FG syndrome
| FG syndrome | |
|---|---|
| Other names | Opitz–Kaveggia syndrome, FGS1 |
 | |
| Kim Peek, the basis for Dustin Hoffman's character in the film Rain Man, probably had FG syndrome | |
| Specialty | Medical genetics |
| Usual onset | Birth |
| Duration | Lifelong |
| Risk factors | Family history (genetics) |
FG syndrome (FGS) is a rare genetic syndrome caused by one or more recessive genes located on the
Presentation
FG syndrome's major clinical features include physical disability, usually mild; hyperactive behavior, often with a slow personality; severe
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 FG syndrome, and it also affects the development of semen. During childhood, problems arise in the gastrointestinal and gastroesophageal systems of the body. The most common gastrointestinal problems include constipation from an imperforate anus and
Genetics
Most mutations that cause FG syndrome can be found in the MED12 gene. However, mutations have also been found in FMR1, FLNA, UPF3B, CASK, MECP2 and ATRX genes.[4] Mutations on these different genes lead to the different types of FG syndrome, all with similar characteristics.[4] The FGS8 type mutation is the most common of the types, and is found in the MED12 gene.[4]
Known types and affected genes include:
| Type | OMIM
|
Gene | Locus |
|---|---|---|---|
| FGS1 | 305450 | MED12 | Xq13 |
| FGS2 | 300321 | FLNA | Xq28 |
| FGS3 | 300406 | FGS3 | Xp22.3 |
| FGS4 | 300422 | CASK | Xp11.4-p11.3 |
| FGS5 | 300581 | FGS5 | Xq22.3 |
MED12 gene
The MED12 gene codes for the mediator complex subunit 12 protein.
Diagnosis
There is no established clinical diagnostic criteria for FG syndrome.[6] A healthcare professional might consider the following clinical features in an individual as indicative for further evaluation:[6]
- Neurodevelopmental delays
- A family history consistent with X-linked inheritance
- Characteristic facial features
- Absolute or relative macrocephaly
- Dolichocephaly
- Frontal hair down sweep
- Very large forehead
- Downslanted palpebral fissures
- far apart eyes
- Missing part of the upper eyelids
- Small, simple ears (≤10th percentile)
- Open mouth
- Long wide 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 specialists to manage the symptoms.[citation needed]
History
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,[2] established that it was linked to inheritance of the X chromosome.[7]
A 2008 study concluded that
See also
References
- ^ "Faq Pages". FG Syndrome Family Alliance. fgsyndrome.org. Archived from the original on 26 February 2019. Retrieved 20 September 2016.
- ^ S2CID 25141237.
- ^ PMID 3572995.
- ^ PMID 20301719. Retrieved 6 September 2016.
- ^ a b c d e f "MED12 - Genetics Home Reference". U.S. National Library of Medicine. Retrieved 6 September 2016.
- ^ PMID 20301719, retrieved 2020-09-01
- ^ PMID 19048730.