[Detection of the PMP22 gene duplication in peripheral neuropathy patients: a study in Mexican population]

Charcot-Marie-Tooth disease (CMT) is a neuropathy that affects sensory and motor nerves. The most common CMT subtype is CMT1A due to a PMP22 duplication of a 1.5 Mb fragment on the 17p11.2-p12. The development of a specific molecular technique that detects the PMP22 duplication is necessary for the diagnosis of CMT1A.

To establish a routinary test for detection of the PMP22 gene duplication in Mexican population and to estimate the CMT1A frequency in patients clinically diagnosed as CMT.

A cohort of 157 individuals clinically diagnosed as CMT were analyzed. The detection of the PMP22 gene duplication was performed using the comparative 2-ΔΔCT qPCR method.

The comparative 2-ΔΔCT method was sensitive and reliable for the detection of the PMP22 duplication. In order to validate the testing, data was compared with FISH results. Duplication of PMP22 was detected in 79 patients (50.3%). Although CMT1A frequency is different among populations, in Mexican patients it was similar with other populations such as United States, Australia, Finland, Sweden and Spain.

The qPCR technique is an accurate and inexpensive method for the diagnosis of CMT1A. This method can be routinely used in Mexico where CMT1A represents ≍ 50% of CMT cases. Molecular diagnosis of CMT1A is essential for the genetic counseling and treatment of patients.