Charcot–Marie–Tooth: Are you testing for proteinuria?

Charcot–Marie–Tooth disease (CMT) is a clinically and genetically heterogeneous group of inherited disorders affecting motor and sensory nerves of the peripheral nervous system. CMT has been reported to be associated with renal diseases, mostly focal segmental glomerulosclerosis (FSGS). However, it was unknown whether these two clinical manifestations represent one common underlying disorder or separate disease entities. Several reports have shown a high prevalence of mutations (75%) in the inverted formin gene (INF2) in patients with CMT-associated glomerulopathy, suggesting that these mutations are a common cause of the dual phenotype. For this reason, we strongly suggest to screen for proteinuria in CMT patients, in order to identify patients with this renal-neurologic phenotype in an early stage, and to perform genetic testing for INF2 mutations.