times the expected values in penal institutions! It seems to me that the paper directly contradicts the point which it is referenced being in support of.


 * Daly & Harley (August 1980) has never been cited in the Wikipedia article itself.
 * The five sources cited in the Wikipedia article for the sentence:
 * "Aggression is not seen more frequently in 47,XYY males."
 * are:
 * chapters on sex chromosome abnormalities (Graham et al. 2007, Milunsky 2004) in the latest editions of the most authoritative and comprehensive medical genetics reference textbooks,
 * sections on sex chromosome abnormalities in a leading introductory medical genetics textbook (Nussbaum et al. 2004) and an encyclopedia of genetic disorders (Beltz 2005),
 * an XYY information leaflet (Guy's Hospital 2001) by the Clinical Genetics Department (a UK regional genetics centre) at Guy's Hospital (an internationally renowned teaching hospital in London).


 * Daly & Harley (August 1980) was mentioned by another editor in a previous section of this Wikipedia article Talk page, and I commented on some of the limitations of its survey of Wisconsin prisons compared to the first and only nationwide survey of prisons (in Scotland) by Jacobs et al. (March 1971) . In contrast to the Scotland survey which provided case histories of each of the XYY men and boys it found, the Wisconsin survey provided only the race, age and height of the XYY men and boys it found, providing no information on "aggressiveness."


 * Panda411 19:05, 21 March 2007 (UTC)

Secondly, the fact sheet compares mean IQ between siblings with and without XYY to the standard deviation of IQ between siblings. They seem to use the fact that the two numbers are comparable to imply that the effect isn't significant. But instead all it means is that there is a fair degree of overlap between the two distributions, which is less reassuring--on average, a child with XYY will still have 10-15 fewer IQ points than a child without XYY, which is significant regardless of what the distribution is.


 * The XYY information leaflet (November 2001) by the Clinical Genetics Department (a UK regional genetics centre) at Guy's Hospital (an internationally renowned teaching hospital in London) does not say that IQs that are on average 10-15 points lower than siblings is not significant, it puts that average difference in the context of the average variation of IQ between siblings, which makes it impossible to predict the IQ of an individual XYY boy:


 * There is a wide range of abilities in boys with XYY, as there is with other children. The average intelligence (IQ) of boys with XYY is slightly lower than that of boys with normal chromosomes, and compared with their brothers and sisters their IQ is 10-15 points lower.
 * It is important to realise that this amount of variation often occurs naturally between children in the same family.
 * (bold emphasis in the original)


 * Panda411 19:05, 21 March 2007 (UTC)

Anyway, I don't know if the article is quite dubious enough to tag, but I do think it's an example of why things from Wikipedia should be taken with a grain of salt. Ckerr 07:24, 21 March 2007 (UTC)

Removed statements citing Wilson & Cooley (2000)
Removed two sentences added on 17 December 2006 citing Wilson & Cooley (2000):


 * Since the only clear physical characteristic is the stature, the condition usually is only detected during genetic analysis for another reason.


 * Possible complications include early clumsiness and fine motor problems, muscle weakness and incoordination.


 * Stature is not a "clear physical characteristic" of XYY that prompts genetic analysis.


 * While there have been reports of XYY males with early clumsiness, fine motor problems, muscle weakness or incoordination, these have not been shown to be characteristic of XYY males.

The first edition of: Wilson & Cooley (2000) Preventive management of children with congenital anomalies and syndromes ISBN 0-521-77673-2 has three paragraphs on page 170 about "47,XYY Syndrome." The information in the three paragraphs is very inaccurate and outdated, including the following sentence from the first paragraph:


 * The most striking complications are developmental and behavioral differences, including early clumsiness and fine motor problems, muscle weakness and incoordination, borderline mental disability (IQ 70 to 90) in 38 percent, impulsive behavior and temper tantrums (Gorlin, 1990, pp. 61-2; Jones, 1997, pp. 70-1).

