Frequency and Genetic Profile of Compound Heterozygous Friedreich's Ataxia Patients-the Brazilian Experience.

Frequency and Genetic Profile of Compound Heterozygous Friedreich's Ataxia Patients-the Brazilian Experience. Cerebellum. 2019 Jun 26;: Authors: Peluzzo TM, Bonadia LC, Donatti A, Molck MC, Jardim LB, Marques W, Lopes-Cendes IT, França MC Abstract Friedreich ataxia (FRDA) is the most common autosomal recessive ataxia in Caucasian populations. It is caused by a homozygous GAA expansion in the first intron of the frataxin gene (FXN) (OMIM: 606829) in 96% of the affected individuals. The remaining patients have a GAA expansion in one allele and a point mutation in the other. Little is known about compound heterozygous patients outside Europe and North America. We have thus designed a study to determine the frequency and mutational profile of these patients in Brazil. To accomplish that, we recruited all patients with ataxia and at least one expanded GAA allele at FXN from 3 national reference centers. We identified those subjects with a single expansion and proceeded with further genetic testing (Sanger sequencing and CGH arrays) for those. There were 143 unrelated patients (128 families), five of which had a single expanded allele. We identified point mutations in three out of these five (3/128 = 2.34%). Two patients had the c.157delC variant, whereas one individual had the novel variant c.482+1G>T. These results indicate that FXN point mutations are rare, but exist in Brazilian patients with FRDA. This has obvious implications...
Source: Cerebellum - Category: Neuroscience Authors: Tags: Cerebellum Source Type: research