Congenital hand anomalies, and their association with other congenitalabnormalities

Congenital abnormalities of other parts occurring in patients with congenital abnormalities of the hand were studied. Hands and feet often showed similar anomalies, but there were some cases in which t e hands and feet had different Mnds of deformity. Anomalies of the internal organs were associated with anomalies of the thumb. Cleft lip and palate occurred in combination with syndactyly, split hand, preaxial polydaetyly and constriction ring syndrome. Combined anomalies may be the result of a genetic or environmental f ctor interfering with parts developing during the same critical period. The critical period and probable pathogenesis are discussed and the conclusion reached that mesenchymal necrosis, abnormal distribution of mesenchyme and tissue necrosis after mesenchymal condensation may be the pathological changes which lead to abnormal development of the hand