Genetic and Epidemiological Insights into RAB32-Linked Parkinson's Disease

Background: The p.Ser71Arg RAB32 variant was recently associated with Parkinson's disease (PD). Objective: The aim was to investigate the presence of RAB32 variants in a large multiethnic group of individuals affected and unaffected by PD. Methods: We queried our proprietary database that contains exome/genome sequencing data of >180,000 individuals. Additional PD patients were genotyped, and proximal p.Ser71Arg-associated haplotypes were constructed. Results: p.Ser71Arg was present in 11 PD patients (73% from northern Italy) and in 35 individuals (89% from the Middle East and North Africa [MENA]) aged <50 years without PD-relevant symptoms. It was found in-cis to a set of proximal single-nucleotide polymorphisms. Additional RAB32 variants were comparably frequent in PD and non-PD individuals. Conclusions: The RAB32 p.Ser71Arg variant defines a cluster of PD patients in northern Italy. Globally, it is most prevalent in MENA. Our data indicate that p.Ser71Arg causes PD and that it occurred only once, through a founder event. Other RAB32 variants are unlikely to cause PD. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.