The references cited by Wilson & Cooley (2000) for this sentence are: Gorlin, Cohen, Levin (1990) Syndromes of the Head and Neck, 3rd ed. ISBN 0-19-504518-1 and Jones (1997) Smith's recognizable patterns of human malformation ISBN 0-7216-6115-7, both of which contain very inaccurate and outdated information, citing from 38 years ago: (Daly et al., 1969) a case report of a tall 5 year old XYY boy referred for a neurological examination because of awkwardness and an obvious articulation problem, and (Daly, 1969)  a report on the same 5 year old XYY boy and 11 XYY men found in a chromosome survey of patients 6 feet or more tall in six Wisconsin hospitals for the mentally ill or mentally retarded.

The second edition of: Wilson & Cooley (2006) Preventive Management of Children with Genetic Conditions: Providing a Medical Home, 2nd ed. ISBN 0-521-61734-5 has two paragraphs about "47,XYY Syndrome" on pages 206-7 with the same very inaccurate and outdated information presented in a different format and omitting references for the sources of the information.

Panda411 22:03, 21 March 2007 (UTC)

Physical traits section
This section currently says that there are no physical features characteristic of the syndrome, which I understand to be correct and is consistent with the rest of the article; however, it also says that "Most often, the extra Y chromosome causes extreme physical features and medical problems."

I'd assume this is an error or vandalism that hasn't been noticed, but I don't know enough about the area to correct it, so thought I'd mention it here. Cheers. SamBC(talk) 10:41, 19 February 2008 (UTC)


 * Reverted 11 February 2008 vandalism by 207.163.18.80. Panda411 (talk) 15:07, 19 February 2008 (UTC)

Isn't this article contradicting itself?

 * Most often, the extra Y chromosome causes no unusual physical features or medical problems.

vs.
 * 47,XYY boys have an increased risk of learning difficulties (in up to 50%) and delayed speech and language skills.

OK, "up to 50%" isn't "most often", but it looks odd to me... Aeluwas (talk) 12:26, 3 May 2008 (UTC)


 * I suspect that the second point you highlight needs modifying, as the following sentence says 10%, and I don't know how that compares to the general population. Someone ought to look at those references and see if the sentence might want to be prepended with "some studies suggest" or "older studies suggest" or something. As it is, that whole (short) paragraph is hard to get any sort of meaning from. SamBC(talk) 12:31, 3 May 2008 (UTC)


 * Also, it seems as though no context is given for two different percentages- several citations support 50% but the CDC study suggested only 10%? Is the one study refuting the other studies? Were the statistical methods significantly different and therefore the results cannot be compared? As of right now, it's confusing and more information about the discrepancy in results is needed. —Preceding unsigned comment added by 208.0.17.93 (talk) 14:15, 7 October 2008 (UTC)

Wording issue?
The article says that some say that it shouldn't be considered a syndrome because "the phenotype is normal". While I understand what is meant (there are no detrimental physical effects), the article says (with a cited source) that XYYs average 7 centimeters taller than XYs -- this is definitely a significant difference. "Normal" is a loose word, and when I first read that section, I thought it meant XYY had no phenotypic effects. Perhaps it should say, instead of "the phenotype is normal", "the condition is not associated with illness". What do you think? Vultur (talk) 22:47, 27 August 2008 (UTC)

omg this is a crappy page!!!! —Preceding unsigned comment added by 64.140.245.242 (talk) 19:39, 17 December 2008 (UTC)

Differences in IQ
The previous version of the article included a statement along the lines of "Boys with 47,XYY typically have an IQ 10-15 points lower than their siblings, but this is comparable to the normal variation between siblings." This may be true, but is misleading: for example, lead poisoning rarely leads to IQ deficits of more than 10-15 points (instead more like 5), but no one would brush aside lead poisoning as "comparable to normal variation between siblings".

Put more formally, the original statement conflates standard deviation (what the typical spread between siblings is) with standard error (what the difference in means is). Boys who do not have 47,XYY typically have an IQ exactly equal to their siblings, so 10-15 points is a very significant difference.

