Brachydactyly type A2 (BDA2) is a congenital malformation characterized by shortening (hypoplasia or aplasia) of the middle phalanges of the index finger and, sometimes, of the little finger.Last update: May 2008
Only a few cases have been reported in the literature.
Characteristically, affected individuals have a triangular shaped middle phalanx of the index fingers and, in severely affected cases, the index finger is curved radially.
BDA2 can be caused by mutations in the BMPR1B gene on chromosome 4q or in the GDF5 gene on chromosome 20q11.
Autosomal dominant inheritance is suggested.