Finally, we found three individuals with fLOPD due to a pathogenic repeat expansion in ATXN2. Although typically manifesting as spinocerebellar ataxia 2 (OMIM #183090), ATNX2 expanded CAG trinucleotide repeats have been identified in PD cases across multiple ancestries, most often in association with a family history of autosomal dominance75–79. Here, ATXN2 is linked to Parkinson disease.