Charcot-Marie-Tooth syndrome.
Charcot-Marie-Tooth syndrome (CMT) is a group of genetically determined symmetric distal polyneuropathies. The CMT loci are known to map to chromosome 1 (CMT1B), chromosome 17 (CMT1A), the X chromosome (CMTX), and two additional unknown autosomes (CMT1C and CMT2). The most prevalent form is CMT1A, an autosomal dominant demyelinative disorder caused either by a tandem duplication in band p11.2-12 of chromosome 17 (17p11.2-12) with trisomic expression of the peripheral myelin protein-22 (PMP-22) gene or, less frequently, by a missense mutation of PMP-22. Missense mutations in PMP-22 are also responsible for two forms of demyelinative polyneuropathy in mice, trembler and trembler. Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant disorder characterized by recurrent focal neuropathy. In all families thus far studied, patients with HNPP have been found to be monosomic for a segment of chromosome 17p11.2-12. The duplication in CMT1A and deletion in HNPP map to the same region in 17p11.2-12 and are both likely to be consequences of unequal crossing over during germ cell meiosis.
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Department of Pediatrics, University of Utah Medical Center, Salt Lake City.
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D000818:Animals; D002607:Charcot-Marie-Tooth Disease / Q000235:genetics* / Q000503:physiopathology; D002871:Chromosome Banding; D002874:Chromosome Mapping; D002878:Chromosomes, Human, Pair 1; D002886:Chromosomes, Human, Pair 17; D003434:Crossing Over, Genetic; D017353:Gene Deletion; D008040:Genetic Linkage; D006801:Humans; D008540:Meiosis; D051379:Mice; D009154:Mutation; D009185:Myelin Proteins / Q000235:genetics; D010523:Peripheral Nervous System Diseases / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D014960:X Chromosome
D009185:Myelin Proteins; C073687:PMP22 protein, human; C489545:Pmp22 protein, mouse