I have tried to rephrase the passage to make it clear that the effect of 47,XYY on IQ is significant, while still emphasizing the fact that not all boys with the condition will have low IQ. I know there has been conflict over this passage in the past, so hopefully the current version resolves these difficulties. Ckerr (talk) 15:23, 29 December 2009 (UTC)


 * Reverted inaccurate rephrasing which misrepresented these cited sources:
 * Guy's Hospital Clinical Genetics Department (2001, 2005). The XYY Condition. Scottish Genetics Education Network (ScotGEN).
 * Bloom B, Dey AN (2006). Summary health statistics for U.S. children: National Health Interview Survey, 2004. Vital Health Stat (National Center for Health Statistics) 10 (227): 1–85..
 * Linden MG, Bender BG (2002). Fifty-one prenatally diagnosed children and adolescents with sex chromosome abnormalities. Am J Med Genet 110 (1): 11–18..
 * Added a source for: "an average difference of 12 IQ points" between siblings
 * The IQ difference between ordinary siblings averages 12 IQ points, whereas randomly paired members of the population differ on average by 17 points.
 * Scarr, Sandra; Deater-Deckard, Kirby (1997). "Family effects on individual differences in development." in Luthar, Suniya S. (ed.) Developmental psychopathology: perspectives on adjustment, risk, and disorder. Cambridge: Cambridge University Press. ISBN 0521477158, p. 119.
 * Panda411 (talk) 02:41, 30 December 2009 (UTC)

I don't see how my changes can be characterized as "inaccurate rephrasing" or "misrepresentation", since as far as I know every factual statement I made is directly supported by the cited references. The statement about "...50% have learning difficulties, compared to 10% in the whole population..." is factually identical to the old version, just rewritten in what I felt was a more interpretable form. I removed the quotation from the Guy's Hospital pamphlet because it is misleading, as my example above shows; just because some statement appears on some pamphlet somewhere does not mean it is necessarily appropriate for inclusion in Wikipedia. The Bloom and Dey report does not even mention XYY, so I am not sure how it could support either of our views, while my version quoted the Linden and Bender study almost verbatim.

I'll leave the article alone for the time being, but unless you are willing to either (i) modify the wording of the article, or (ii) address the points I've raised, I'll request arbitration for the article. Ckerr (talk) 02:56, 11 January 2010 (UTC)


 * 1) The sentence:"47,XYY boys have an increased risk of learning difficulties (in up to 50%) and delayed speech and language skills."is sourced to six medical genetics reference textbooks, a medical genetics journal article, a UK Regional Genetics Centre information leaflet, and a National Library of Medicine genetics website article, all about 47,XYY boys.

The sentence:"In comparison, a national survey of US children conducted in 2004 for the CDC found that 10% of all boys had a learning disability." is not about 47,XYY boys, but is about US children, and is sourced to the CDC report on the survey.

These sentences should not be combined to say:"Up to 50% of 47,XYY boys are affected by learning disabilities, compared to 10% for the full population, according to a national survey of US children conducted in 2004 for the CDC." and sourced to the CDC report that is not about 47,XYY boys and says:"Almost 5 million children 3–17 years of age (8%) had a learning disability; 10% of boys had a learning disability compared with 6% of girls." "all boys" is simpler and less ambiguous than "for the full population."

That IQ scores between siblings vary naturally by an average difference of 12 points is a mean difference —a measure of variability within a population—not a standard deviation, which is another measure of variability within a population.
 * 1) That average IQ scores of 47,XYY boys, 47, XXY boys, and 47,XXX girls in newborn screening studies were 10–15 points below their siblings without sex chromosome trisomies is a difference in means between populations—not a standard error.

The patient information leaflet written by Guy’s Hospital Clinical Genetics Service (a UK Regional Genetics Centre)—based on the work of Dr. Shirley G. Ratcliffe, the pediatrician and geneticist at the MRC Human Genetics Unit at Western General Hospital in Edinburgh, Scotland who led the largest of eight international newborn screening programs for sex chromosome abnormalities in the 1960s and 1970s—does not conflate a difference in means with a mean difference—nor say that either difference is not significant. It simply notes (and emphasizes in bold print) that they are similar in magnitude:"There is a wide range of abilities in boys with XYY, as there is with other children. The average intelligence (IQ) of boys with XYY is slightly lower than that of boys with normal chromosomes, and compared with their brothers and sisters their IQ is 10-15 points lower. It is important to realise that this amount of variation often occurs naturally between children in the same family. About half of XYY boys may need some extra help at school, but the majority still manage well at mainstream school."Boys who do not have 47,XYY do  not  typically have an IQ exactly equal to their siblings. The average difference in IQ between two siblings is 12 points.

