Clinical features on Friedreich’s ataxia patients in São Paulo, Brazil

Background: There are few reports characterizing Friedreich´s Ataxia (FRDA) phenotype beyond Europe and USA. Objective: Herein, we describe the clinical profile of a representative FRDA cohort from São Paulo, Brazil. Methods: Patients were invited to answer an online survey comprising 24 to 32 questions, which was sent by physicians and the Brazilian Association of Acquired and Hereditary Ataxias via email and releases. We collected data on sex, current age, age at diagnosis, affected relatives, parental consanguinity, ability to walk, the need of ambulatory assistive device or wheelchair and presence of diabetes, cardiomyopathy, and scoliosis. Descriptive statistics was used to report the results - means, proportions, and Standard Deviations (SD). Age at loss of ambulation (LOA) was assessed both for classical and late-onset (LOFA) groups using Kaplan-Meier curves. Results: We gathered 104 answers from FRDA patients or legal guardians, being 79 (75.9%) patients with classical FRDA and 25 (24%) with late-onset (LOFA) . There were 64 (61.5%) women and 40 (38.5%) men. Mean age and age at diagnosis were 37.3±13.8 and 24.1±11.5 years, respectively. Parental consanguinity and familial disease recurrence were seen in 24 (23%) and 50 (48.7%) of the patients, respectively. Fifty five out of 104 patients lost ambulation at the mean age of 29.4±11.5 years. Those who are still ambulatory but need assistive devices, first required them at a mean age of 27.1±13.1 years. As expected, patients with classical FRDA had LOA earlier than LOFA (25.5±7.7 vs 47.8±10.2 years). The frequency of diabetes, cardiomyopathy, hearing impairment and scoliosis in this cohort was 36±10.9, 23.6±14.2, 32.5±8.8 and 18.5±9.1, respectively. Conclusion: The overall phenotype of FRDA in Brazil is similar to previous European and US reports, but age at LOA was slightly higher. Further studies are needed to better understand such difference.