ABSTRACT
The p.Thr124Met mutation in the myelin protein zero (MPZ) causes the Charcot-Marie-Tooth disease type 2J, a peripheral neuropathy with additional symptoms as pupillary alterations and deafness. It was observed in several families around the world originating e. g. from Germany, Belgium, Japan, Italy and North America. Here we report Central American patients originating from a family in Costa Rica carrying this mutation. Clinical, electrophysiological and molecular analysis of patients and controls were performed, including gene and linked markers´ sequencing. Carriers share almost the entire haplotype with two non related Belgian CMT patients. As a result of the haplotype analysis, based on ten markers (seven SNPs, two microsatellites and an intronic polyA stretch), the founder effect hypothesis for this allele migration is suggestive. Rev. Biol. Trop. 62 (4): 1285-1293. Epub 2014 December 01.
La mutación p.thr124Met en la proteína mielina cero (MPZ) causa la enfermedad de Charcot-Marie-Tooth tipo 2J, una neuropatía periférica con síntomas adicionales como alteraciones pupilares y sordera. Se ha observado en varias familias alrededor del mundo, originarias de Alemania, Bélgica, Japón, Italia y Norteamérica, entre otras. Aquí reportamos a pacientes centroamericanos provenientes de Costa Rica que acarrean esta mutación. Se realizaron análisis clínico, electrofisiológico y molecular de pacientes y controles, incluyendo secuenciación del gen y de marcadores ligados a éste. Estos pacientes comparten casi por completo el haplotipo con dos pacientes belgas no emparentados. Como resultado del análisis de los haplotipos, basado en diez marcadores (siete SNPs, dos microsatélites y un elemento poli-A intrónico), se sugiere que se ha dado un efecto fundador en la migración de este alelo.
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Charcot-Marie-Tooth Disease/genetics , Hearing Loss, Sensorineural/genetics , Myelin P0 Protein/genetics , Point Mutation/genetics , Case-Control Studies , Costa Rica , Charcot-Marie-Tooth Disease/ethnology , Founder Effect , Haplotypes , Hearing Loss, Sensorineural/ethnology , PedigreeABSTRACT
Hereditary motor and sensory neuropathy (HMSN) or Charcot-Marie-Tooth disease (CMT) is the most common hereditary illness of the peripheral nervous system. The genetics and the physiopathological aspects of the disease clarified until know, are here summarized. More than twenty genes and ten additional loci have been related with HMSN. These findings contribute to understand the metabolism of peripheral nerves and give the basis for molecular diagnostics and future therapy. Several Costa Rican families with CMT have been identified, specially with axonal forms. Two families present mutations in the myelin protein zero gene (IMPZ). In addition, linkage have been found between the disease and locus 19q13.3 in an extended family, and a mutation segregating with the disease is present in a candidate gene of the critical interval. Costa Rica has several advantages for genetical studies, that can contribute importantly in the generation of knowledge in the neurogenetical field.