OBJECTIVES: Friedreich ataxia (FRDA) is a rare autosomal recessive inherited disorder that progressively causes damage to the nervous system, and, in many cases, is associated with scoliosis, heart disease, and diabetes. Although several epidemiological studies have been published, no systematic literature review has been conducted that summarizes the evidence. The objective of this study was to review existing literature that reported on the prevalence and incidence of FRDA.

METHODS: A systematic literature review was performed following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. The search was carried out in Medline and EMBASE. All studies published in English up to October 2020 that investigated the prevalence and incidence of FRDA were included. The search was complemented by handsearching the reference list of included studies. Study selection and data extraction were performed by two independent reviewers. Data extracted included methodological data (e.g. data collection period, diagnostic methods, country/region covered) and reported outcomes (e.g. prevalence, incidence).

RESULTS: A total of 277 unique records were identified, of which 26 fulfilled the inclusion criteria. Prevalence estimates ranged from 0.05 to 4.71 per 100,000 with values <1 per 100,000 reported in Brazil, Cuba, Greece, Italy, Libya and Norway; and ≥1 per 100,000 reported in Great Britain, Canada, Cyprus, Iceland, Italy, Portugal, Spain and the US. For Italy, prevalence was reported between 0.6 and 2.1 per 100,000. Highest prevalence was reported in the US and Spain, with values of 3.3 and 4.71 per 100,000, respectively.

CONCLUSIONS: This is the first study systematically reviewing and summarizing the epidemiology of FRDA. With regards to the prevalence of FRDA, it was found to be heterogeneous across different countries.