Study Traces Friedreich Ataxia's Uneven Global Spread to FXN 'Protomutations'

• •A study led from the University of Oklahoma Health Sciences Center reports that the disease-causing GAA repeat expansions in the FXN gene arise from precursor alleles the authors call 'protomutations'.
• •These protomutation alleles are found in Eurasian populations but not in sub-Saharan Africa, which the authors say explains why Friedreich ataxia is largely confined to people of European and Asian descent.
• •The paper appeared in Human Molecular Genetics on 9 June 2026 (Volume 35, Issue 11).