Talk:Tetrahydrobiopterin deficiency

Untitled
Some text in this article was originally taken from http://ghr.nlm.nih.gov/condition=tetrahydrobiopterindeficiency (public domain)

Name?
I was going to add a full diseasedisorder infobox to this article, but I can't work out exactly which variety of phenylketonuria this is. frex OMIM has four entries, none of which match exactly. I'll add a minimal box with [probably correct] icd codes and see what happens. Claus Diff 09:06, 14 September 2006 (UTC)

PKU is not the primary issue! Problems occur long before then
"Tetrahydrobiopterin deficiency (THBD, BH4D), also called THB or BH4 deficiency, is a rare metabolic disorder that increases the blood levels of phenylalanine." - well yes, in much the same way that not having enough brick layers increases the construction site levels of bricks. Or, just don't order the bricks (reduce L-Phenylalanine intake, such as they did until 2007). As I mentioned in the main BH4 talk page though, clinical issues will occur long before toxic levels of L-Phenylalanine. 99% of PKU isn't even caused by BH4 deficiency.

This continues on - "High levels of phenylalanine are present from infancy in people with untreated tetrahydrobiopterin (THB, BH4) deficiency." - etc. One can have low levels of BH4, but not so low as to have high/toxic levels of L-Phenylalanine, and yet still (due to the real purpose of BH4) not have enough of the neurotransmitters synthesized by the aminos BH4 is involved with. I'd like to think I'm not severely mentally retarded - having made it to 37 before being diagnosed with DRD - yet I still have had a lifetime of clinical issues resultant from my BH4 deficiency.

recessive/dominant genetic inheritance
"Mutations in the GCH1, PCBD1, PTS and QDPR genes cause THB deficiency" is later followed with "This condition is inherited in an autosomal recessive pattern" - except, the very first one listed (GCH1) is a dominant inherited trait, not recessive.

article necessity?
There are various issues in the article, but in the end the fact that the Tetrahydrobiopterin article itself is relatively short seems to suggest maybe BH4 deficiency should just be better described in the main article instead? Brianlamere (talk) 04:39, 9 September 2010 (UTC)

REFERENCES FOR THE MTHFR What references are there for this phrase "Additionally, mutations of the MTHFR gene (A1298C variant) can interfere with the recycling of BH4 and lead to less severe, but still clinifically significant, deficiencies of BH4."??? No trace about this on the web neither any study. Exept for the controversial theories of the naturopath Amy Yasko and others like her there seems not to be any scientific evidence for that. — Preceding unsigned comment added by Nessuno999 (talk • contribs) 22:59, 25 October 2013 (UTC)

Intersection with dopa-responsive dystonia
This 2021 review of dopa-responsive dystonia lists 6 conditions which almost completely overlap with the list of 6 conditions comprising tetrahydrobiopterin deficiency listed in this consensus guideline. Looks like BH4 deficiency and DOPA-responsive dystonia are two ways to look at processes which are heavily intertwined. I gradually created in the Russian Wikipedia the articles for the conditions listed in the review on BH4 deficiency, and now discovered that the same conditions are covered in a review on dopa-responsive dystonia. So I guess I'll be mentioning both umbrella notions in the individual articles, like this: this condition belongs to the BH4 deficiencies and to the dopa-responsive dystonias. --CopperKettle (talk) 01:14, 19 June 2022 (UTC)