Rare Variants Analysis of Cutaneous Malignant Melanoma Genes in Parkinson’s Disease

Abstract A shared genetic susceptibility between cutaneous malignant melanoma (CMM) and Parkinson’s (PD) has been suggested. We investigated this by assessing the contribution of rare variants in genes involved in CMM to PD risk. We studied rare variation across 29 CMM risk genes using high quality genotype data in 6,875 PD cases and 6,065 controls and sought to replicate findings using whole exome sequencing data from a second independent cohort totaling 1,255 PD cases and 473 controls. No statistically significant enrichment of rare variants across all genes, per gene or for any individual variant was detected in either cohort. There were non-significant trends towards different carrier frequencies between PD cases and controls, under different inheritance models, in the following CMM risk genes: BAP1 , DCC , ERBB4, KIT , MAPK2 , MITF , PTEN and TP53 . The very rare TYR p.V275F variant, which is a pathogenic allele for recessive albinism, was more common in PD cases than controls in three independent cohorts. Tyrosinase, encoded by TYR is the rate limiting enzyme for the production of neuromelanin, and has a role in the production of dopamine. These results suggest a possible role for another gene in the dopamine-biosynthetic pathway in susceptibility to neurodegenerative Parkinsonism, but further studies in larger PD cohorts are needed to accurately determine the role of these genes/variants in disease pathogenesis.