Summary
Most limb reduction defects, when unilateral, are sporadic and of unknown etiology. Nevertheless, at least two families were described, suggesting an autosomal dominant transmission. In one family, adult female twins had unilateral terminal transverse defects affecting the left hand in one of them and the right hand in the other. The latter woman had one daughter with a unilateral terminal transverse defect affecting the left hand. In the other family it was a father-son transmission. Clinically, the hand anomaly is characterized by absence of the terminal portions of digits 2 to 5 with a hypoplastic thumb (adactylia). Tiny nail remnants may be present on the remaining digital stumps. Correspondent metacarpals are more or less severely reduced. In both families, different sides were affected in different generations. *Author: Dr E. Robert-Gnansia (August 2003)*.
