In a meta-analysis of genome-wide association study (GWAS) data based on the genotypes of 2,525,705 SNPs in 4238 PD cases and 4239 non-PD controls, a total of 3 SNPs were found to be statistically associated with PD, including a non-synonymous missense variant in HSD3B7 (hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 7) (Song and Lee, 2013). This evidence concerns the gene HSD3B7 and Parkinson disease.