An independent replication of PARK16 in Asian samples

Parkinson disease (PD) is the most common neurodegenerative movement disorder with age-related prevalence. Approximately 1% of the population is affected at 65 years, which increases to 4%–5% in 85-year-olds.¹ To date, several loci containing pathogenic or risk variants have been identified; the most recent, PARK16, was nominated through 2 genome-wide association studies (GWAS) using samples of Japanese and European ancestry.^2,3 This new locus, located in 1q32, was originally identified in the Asian study with p values ranging from 10⁻⁷ to 10⁻¹². PARK16 did not reach significance level in the European GWAS or its replication (p value >10⁻⁴); however, combining samples from stage I and II indicated an association. The most significant SNP in the European study (rs823128) showed a 1% difference in minor allele frequency (MAF) between patients with PD (4%) and control subjects (3%), resulting in an odds ratio (OR) of 0.66 (p value = 7.3 × 10⁻⁸) (of note, the allele frequencies seem to have been mistakenly switched in the combined analysis).³ In contrast, the MAF of rs823128 appears to be more common in the Japanese population, with a lower frequency in patients with PD (10%) …