Syndactyly
| Syndactyly | |
|---|---|
| Specialty | Medical genetics  |
Syndactyly (from Greek συν- = "together" plus δακτυλος = "finger") is a condition where two or more digits are fused together. It occurs normally in some mammals, such as the siamang but is an unusual condition in humans.
Classification
Syndactyly can be simple or complex.
- In simple syndactyly, adjacent fingers or toes are joined by soft tissue.
- In complex syndactyly, the bones of adjacent digits are fused. The kangaroo exhibits complex syndactyly.
Simple syndactyly can be full or partial, and is present at birth (congenital). In early human fetal development, webbing (syndactyly) of the toes and fingers is normal. At about 16 weeks of gestation, apoptosis takes place and an enzyme dissolves the tissue between the fingers and toes, and the webbing disappears. In some fetuses, this process does not occur completely between all fingers or toes and some residual webbing remains. The exact cause is not known. In cases, this condition appears to be hereditary.
Prognosis and treatment
In the case of human feet, syndactyly does not affect the function of the foot or toes and does not interfere with walking or swimming or any other activities. Although webbing of the fingers usually does not affect the function of the hand, it can impair function of the fingers.
Surgery may be performed to separate webbed fingers or toes. As with any surgery, there are risks of complications. This procedure involves local anesthesia with a sedative and can be done just with a local without the sedative for adults if desired. In addition to the incision between the fingers or toes, sometimes it is necessary to perform a skin graft, where some skin is removed from elsewhere on the body to graft into the newly exposed space between the fingers or toes.
In the case of webbed toes, surgical separation is a purely cosmetic operation with no medical benefits.
Genetics
Five types[1] of syndactyly have been identified in humans. The corresponding loci associated with these types and their common phenotypical expression are as follows:
- type I - 2q34-q36;[2] webbing occurs between middle and ring fingers and/or second and third toes.
- type II - 2q31;[3] also involves long and ring fingers, but has a sixth finger merged inbetween.
- type III - 6q21-q23; small finger is merged into the ring finger.
- type IV - 7q36;[4] involves all fingers and/or toes
- type V - 2q31-q32; similar to type I, but the metacarpals and metatarsels may also be fused.
See also
References
- ^ Flatt A (2005). "webbed fingers".
{{cite journal}}: Cite journal requires|journal=(help) - ^ Bosse K, Betz RC, Lee YA; et al. (2000). "Localization of a gene for syndactyly type 1 to chromosome 2q34-q36". Am. J. Hum. Genet. 67 (2): 492–7. doi:10.1086/303028. PMID 10877983.
{{cite journal}}: Explicit use of et al. in:|author=(help)CS1 maint: multiple names: authors list (link) - ^ Sarfarazi, Akarsu; et al. (1995). "Localization of the syndactyly type II (synpolydactyly) locus to 2q31 region and identification of tight linkage to HOXD8 intragenic marker" (PDF). Hum. Mol. Genet.
{{cite journal}}: Explicit use of et al. in:|author=(help) - ^ Sato D, Liang D, Wu L; et al. (2007). "A syndactyly type IV locus maps to 7q36". Journal of Human Genetics. 52 (6): 561–4. doi:10.1007/s10038-007-0150-5. PMID 17476456.
{{cite journal}}: Explicit use of et al. in:|author=(help)CS1 maint: multiple names: authors list (link)
 | This article about a disease, disorder, or medical condition is a stub. You can help Wikipedia by expanding it. |