Hereditary Motor and Sensory Neuropathy, CMT2B2 - MED25

Klinische Symptomatik

CMT2B2 represents a classical, axonal HMSN disease. Patients reveal a distally pronounced, symmetric muscle atrophy, pes cavus, as well as reduced sensory perception. Age of onset is in the third to fourth decade of life. The course of the disease is mild, the progression slow.

Genetik

CMT2B2 is caused by mutations in the MED25 (Mediator subunitt 25) gene and follow an autosomal recessive pattern of inheritance. MED25, synonymous to ARC92 and ACID1, represents a subunit of the "activator-recruited cofactor (ARC), which belongs to the family of coactivators of transcription. The exact physiological function is unknown.
CMT2B2 is located on chromosome 19q13.3; the mutation p.Ala335Val causes CMT2B2 in an extended Costa Rican family.

Häufigkeit

Rare

 

Diagnostik