Friedreich's ataxia, review and literature update with a systematic search for cases in Latin America

Abstract

Friedreich Ataxia (FA) is an autosomal recessive neurodegenerative disease with multisystemic involvement. This update of epidemiological, pathophysiological, and clinico-therapeutic aspects of FA, includes a systematic review of cases in Latin America. The estimated FA prevalence in Caucasian populations is between 2 to 5 cases per 100 000. In Latin America, 1481 cases have been published in 35 articles from six different countries. Caused by an abnormally repeated expansion of GAA trinucleotide inside the FXN gene, FA's etiopathogenesis is associated with reduced levels of the frataxin protein, which disturb the energy metabolism and result in mitochondrial iron accumulation. The classic phenotype usually show symptoms before the age of 25, although there are others with a later onset. The main symptoms of AF are progressive ataxia, sensory disturbances, areflexia, dysarthria, and oculomotor alterations, in addition to cardiac, endocrine, and musculoskeletal compromise. Diagnostic workup requires a detailed neurological examination, neuroconduction studies, neuroimaging, and biochemical tests. The definitive diagnosis is provided by genetic testing showing biallelic variants within the FXN gene. The management is multidisciplinary, aimed at reducing symptoms, preventing complications, and providing an appropriate genetic counseling. Recently, the first pharmacological treatment for AF has been approved, with several others in clinical assessment trials.