Compound Heterozygous Mutations of in a Korean Cohort Study of Charcot-Marie-Tooth Disease Concurrent Cerebellar Ataxia and Spasticity.

Mutations in the gene are associated with autosomal recessive spastic ataxia of Charlevoix-Saguenay disease (ARSACS) or complex clinical phenotypes of Charcot-Marie-Tooth disease (CMT). This study aimed to identify mutations in a Korean CMT cohort with cerebellar ataxia and spasticity by whole exome sequencing (WES). As a result, eight pathogenic mutations in four families were identified as the underlying causes of these complex phenotypes. The prevalence of CMT families with mutations was determined to be 0.3%. All the patients showed sensory, motor, and gait disturbances with increased deep tendon reflexes. Lower limb magnetic resonance imaging (MRI) was performed in four patients and all had fatty replacements. Of note, they all had similar fatty infiltrations between the proximal and distal lower limb muscles, different from the neuromuscular imaging feature in most CMT patients without mutations who had distal dominant fatty involvement. Therefore, these findings were considered a characteristic feature in CMT patients with mutations. Although further studies with more cases are needed, our results highlight lower extremity MRI findings in CMT patients with mutations and broaden the clinical spectrum. We suggest screening for in recessive CMT patients with complex phenotypes of ataxia and spasticity.