Haploinsufficiency is a loss-of-function mechanism in which a single functional copy of a gene does not make enough product for normal function, so losing or inactivating one copy is enough to cause disease. It marks a dosage-sensitive gene. In CMT, HNPP results from the loss of one PMP22 copy, the reciprocal of the CMT1A duplication.
A Name That Does Too Much Work
Jean-Martin Charcot's name appears throughout medicine, but nowhere does it create more confusion than in the foot. Learn why the CMT foot and Charcot neuroarthropathy, also known as Charcot foot, share a name yet differ in how they develop, appear, and are managed.
