Renaud M, et al. - Researchers intended to improve the clinical, biomarker, and molecular delineation of ataxia with oculomotor apraxia type 1 (AOA1) and provide genotype-phenotype correlations. Findings revealed that the α-fetoprotein (AFP) level (slightly elevated in a substantial fraction of patients) could constitute a new biomarker for AOA1. In AOA1, oculomotor apraxia could be an optional finding and associated with the more severe disease. In the white population, the p.Trp279* mutation was the most frequent aprataxin gene (APTX) mutation. APTX missense mutations could be related to milder phenotype.