Fanconi's anaemia and unilateral thumb polydactyly--don't miss it.

Fanconi's anaemia (FA) is a rare, life threatening inherited syndrome. Patients usually present late in the first decade of life with aplastic anaemia or acute myeloid leukaemia. FA children are also at high risk of solid organ tumours, anogenital squamous cancers, and endocrinopathies. These patients can present with unilateral radial abnormalities including thumb duplication. Hand surgeons can help achieve early diagnosis and improved survival in this group by early referral for screening. In a retrospective study of 202 children with radial ray anomalies seen over a 20 year period seven children had FA. Of these seven with FA, four had bilateral thumb hypoplasia and three had unilateral thumb anomalies--two unilateral thumb hypoplasias and one thumb duplication. The three children with unilateral anomalies were diagnosed late, presenting with bone marrow failure. All three have subsequently died following late bone marrow transplants. This study highlights the link between unilateral radial anomalies, including thumb duplication and FA and the importance of early genetic referral for diagnosis and surveillance.