If the IQ scores of two siblings differ through natural variation by an average 12 IQ points, the genetic composition and environment of the sibling with the lower IQ score could be considered to be "defective" in comparison to that of the sibling with higher IQ score to approximately the same degree that the presence of an extra X or Y chromosome might be expected to affect an individual.

Linden MG, Bender BG (June 1, 2002). Fifty-one prenatally diagnosed children and adolescents with sex chromosome abnormalities. Am J Med Genet 110 (1):11–18:"Results From Prenatally Diagnosed Children
 * 1) This is a more accurate and balanced summary:"The Denver Family Development Study led by Arthur Robinson found that in 14 prenatally diagnosed 47,XYY boys (from high socioeconomic status families), IQ scores available for 6 boys ranged from 100–147 with a mean of 120. For the 11 of 14 boys with siblings, in 9 instances their siblings were stronger academically, but in one case they were performing equal to and in another case superior to their brothers and sisters."than your:"For example, in a study of 11 boys with 47,XYY and their siblings, in 9 instances the boys' siblings were stronger academically, while one 47,XYY boy performed equally well as his siblings, and one performed better. However, the fact that boys with 47,XYY have lower IQ scores than their siblings on average does not mean that all 47,XYY boys have low IQ scores: a study of 14 prenatally diagnosed 47,XYY boys from high socioeconomic status families found one with an IQ score of 147."of:

47,XYY. Fourteen 47,XYY boys, ages 8–16 years, were available for follow-up (Table I). Eleven boys were described by parents as tall and thin, while the others were of average height and weight. All were in good physical health. Four had occasional problems with asthma, and one had intention tremor of the hands.

Nine of the boys were in grade school and five were in high school. Five of the boys had received extra assistance in school for academic difficulties. Two of these boys were diagnosed with learning disabilities, and both were attending schools specializing in education programs for the learning disabled. Three boys had a diagnosis of ADD, and three others were noted to be distractible. Despite these problems, school performance in this group has been above average overall. Twelve of the 14 boys received grades of A’s and B’s in most of their subjects, while two boys received C’s and D’s. Academically, the boys favored science, mathematics, and reading. Eleven of the boys were particularly strong in science. In mathematics, 11 boys were said to excel with 3 reported as having difficulty. Nine of the group cited reading as a strong subject for them, and five reported it as a weak subject. Two boys (ages 8 and 16 years) had excellent academic performance in all areas. IQ scores were available for six boys with a range of 100–147 and a mean of 120. Five others were said by parents to be above average, and three were average.

Sibling comparisons were made in 11 cases, as 3 were the single child in the family. In nine instances, the siblings were said to be academically stronger and to have higher achievement in school than the 47,XYY boys. One 47,XYY boy was at the same level as his siblings, and the other 47,XYY boy was reported to be doing better in school than brothers and sisters."in which  all  14 XYY boys had IQs which were average or above average.


 * 1) As an additional note, while some sources, such as:"Linden MG, Bender BG, Robinson A (June 1, 2002). Genetic counseling for sex chromosome abnormalities. Am J Med Genet 110 (1):3–10."say (based on newborn screening studies):"The associated developmental risks for mild delays in motor skills and speech/language skills and the risk for learning disabilities have been noted. While the SCA [sex chromosome abnormality] karyotypes all contain a risk for these developmental difficulties, it is not possible to determine which child will exhibit any or all of these concerns. IQ is generally in the normal range but averages 10–15 points below siblings, and it is a minority who have intellectual disabilities. Behavior is variable, but psychopathology is not associated with SCA. The overall prognosis for each individual is not possible to predict.

