Duplication of distal thumb phalanx in Shwachman-Diamond syndrome.

Shwachman-Diamond syndrome (SDS) comprises of exocrine pancreatic dysfunction, various degree of pancytopenia, and metaphyseal dysplasia. We report on a child with SDS and duplication of distal thumb phalanx. This combination has not been reported previously. We suggest that supernumerary thumb is likely a rare skeletal manifestation of SDS and that SDS should be considered in the differential diagnosis of patients with bone marrow failure and duplication of the thumb along with Blackfan-Diamond/Aase syndrome and Fanconi's anemia.