Variants in the Niemann-Pick type C gene NPC1 are not associated with Parkinson’s disease

Abstract

Biallelic variants in NPC1, a lysosomal gene coding for a transmembrane protein involved in cholesterol trafficking, may cause Niemann-Pick disease type C (NPC). A few cases of NPC1 mutation carriers have been reported with a Parkinson’s disease (PD) presentation. In addition, pathological studies demonstrated phosphorylated alpha-synuclein and Lewy pathology in brains of NPC patients. Therefore, we aimed to examine whether NPC1 genetic variants may be associated with PD. Full sequencing of NPC1 was performed in 2,657 PD patients and 3,647 controls from three cohorts, using targeted sequencing with molecular inversion probes. A total of 9 common variants and 126 rare variants were identified across the three cohorts. To examine association with PD, regression models adjusted for age, sex and origin were performed for common variants, and optimal sequence Kernel association test (SKAT-O) was performed for rare variants. After correction for multiple comparisons, common and rare NPC1 variants were not associated with PD. Our results do not support a link between heterozygous variants in NPC1 and PD.