Table I. Characteristics of Sex Chromosome Abnormalities IQ 45,X: In normal range, mean is 10–15 points lower than siblings 47,XXX: In normal range, mean is 10–15 points lower than siblings 47,XXY: In normal range, mean is 10–15 points lower than siblings 47,XYY: In normal range, mean is 10–15 points lower than siblings"not distinguishing differences in IQ between the four most common sex chromosome abnormalities. Other sources note that IQ scores are lowest in 47,XXX and highest in 47,XYY (47,XXX < 47,XXY < 45,X < 47,XYY). The number of 47,XYY boys in the newborn screening studies was roughly half that of the other SCA's because most of the eight newborn screening programs in the 1960s did not perform karyotyping of all newborns—but only on those found on buccal smear screening to have an abnormal number of Barr bodies (reflecting an abnormal number of X chromosomes) and did not screen for abnormal numbers of Y chromosomes until the 1970s. The reported effect of 47,XYY on IQ should therefore be interpreted being as a very rough estimate.
 * Panda411 (talk) 22:41, 13 January 2010 (UTC)

Likelyhood of male offspring
Looking at the way sperm is produced by cell division, normally making one daughter- (X) and one son-making-sperm (Y) from a fathers XY-cells, this leads me to the assumtion that there is an increased likelyhood for a XYY-man to have sons instead of daughters. My thinking that there are two possibilities of sperm to be produced: X and YY or XY and Y, creating (with normal one-X mother's eggs): XX, XYY, XXY and XY -children respectively. Two of them having 47 chromosome, but have the same chances to survive and being born (I haven't heard the opposite yet). That makes the chances for a boy 3:1. Apart from that the likelyhood to have a child with Klinefelter's syndrome (47,XXY) is 25%. Correct? Thoughts?

It should be easy to determine the percentage of sons of 47,XYY-males if one has a file of these individuals, so maybe a scientist working on this topic has already done a survey?

Thinking about it, is it possible that 47,XYY-males are the reason for overall more males than females being born? Note that in the case of 46,XY-father and 47,XXX-mother, (according to my simple calculations) the eggs are XX and X or X and XX and mixed with sperms X and Y the children are XXX, XX, XX, XXX, XXY, XY, XY, XXY = the same chance for XX, XY, XXX and XXY; 1:1 boys:girls--TeakHoken91.33.22.131 (talk) 23:02, 16 February 2010 (UTC)

The myth
I merged the "First case" and "The myth" sections into a new, expanded, chronologically organized "History" section that is subdivided—somewhat arbitrarily—into chronological subsections ("1960s", "1970s", "1980s and later"), incorporating in context many of the references from the former "The myth" section.

I removed mention of Robert A. Heinlein's 1970 science fiction novel I Will Fear No Evil. It is possible, given the publication year, that the one reference to a short-statured minor character as an "XYY" (changed to an "XYZ" in later printings), refers to the 47,XYY genetic condition, but since chromosomes are not mentioned, and no source says the reference is to the 47,XYY genetic condition, it doesn't warrant inclusion in this encyclopedia article.

I also removed mention of one episode (the season 2, episode 5, "By the Pricking of My Thumbs..." broadcast on Monday, January 18, 1971) of the BBC science fiction television series Doomwatch. This may have been the first fictional television series episode reference to the 47,XYY genetic condition, but it is not mentioned in any sources about the 47,XYY genetic condition. (It was added to The XYY Man article on May 15, 2007—and added to this article the following day—by Oxfordshire, England vintage British television buff 81.178.15.180.) In contrast, for example: Panda411 (talk) 23:43, 16 April 2010 (UTC)
 * Kenneth Royce's 1970 spy novel The XYY Man is mentioned in:
 * Reed Pyeritz, et al. (1977). "The XYY male: the making of a myth" (pp. 86–100) in Biology as a social weapon. ISBN 0808745344.
 * Jeremy Green (1985). "Media sensationalism and science: the case of the criminal chromosome" (pp. 139–161) in Expository science: Forms and functions of popularisation. ISBN 9027718318.
 * Jon Beckwith (2002). "The myth of the criminal chromosome" (pp. 116–134) in Making genes, making waves: a social activist in science. ISBN 0674009282.
 * Dario Argento's 1971 Italian-dubbed-into-English horror film The Cat o' Nine Tails is mentioned in:
 * Jeremy Green (1985). "Media sensationalism and science: the case of the criminal chromosome" (pp. 139–161) in Expository science: Forms and functions of popularisation. ISBN 9027718318.
 * Jon Beckwith (2002). "The myth of the criminal chromosome" (pp. 116–134) in Making genes, making waves: a social activist in science. ISBN 0674009282.
 * David Fincher's 1992 horror film Alien³ is discussed in the opening of:
 * Jon Beckwith (2002). "The myth of the criminal chromosome" (pp. 116–134) in Making genes, making waves: a social activist in science. ISBN 0674009282.


