Can Be Homozygous or Can Be Compound Heterozygous
CMT2B2 is caused by autosomal recessive mutations in the MED25 gene. CMT2B2 was first identified in a single family in Costa Rica. CMT2B2 is also known as Autosomal Recessive CMT2B, or AR-CMT2B for short.
CMT2B2 symptoms usually start to occur in the CMTer’s late 20s to early 30s. CMTers who have CMT2B2 will usually experience weakness, atrophy, and sensory loss in their feet and in their hands. The weakness and atrophy lead to foot deformities such as high arches and hammertoes; and the weakness and atrophy lead to loss of range-of-motion in the hands as well as contractures (clawed hands).
CMTers who have CMT2B2 usually experience a slow progression following symptom onset, and disease severity is widely variable.