Neurofibromatosis Type 1 and Polydactyly

Abstract

Neurofibromatosis type 1 (NF1) is a neurocutaneous disorder that can impact the musculoskeletal system. Polydactyly is not a commonly reported skeletal feature in NF1, but the presence of several case reports in the literature raises the question of an association. We report an individual with bilateral postaxial polydactyly of the feet diagnosed with NF1. To investigate whether these findings are coincidental or nonrandom, the prevalence of polydactyly in an NF1 research database and in other reported NF1 cohorts were compared to the prevalence of polydactyly in the general population. The previously documented cases of individuals with NF1 and polydactyly certainly provoke the question of a nonrandom association between these two findings. However, there are conflicting data from the previous reports that looked at the frequency of polydactyly in NF1 populations, and the data from our database point to a coincidental association rather than a nonrandom association. While several reports have suggested a potential mechanism for the co-occurrence of polydactyly and NF1, a concrete association is still not yet well supported and caution should be used in attributing polydactyly to NF1.