CMT 1A: Strategies for clinical & molecular diagnosis in Mexican patients

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Gac Med Mex. 2007 Sep-Oct;143(5):383-9.

Strategies for clinical and molecular diagnosis of Charcot-Marie-

Tooth 1A among Mexican patients

Hernández-Zamora E, Arenas-Sordo Mde L, Escobar-Cedillo RE, González-

Huerta NC, Leyva-García N, Maldonado-Rodríguez R.

Servicio de Genética, Instituto Nacional de Rehabilitación, Deleg.

Tlalpan, México DF, México

BACKGROUND: Charcot-Marie-Tooth (CMT) is the most common inherited

disorder of the human peripheral nerve. The most frequent subtype,

CMT1A, is associated with duplication of approximately 1.5 Mb

fragment in 17p11-p12, that includes the PMP22 gene.

OBJECTIVE: The aim of this study was to describe different strategies

used for clinical and molecular CNT1A diagnoses among patients

attending the National Rehabilitation Institute of Mexico (INR).

MATERIAL AND METHODS: 17 patients had clinical and

electrophysiological features compatible with CMT1. A molecular study

using capillary electrophoresis (CE) was performed and a PMP22 gene

duplication was detected.

RESULTS: Clinical, biochemical and electrophysiological studies

constituted the inclusion criteria to establish a CMT1 diagnosis.

With CE the duplication of the PMP22 gene was observable and we

established a possible CMT1A diagnosis in seven patients. All

duplications detected by capillary electrophoresis were corroborated

using FISH.

CONCLUSION: CE is a feasible and reliable method to detect PMP22 gene

duplication. Using different clinical, electrophysiological and

molecular strategies in this patient population allowed us to

establish an accurate diagnosis and offer suitable genetic counseling.