These data, combined with the presence of the A502V in the NHLBI population with 0.02% frequency and our failure to identify any PD mutation carrier in our familial cohort, are consistent with the interpretation that either EIF4G1 variants are an extremely rare cause of familial PD in Caucasian cohorts, or that A502V is in fact a rare benign variant not involved in PD aetiology. This evidence concerns the gene EIF4G1 and Parkinson disease.