Abstract
BACKGROUND: The SLC25A46 gene encodes a mitochondrial carrier protein previously implicated in neuropathy and optic atrophy. Biallelic variants in SLC25A46 have been described in patients with Parkinson's disease (PD) with optic atrophy, but the evidence supporting a role in PD remains limited. OBJECTIVE: To assess whether SLC25A46 variants contribute to PD, REM sleep behavior disorder (RBD), or Dementia with Lewy Bodies (DLB). METHODS: We examined common variants using four representative PD genome-wide association studies (GWAS) and an RBD GWAS and applied Summary-data-based Mendelian Randomization (SMR) to evaluate whether genetically regulated expression of SLC25A46 shows a causal association with the risk of PD or RBD. Rare variant analyses were conducted in four cohorts of European descent: Accelerated Medicines Partnership: Parkinson's Disease (AMP-PD) PD (3,051 PD, 3,667 controls), UK Biobank (3,267 PD, 14,939 proxy, 54,800 controls), RBD (1,376 RBD, 2,580 controls), and AMP-PD DLB (2,605 DLB, 1,894 controls). Optimal Sequence Kernel Association test (SKAT-O) and meta-analysis were used to assess rare variants. RESULTS: No associations were observed between SLC25A46 variants and PD, RBD, or DLB. SMR analyses revealed no evidence supporting a causal relationship between SLC25A46 expression and PD or RBD risk. Rare variant burden analyses did not identify significant associations after multiple-testing correction across cohorts or meta-analyses. CONCLUSION: SLC25A46 variants showed no evidence of association, suggesting the gene does not play a major role in PD, RBD, or DLB risk.