User:Snicks2/FG syndrome

FG syndrome (FGS) is a rare genetic syndrome caused by one or more recessive genes located on the X chromosome and causing physical anomalies and developmental delays. First reported by American geneticists John M. Opitz and Elisabeth G. Kaveggia in 1974, its major clinical features include intellectual disability, hyperactivity, hypotonia (low muscle tone), and a characteristic facial appearance including macrocephaly (an abnormally large head)

Presentation
FG syndrome's major clinical features include intellectual disability, usually severe; hyperactive behavior, often with an outgoing personality; severe constipation, with or without structural anomalies in the anus such as imperforate anus; macrocephaly; severe hypotonia; a characteristic facial appearance due to hypotonia, giving a droopy, "open-mouthed" expression, a thin upper lip, a full or pouting lower lip; and partial or complete loss of the corpus callosum. About a third of reported cases of individuals with FG syndrome die in infancy, usually due to respiratory infection; premature death is rare after infancy.

Developmental effects
Associated with agenesis (absence) of the corpus callosum, intellectual disabilities are common among individuals with FG syndrome. Motor ability is also impaired as a result of having FG syndrome and its effects on the development of neurons. During infancy, problems arise in the gastrointestinal and gastroesophageal systems of the body. The most common gastrointestinal problems include constipation from imperforated anuses and gastroesophageal reflux. Cardiopulmonary defects also contribute to roughly 60% of premature deaths in infants with FG syndrome. Of all of the congenital heart defects septal defects are the most common. After infancy, long term survival has been recorded to individuals surviving beyond the age of 50.

Diagnosis
There is no established clinical diagnostic criteria for FG syndrome. A healthcare professional might consider the following clinical features in an individual as indicative for further evaluation:


 * Neurodevelopmental delays
 * A family history consistent with X-linked inheritance
 * Characteristic facial features
 * Absolute or relative macrocephaly
 * Dolichocephaly
 * Frontal hair upsweep
 * Tall forehead
 * Downslanted palpebral fissures
 * Widely spaced eyes
 * Fullness of the upper eyelids
 * Small, simple ears (≤10th percentile)
 * Open mouth
 * Long narrow face
 * Broad thumbs and halluces
 * Congenital anomaly (corpus callosum, anal, cardiac, skeletal)
 * Hypotonia, constipation, or feeding problems
 * Characteristic behavior (affable and eager to please)

Treatment
Treatment for FG Syndrome is individualized to each person. It generally involves a team of specialist to manage the symptoms.

Support and resources

 * Unique: Understanding Rare Chromosome and Gene Disorders, https://www.rarechromo.org/
 * MED12 Related Disorders
 * National Organization of Rare Disorders, https://rarediseases.org/nordpod/
 * FG Syndrome Type 1
 * GARD: Genetic and Rare Disease Information Center, https://rarediseases.info.nih.gov/
 * FG Syndrome

History
Kim Peek (1951–2009) probably had FG syndrome.

The name of the syndrome comes from the initials of the surnames of two sisters, who had five sons with the syndrome. The first study of the syndrome, published in 1974, established that it was linked to inheritance of the X chromosome.

A 2008 study concluded that Kim Peek, who was the basis for Dustin Hoffman's character Raymond Babbitt in the movie Rain Man, probably had FG syndrome rather than autism.

FG syndrome was named after the first letters of the surnames of the first patients noted with the disease.