Hand-reduction malformations: genetic and syndromic analysis.

Sixty-one sequential patients initially referred because of hand-reduction abnormalities were retrospectively reviewed. Twenty distinct diagnoses were recognized. Particularly noteworthy was the number of instances in which standard classification schemes failed to explain fully the structural or syndromic characteristics in this group of patients. One-fourth (15 of 61) of the diagnoses were of disorders resulting from abnormalities of single genes; more than one-third (21 of 61) had multiple malformation syndromes. The importance of dysmorphologic and genetic investigation of individuals with congenital reduction malformations of the hands is evident from these data and from the cases presented.