Diagnosis of the peripheral hereditary neuropathies and its molecular genetics

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Acta Ortop Mex. 2008 Jul-Aug;22(4):268-77.

Diagnosis of the peripheral hereditary neuropathies and its molecular

genetics

Hernández-Zamora E, Arenas-Sordo Mde L.

Servicio de Genética, Instituto Nacional de Rehabilitación, Av.

México-Xochimilco Núm, 289, Arenal de Guadalupe, Tlalpan C.P. 14389,

DF México.

Peripheral neuropathies include a wide range of pathological

disorders characterized by damage of peripheral nerves. Among them,

peripheral hereditary neuropathies are a group of frequent illnesses

and early evolution. They have been named hereditary motor and

sensory neuropathy (HMSN) or peripheral hereditary neuropathies type

Charcot-Marie-Tooth (CMT).

The most frequent types are CMT1, CMT2 and CMTX. Approximately 70% of

the cases correspond to subtype CMT1A, associated with tandem

duplication of a 1.5 Mb DNA fragment on chromosome 17p11.2-p12 that

codifies the peripheral myelin protein PMP22.

So far, there five different types of CMT (1,2,3,4,X) with

approximately 32 subtypes, associated with more than 30 genes.

Have been reported genetic heterogeneity and expression variability

of the illness makes it necessary to carry on diagnostic strategies

that integrate clinical study for determining genetic clinical

history, family history, complete physical exploration, muscular

strength, physical deformities, reflexes and sensitivity, and

molecular studies allow detection of different types of mutations and

help establish a correct diagnosis and an adequate genetic counseling.