GJB1 and hereditary motor and sensory neuropathy: In demyelinating forms of hereditary motor and sensory neuropathy (HMSN), also known as CMT1 or CMT4, associated genes include GDAP1, MTMR2, SBF2, NDRG1, EGR2, SH3TC2, PRX, FGD4, PMP22, GJB1, MPZ, MFN2, MED25, and FIG4.