Autosomal Dominant or Recessive
Can Be Heterozygous, or Can Be Homozygous, or Can Be Compound Heterozygous
CMT2T is caused by autosomal dominant and autosomal recessive mutations in the MME gene.
CMT2T is exceedingly rare. CMT2T was first reported by Higuchi et al., (2016). The report was of 10 unrelated Japanese CMTers with adult-onset peripheral neuropathy that was consistent with a Type 2 CMT. Most of these 10 CMTers had one or more similarly affected family members, and 6 of the families were consanguineous (parents were close blood relatives). Symptom onset was between 36 and 56, and all patients had slowly progressive weakness and atrophy of the distal (farthest points from the center of the body) lower limb muscles, resulting in gait disturbances, although none were wheelchair-bound. All also had distal (points farthest away from the center of the body) sensory impairment and hyporeflexia (under-reactive reflexes).