 * I think your very impressive work has made some great improvements to the article. However, I think a few things need attention.
 * It would make more sense to me to have the "first case" information and the very interesting last paragraph (on possible etiology of symptoms) with the medical information in the rest of the article instead of under "history".
 * I can't imagine the objection to mentioning the Doomwatch episode based on a source about TV science fiction. Is there some policy that the primary topic of a source must be that of the article?  If so, why?  And should the articles primarily on Richard Speck and Michael Court Brown be removed on the same grounds?  I really liked mentioning Doomwatch because the episode was against the prejudice, unlike the other culture examples, helping to show that pop views of XYY weren't monolithic.  (Full disclosure: I added that citation&mdash;a previous version had been removed&mdash;and I added the next two things I'm going to mention.)
 * I also really liked the "supermale" quote, as that was part of the myth and the quote explained it nicely.
 * I also liked having the argument for continuing the Boston study in the article, instead of just mentioned in a note with a link to a subscription-only article, for balance with the point of view that the study should stop.
 * The Nora and Fraser quotation doesn't look like a good example of misinformation to me.
 * I don't see the need for the Hubin review of The XYY Man. The Kneeland review, on the other hand, strikes me as a wonderful find.
 * I thought the Heinlein quotation improved the article a little. Looking at it in isolation, I see no reasonable doubt that it's about chromosomes, and later in the book, the hero(ine) says, "I'm not even a mixed-up XXY or an XYY.  This body is a normal female XX."  However, the improvement may not be enough to justify the use of a primary source without a secondary source. &mdash;JerryFriedman  (Talk) 03:47, 17 April 2010 (UTC)

In response to your comments, I have revised the article revised the article to: these are not worth mentioning in a encyclopedia article about the 47,XYY genetic condition: I'm not even a mixed up XXY or XYY. This body is normal female XX." Panda411 (talk) 00:02, 22 April 2010 (UTC)
 * add SHOX excess as a postulated cause of increased stature in 47,XYY (and 47,XXX, 47,XXY, 48,XXYY, etc.) to the "Physical traits" section
 * add GTPBP6 excess correlation with decreased verbal IQ in Klinefelter's syndrome (47,XXY) to a "Behavioral characteristics" section footnote for decreased IQ in Klinefelter's syndrome (47,XXY)
 * leave the 1961 first case of 47,XYY reported by Sandberg, et al. in the "1960s" subsection of the "History" section
 * readd mention of the 1971 Doomwatch episode, add mention of a 1993 Law & Order episode, add mention of a 2007 CSI: Miami episode
 * the objection to mentioning the 1971 Doomwatch episode (or the 1993 Law & Order episode, or the 2007 CSI: Miami episode) was that no source about 47,XYY mentions it—in contrast, many sources about 47,XYY mention Richard Speck or Michael Court Brown
 * add excerpts from Mary Telfer's November–December 1968 Think magazine article "Are some criminals born that way?" article to the citation footnote for that article—to put her use of the term "supermale" (and role in creating the XYY myth) in context
 * the quote from the poor quality August 1973 American Psychologist review article "Human aggression and the extra Y chromosome. Fact or fantasy?" by geriatric psychiatrist Lissy Jarvick, et al. is an example of the persistence (five years later) of Telfer's simplistic notion of:
 * a 47,XXY Klinefelter male "erring in the direction of femaleness"
 * a 47,XYY "supermale" "erring in the other direction" [of maleness]
 * regarding the 1970–1974 screening of non-private-ward newborn boys at Boston Hospital for Women for 47,XXY and 47,XYY:
 * the arguments that screening should continue were:
 * the arguments of the opponents of screening were unconvincing
 * that philosopher Daniel Callahan said Harvard Medical School bacterial physiology professor Bernard Davis was "appalled at the demise" (a few months ahead of schedule) of newborn screening at Boston Hospital for Women doesn't seem notable
 * child psychiatrist Stanley Walzer's prospective longitudinal follow-up study (of thirteen 47,XXY boys, eleven 47,XYY boys, and nine 46,XY control boys) did not end in 1974—it continued for another 15 years after the end (a few months earlier than originally planned) of newborn screening at Boston Hospital for Women
 * remove the Nora and Fraser (1974) Medical genetics: principles and practice textbook citation and quote
 * remove the Allen J. Hubin (October 4, 1970) book review of The XYY Man in The New York Times Book Review citation and quote
 * regarding Robert A. Heinlein's (1970) science fiction novel I Will Fear No Evil,
 * a passing reference to a "mousy, fatherly little man" minor character:
 * "But Charlie—the one riding Shotgun—is mean. An XYY. Committed his first murder at eleven. He—" or:
 * "But Charlie—the one riding Shotgun—is mean. An XYZ. Committed his first murder at eleven. He—"
 * a comment by the main character (with a man's brain transplanted into a woman's body) that:
 * "I'm not the ordinary sex change of a homo who gets surgery and hormone shots to tailor his body into fake female.

