| Edwards syndrome | |
|---|---|
| Other names | Trisomy 18 (T18),[1] chromosome 18 duplication,[2] trisomy E syndrome[3] |
 | |
| Chromosome 18 | |
| Specialty | Medical genetics, pediatrics |
| Symptoms | Small head, small jaw, clenched fists with overlapping fingers, severe intellectual disability[3] |
| Complications | Heart defects[3] |
| Usual onset | Present at birth[3] |
| Causes | Third copy of chromosome 18 (usually new mutation)[3] |
| Risk factors | Older mother[3] |
| Diagnostic method | Ultrasound, amniocentesis[2] |
| Treatment | Supportive care[2] |
| Prognosis | 5–10% survive past a year old[3] |
| Frequency | 1 per 5,000 births[3] |
Edwards syndrome, also known as trisomy 18, is a genetic disorder caused by the presence of a third copy of all or part of chromosome 18.[3] Many parts of the body are affected.[3] Babies are often born small and have heart defects.[3] Other features include a small head, small jaw, clenched fists with overlapping fingers, and severe intellectual disability.[3]
Most cases of Edwards syndrome occur due to problems during the formation of the reproductive cells or during early development.[3] The rate of disease increases with the mother's age.[3] Rarely, cases may be inherited from a person's parents.[3] Occasionally, not all cells have the extra chromosome, known as mosaic trisomy, and symptoms in these cases may be less severe.[3] An ultrasound during pregnancy can increase suspicion for the condition, which can be confirmed by amniocentesis.[2]
Treatment is supportive.[2] After having one child with the condition, the risk of having a second is typically around one percent.[2] It is the second-most common condition due to a third chromosome at birth, after Down syndrome.[4]
Edwards syndrome occurs in around 1 in 5,000 live births.[3] Some studies suggest that more babies that survive to birth are female.[2] Many of those affected die before birth.[3] Survival beyond a year of life is around 5–10%.[3] It is named after English geneticist John Hilton Edwards, who first described the syndrome in 1960.[5]
References
edit- ^ "Trisomy 18: description in brief". GOV.UK. Archived from the original on 4 June 2020. Retrieved 8 August 2020.
- ^ a b c d e f g "Trisomy 18". Orphanet. May 2008. Archived from the original on 3 October 2016. Retrieved 1 October 2016.
- ^ a b c d e f g h i j k l m n o p q r s "trisomy 18". GHR. March 2012. Archived from the original on 2 October 2016. Retrieved 1 October 2016.
- ^ Jorde, Lynn B.; Carey, John C.; Bamshad, Michael J. (2009). Medical Genetics (4 ed.). Elsevier Health Sciences. p. 109. ISBN 978-0323075763. Archived from the original on 2016-10-02.
- ^ "Edwards syndrome (John Hilton Edwards)". WhoNamedIt.com. Archived from the original on 2008-07-09. Retrieved 2008-07-24.