IS Case 556: Polydactyly of the hand
Imaging Sciences URMC 2010
Publication Date: 2010-09-25
History
Patient is a 6-month-old boy with polydactyly.
Findings
PA, oblique and lateral views of the left hand showed six digits with the abnormal digit being the second one in flexed position with one metacarpal and three phalanges and a bifid distal phalanx.
Diagnosis
Polydactyly of the hand
Discussion
Polydactyly is the most common congenital anomaly of the hand. The incidence of polydactyly is higher in African Americans compared to white people. It is more common in males than females. Polydactyly can occur as an isolated anomaly or can occur as a part of a syndrome. Isolated polydactyly has an autosomal dominant inheritance. About 15% of polydactyly cases are associated with other congenital anomalies. The common syndromes associated with polydactyly are Down syndrome and trisomy 13.
Temtamy and McKusick classified polydactyly into pre-axial, central and post-axial polydactyly. Pre-axial refers to duplication of the first digit, central refers to duplication of the second, third or fourth digits and post-axial refers to duplication of the fifth digit.
The treatment for polydactyly is usually surgery of the extra digit, more commonly done when the child is young for psychiatric and cosmetic reasons.
References
- Abel CG, McCarthy DM. Supernumerary digit. eMedicine, Jul 31, 2008. http://emedicine.medscape.com/article/1113584-overview
- Castilla EE, Lugarinho R, da Graça Dutra M, Salgado LJ. Associated anomalies in individuals with polydactyly. Am J Med Genet. 1998 Dec 28;80(5):459-65.
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