Context...
I removed the line about the 'context' re: IQ differences from the general population. Earlier in the paragraph a study is quoted as showing a lower IQ in comparison to siblings; removed quote cited a difference in IQ for a general populace sample. Since the two statistics are not directly correlative (one shows a trend, whilst the other shows a simple average, with no 'direction') I believe this to be a fallacy in logic (there's surely a term for this, mathematically, though I know it not). I am certainly open to discussion, here, but would request that the logic/mathematics, applied as the cut piece is worded, should trump any 'emotional' argument. I have no axe to grind with the parent article. —Preceding unsigned comment added by Regnad kcin75 (talk • contribs) 09:37, 5 August 2010 (UTC)

H. Bentley Glass
is mentioned in the article. Was he in favor of forced abortions or afraid of a future with such laws? Talk:H. Bentley Glass --80.187.97.4 (talk) 03:46, 28 May 2014 (UTC)


 * Glass preferred a voluntary eugenics program (perhaps augmented by tax penalties or fines like those of China's one-child policy) and hoped a forced abortion regimen "under a Nazi type of dictatorship" would not be necessary. Panda411 (talk) 01:03, 30 May 2014 (UTC)

Information from Danish studies - why I've included it here
An awful lot of recent ideas and information regarding XYY seem to be pointing in the direction of XYY being clinically insignificant, i.e. with no clear phenotype other than height differences and a possible propensity to learning disorders.

However I am aware that parents with XYY boys don't always see it that way - a quick look on the Unique page (charity for chromosome disorders in the UK) for XYY would appear to confirm this:

http://www.rarechromo.org/information/Chromosome_Y/XYY%20FTNW.pdf

My personal conversations with a clinical geneticist (in 2012) confirm the issues reported by Unique. So, it may actually be that XYY is as significant as originally thought, or at the very least, the picture is not as clear as we thought.

In line with that, I've included the main findings from two very recent studies from Denmark that support the view that XYY may be something that cannot be easily dismissed.

There's more that can be added to this XYY article along these lines. The Unique leaflet I've linked to here possibly represents useful evidence that all is not well with some XYY individuals, plus I have seen data showing an incidence of autism spectrum disorders of around 36% of XYY boys. Something is not right here, IMHO studies dismissing XYY may not be the whole story.

I suspect that as more data emerges from Denmark and a greater variety of studies emerge, this page could change quite significantly.

