Thumb duplication and contralateral thumb hypoplasia in infant of mother with diabetes

Uncontrolled maternal diabetes frequently results in congenital anomalies. This report describes an infant of a mother with diabetes born with thumb hypoplasia and contralateral thumb duplication without other associated anomalies. Maternal diabetes should be part of the etiologic differential diagnosis of thumb anomalies. The concomitant occurrence of thumb duplication and hypoplasia, apparently as a result of the same systemic insult, suggests a close relationship between hypoplasia and duplication.