From Citizendium - Reading time: 2 min
Peripheral nerve myelin protein 22 (PMP22) is clinically significant in several genetic peripheral neuropathies.[1] These include the several subclasses of Charcot-Marie-Tooth disease (CMT), with loci mapping to chromosome 17 (CMT1A), chromosome 1 (CMT1B) and to another unknown autosome (CMT1C), as well as hereditary neuropathy with sensitivity to pressure palsies (HNPP), an autosomal dominant disorder that results in a recurrent, episodic demyelinating neuropathy.
CMT1A and HNPP are reciprocal duplication/deletion syndromes[2] originating from unequal crossover during germ cell meiosis.[1] HNPP is associated with a 1.5-Mb deletion in chromosome 17p11.2-12 and results from reduced expression of the PMP22 gene. [3]
In hereditary motor and sensory neuropathy type 1a (HMSN1a), the level of anti-PMP22 antibody indicated a trend toward the progression of disease. [4]
An inflammatory polyneuropathy may become superimposed on patients with CMT. This inflammation has been treated with corticosteroids and intravenous immune globulin (IVIG).[5]