Fanconi Anemia Concurrent with an Unusual Thumb Polydactyly: A Case Report

Abstract

This case report presents a case of Fanconi's Anemia with an unusual thumb polydactyly in a 2-year-old boy. The extra thumb had no nail, nail bed and distal phalanx. The extra thumb had no active motion. The duplication of the thumb occurred at the carpometacarpal joint but its morphology did not match with any classification described for thumb polydactyly. Although his thumb polydactyly was apparent at birth, Fanconi's anemia was not suspected until during a routine pre-operative laboratory test (CBC) for the elective surgery of his thumb. An early diagnosis of FA is important and the hand surgeons may be the first to have the opportunity to suspect and diagnose the underlying life threatening disorder. This case report presented an opportunity to diagnosis a fatal disorder by a routine pre operative laboratory test. To the best of my knowledge, the phenotype of the thumb polydactyly of the current case has not yet reported.

Keywords: Congenital anomaly; Fanconi anemia; Thumb duplication; Thumb polydactyly.

Figure 1

Dorsal view of the right hand with thumb polydactyly. The nail is absent.

Figure 2

Palmar view of the right hand with thumb polydactyly. The thenar eminence is flat.

Figure 3

Antroposterior radiograph of the right hand with thumb polydactyly demonstrates that thumb polydactyly was at the level of carpometacarpal joint. In the most radial thumb the proximal bone represents the thumb metacarpal bone and the distal bone represents the proximal phalanx.