CMT 1A: Utility of STR markers for the molecular diagnosis of a large Brazilian

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Genet Mol Res. 2008 Oct 28;7(4):1179-85.

Utility of STR markers for the molecular diagnosis of a large

Brazilian family with Charcot-Marie-Tooth disease.

Possamai CO, Carvalho FM, Silva MF, Wolfgramm EV, Sartori MP, Malta

FS, Ribeiro VP, Spina VP, Gomes KB, Ferreira AC, Louro ID.

Departamento de Ciências Biológicas, Centro de Ciências Humanas e

Naturais, Núcleo de Genética Humana e Molecular, Universidade Federal

do Espírito Santo, Vitória, ES, Brasil.

Charcot-Marie-Tooth type 1A disease (CMT1A) is most frequently caused

by a tandem DNA duplication of a 1.4-Mb genomic fragment in the

17p11.2-12 chromosomal region. The disease is probably the product of

a dosage effect of the peripheral myelin protein 22 gene located

within the duplicated segment.

We sought to study the largest reported Brazilian family with

suspected diagnosis of CMT1A using eight short tandem repeat

microsatellite markers. In addition, we analyzed the informativeness

of these markers in the normal Brazilian population.

The duplication was found in 12 members of the family. In two

patients with CMT1A symptoms, the duplication was not detected, and

one asymptomatic subject showed the duplication. D17S2230, D17S9B,

D17S2220, D17S2227, D17S9A, and D17S4A markers showed the highest

heterozygosity rates, and D17S2228 and D17S2224 markers were the

least informative in our analysis.