However, I am aware that both studies are relatively unknown and principally authored by the same individual, so I do not intend to directly contradict or remove the earlier findings reported on this page. I do not think the evidence is quite there yet. More information is required. — Preceding unsigned comment added by Prichardson (talk • contribs) 12:51, 10 December 2014 (UTC)


 * Per WP:MEDPRI, individual primary sources should not be cited or juxtaposed so as to "debunk", contradict, or counter the conclusions of reliable secondary sources.
 * I removed the following inaccurate, misleading section citing two recent biased primary source articles used to contradict the conclusions of the current medical genetics reference textbook WP:MEDRS secondary sources upon which this Wikipedia article is based:
 * • 12:36, 10 December 2014 Prichardson (talk | contribs) (new information from 2 recent studies in Denmark)"Recent Evidence from Denmark Denmark has been keeping a DNA database (Danish Newborn Screening Biobank at Statens Serum Institut) of all individuals born in the country since 1982.Danish Neonatal Screening Biobank This gives Denmark a specific capability to recognize individuals with XYY chromosomes throughout their population and compare to control groups who definitely do not have 47, XYY.  As a result of this, studies have been completed that show a different picture to older studies relying on individuals spotted through chance alone.  A 2009 study of 208 persons on record with XYY (36 deceased) found a decreased life span from 77.9 years in the controls to 67.5 years for XYY.  The study noted that the effect was 'even more than the expected loss of median lifespan in heavy smokers compared to non-smokers in Denmark'.  The areas of significantly increased mortality were found to be related to: cancer, neurological, and pulmonary diseases and trauma.Stochholm K, et al. (May 29, 2010). ' Diagnosis and mortality in 47,XYY persons: a registry study '. Orphanet J Rare Dis  Another study in 2011 (examining both XYY and Klinefelter's syndrome or KS), again using the Danish data, draws similar conclusions to the 1960s findings on XYY and criminality.  Noting that: 'diagnosed men with a sex chromosome trisomy in Denmark identified a significantly increased number of convictions, excluding traffic offenses, both in persons with KS and 47,XYY'.Stochholm K, et al. (Feb 22, 2012). ' Criminality in men with Klinefelter's syndrome and XYY syndrome: a cohort study '. BMJ Open"
 * Denmark has not been keeping a DNA database of all individuals born in the country.
 * The Danish Cytogenetic Central Register of Danish patients diagnosed with cytogenetic anomalies ≠ The Danish Neonatal Screening Biobank (NSB) of heel prick blood samples dried on filter paper (so-called PKU or Guthrie cards to screen for a variety of congenital diseases of metabolism) from all children born in Denmark since 1982 (and neither are DNA databases).
 * Denmark does not have the capability to recognize individuals with 47,XYY throughout the population.
 * The two biased studies you added are of the 15% of 47,XYY individuals diagnosed (at a median age of 20) because they had some physical problem, learning difficulty, or behavioral problem severe enough to prompt cytogenetic testing, along with a few found through prenatal cytogenetic testing for Down syndrome.
 * 85% of 47,XYY individuals in Denmark are not diagnosed.
 * The biased 2012 study of the 15% of Danish 47,XYY individuals who have been diagnosed found them to be different in socioeconomic status (marriage/cohabitation, achievement of a bachelor degree or higher, fatherhood, retirement) from a control group matched only on age. When results were adjusted for these socioeconomic status differences, significant differences for criminal conviction rates versus the control group essentially disappeared. The study provides no information whatsoever on the 85% of Danish 47,XYY individuals who have not been diagnosed.
 * The biased 2012 study of the 15% of Danish 47,XYY individuals who have been diagnosed does not draw "similar conclusions to the 1960s findings on XYY and criminality." It says: "The increased risk of convictions may be partly or fully explained by the poor socioeconomic conditions related to the chromosome aberrations."
 * The "Unique" support group XYY leaflet of anecdotal experiences from and for "a minority of families with a son with XYY chromosomes who encounter difficulties that test their parenting skills" is not a good source this encyclopedia article.
 * Panda411 (talk) 18:42, 10 December 2014 (UTC)

Assessment comment
Substituted at 10:57, 30 April 2016 (UTC)

External links modified
Hello fellow Wikipedians,

I have just modified 1 one external link on XYY syndrome. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added archive http://web.archive.org/web/20090614103635/http://www.cafamily.org.uk:80/Direct/x15.html to http://www.cafamily.org.uk/Direct/x15.html

When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at ).

Cheers.— InternetArchiveBot  (Report bug) 16:12, 16 July 2016 (UTC)