Estudos moleculares em ataxia de Friedreich

Peluzzo, Thiago Mazzo, Advisor: França Junior, Marcondes Cavalcante; TESE DIGITAL 2017

We therefore designed this study to determine the frequency, phenotypic and mutational profile of Brazilian patients that presented compound heterozygosity for FXN. To accomplish that, we recruited patients from 3 national reference centers (State University of Campinas-UNICAMP, São Paulo University at Ribeirão Preto-USP-RP and Federal University of Rio Grande do Sul-UFRGS). Those patients with a single identified expansion underwent sequencing of all 5 exons and exon-intron boundaries at FXN (Sanger technique). We identified a novel variant (c.482+1G>T) considered pathogenic following American College of Medical Genetics and Genomics (ACMG) guidelines. In addition, another pathogenic variant previously described in the literature (c.157delC) was found in 2 unrelated subjects. Compound heterozygosity accounted for 2.87% (5/174) of all patients; however, when considered only cases in which point mutations were found, the rate decreases to 1,72% (3/174). These are novel data for the Brazilian population. From a clinical perspective, they will help the choice of adequate techniques for FRDA diagnosis and proper genetic counseling in our country.