Biallelic Variants in EPG5 Gene Are Associated with Parkinson's Disease.

Abstract

Objective: Despite substantial advancements in uncovering the genetic basis of Parkinson's disease (PD), a significant portion of cases characterized by familial PD remain genetically elusive. Here, we reported that biallelic variants in EPG5, a key autophagy gene responsible for Vici syndrome, are associated with PD.

Methods: Whole-exome sequencing (WES) was performed in the first cohort including 171 pedigrees with autosomal recessive PD (ARPD), 1,746 cases of sporadic early-onset PD (sEOPD, age at onset ≤ 50 years) and 1,652 healthy controls. Whole-genome sequencing (WGS) was performed in the second cohort consisting of 1,947 sporadic late-onset PD (sLOPD, age at onset >50 years) and 2,478 healthy controls.

Results: We identified 7 participants harboring compound heterozygous variants within the EPG5 gene across 1 family with ARPD (ARPD-F1), 4 sporadic EOPD cases, and 1 sporadic LOPD individual. A total of 10 novel variants in EPG5 were discovered in the 7 individuals, comprising 3 nonsense variants and 7 missense variants. The compound heterozygous variants in the EPG5 gene led to decreased expression of EPG5 protein, and impaired autophagy-lysosome function in cells derived from EPG5-PD individuals. We also revealed several key pathological features, including abnormal accumulation of autophagic vacuoles, aggregation of α-synuclein in skin tissue from EPG5-PD individuals. In mice, EPG5 deficiency led to progressive dopaminergic neurodegeneration in the substantia nigra of the midbrain.

Interpretation: Our results unveil a novel association between biallelic variants in EPG5 gene and PD, providing compelling initial evidence for the involvement of EPG5 and autophagy dysregulation in the development of PD. ANN NEUROL 2025.