Friedreich ataxia (FRDA) is an autosomal recessive disorder due to mutations in the FXN gene. FRDA is characterized by the classical triad of ataxia, absent reflexes, and Babinski sign, but atypical presentations might also occur. Our aims were to describe the proportion of FRDA diagnoses in suspected families living in Rio Grande do Sul, South Brazil, and to estimate a minimum frequency of symptomatic subjects. Subjects that were evaluated by molecular analysis for FRDA at the Hospital de Clínicas de Porto Alegre were identified in our files. Patients’ clinical manifestation and phenotypes were described and compared. The number of FRDA subjects alive in the last 5 years was determined. One hundred fifty-six index cases (families) were submitted to evaluation of GAA repeats at FXN since 1997: 27 were confirmed as FRDA patients. Therefore, the diagnostic yield was 17.3%. Proportion of classical, late onset, and retained reflexes subphenotypes were similar to those described by other studies. A minimum prevalence was estimated as 0.20:100.000 inhabitants. In conclusion, we verified that this FRDA population displayed the usual clinical characteristics, but with a lower period prevalence than those obtained in populations from Europe.
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This study was supported by the Fundo de Incentivo à Pesquisa do Hospital de Clínicas de Porto Alegre (FIPE-HCPA) (GPPG 17-0600). SLS, MLSP, and LBJ were supported by the Conselho Nacional de Pesquisa (CNPq).
Compliance with Ethical Standards
This study was approved by the local ethical committee under the registry number CAAE 79117317.2.0000.5327.
Conflict of Interest
The authors declare that they have no conflict of interest.
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