Charcot ankle arthropathy in CMT1A exacerbated by type 2 diabetes mellitus.

and sensory neuropathy characterized by similar phenotype despite genetic heterogeneity1. Charcot-Marie-Tooth type 1A, linked to a ~1.4 Mb duplication containing the peripheral myelin protein-22 gene on chromosome 17p11.2, accounts for ~50% of all CMT patients2-6. Disease severity varies considerably in CMT1A, however, the prototypical phenotype involves weakness and atrophy of distal limb muscles, distal sensory deficits and diminished deep tendon reflexes with symptoms appearing in childhood7. Interestingly, increased motor and sensory impairment is observed in CMT1A patients with diabetes8. Pes cavus, a skeletal deformity resulting from characteristic sparing of foot plantar flexors in combination with early weakness of dorsiflexors, is observed in approximately twothirds of CMT1A patients7. In contrast, mutilating foot deformities resulting from prominent distal sensory deficits are not typical of CMT1A, but have been associated with the 2B subtype of CMT disease and can be a feature of the Hereditary Sensory Neuropathies9. We present a patient who developed Charcot ankle, a destructive arthritis associated with peripheral sensory neuropathy, as a result of CMT1A augmented by type II diabetes mellitus.