49, XXXXY syndrome
| 49, XXXXY syndrome | |
|---|---|
| Classification and external resources | |
| Specialty | Lua error in Module:Wikidata at line 446: attempt to index field 'wikibase' (a nil value). |
| ICD-9-CM | 758.81 |
| DiseasesDB | 32552 |
| Patient UK | 49, XXXXY syndrome |
49, XXXXY syndrome is an extremely rare aneuploidic sex chromosomal abnormality. It occurs in approximately 1 out of 85,000 to 100,000 males.[1][2]
Pathophysiology
As its name indicates, a person with the syndrome has one Y chromosome and four X chromosomes on the 23rd pair, thus having 49 chromosomes rather than the normal 46. As is common with aneuploidy disorders, 49, XXXXY syndrome is often accompanied by intellectual disability. It can be considered a form of Klinefelter syndrome,[3] or a variant of it.[1]
It is genetic, but not hereditary. This means that while the genes of the parents cause the syndrome, there is a small chance of more than one child having the syndrome. The probability of inheriting the disease is about 1%.[4]
The individuals with this syndrome are males, but 49, XXXXX also exists with similar characteristics as the female version.
Effects
Aneuploidy is often fatal, but in this case there is "X-inactivation" where the effect of the additional gene dosage due to the presence of extra X chromosomes is greatly reduced.[4]
Much like Down syndrome the mental effects of 49, XXXXY syndrome vary. Impaired speech and behavioral problems are typical.[5] Those with 49, XXXXY syndrome tend to exhibit infantile secondary sex characteristics with sterility in adulthood and have some skeletal anomalies. Skeletal anomalies include:
- Genu valgum
- Pes cavus
- Fifth finger clinodactyly
The effects also include:
- Cleft palate
- Club feet
- Respiratory conditions
- Short or/and broad neck
- Low birth weight
- Hyperextensible joints
- Short stature
- Narrow shoulders
- Coarse features in older age
- Hypertelorism
- Epicanthal folds
- Prognathism
- Gynecomastia (rare)
- Muscular hypotonia
- Hypoplastic genitalia
- Cryptorchidism
- Congenital heart defects
- A very round face in infancy[4]
See also
- Aneuploidy
- Turner syndrome
- Klinefelter syndrome
- 49, XXXXX, a similar syndrome that affects females
References
- ↑ 1.0 1.1 What is XXXXY syndrome? Retrieved March 26, 2008.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 4.0 4.1 4.2 Webspawner.com article on 49, XXXXY syndrome. Retrieved 26 March 2008.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
External links
- Lua error in package.lua at line 80: module 'strict' not found.
- 49 XXXXY at the National Organization of Rare Diseases
