Early-onset axonal Charcot-Marie-Tooth disease due to SACS mutation

Abstract

Axonal Charcot-Marie-Tooth disease (CMT) represents an expanding group of inherited motor and sensory neuropathies in clinical practice. SACS-gene related disorders have been associated with complex neurological phenotypes of early-onset cerebellar ataxia, spastic-ataxia, spastic paraplegia, demyelinating neuropathy and variable ophthalmological, cognitive and psychiatric disturbances, but never related to pure axonal neuropathy phenotypes. Two unrelated Brazilian men with early-onset axonal CMT-like presentations associated with SACS gene mutations are presented. Both patients presented with pure sensorimotor axonal neuropathy without cerebellar ataxia, spastic paraplegia or other systemic and neurological involvement. Classical neuroimaging findings observed in other sacsinopathies were observed in both cases. Homozygous pathogenic mutations were found in SACS gene in both patients. SACS gene mutations can be associated with pure axonal sensorimotor neuropathy without other neurological features, but with typical neuroimaging features of other sacsinopathies, disclosing the importance of performing neuroimaging studies in patients with suspected axonal CMT.

Keywords: Axonal neuropathy; Charcot-Marie-Tooth disease; Hereditary neuropathy; Sacsinopathy.