A nonsynonymous LRRK2 (MIM: 609007) variant that causes Parkinson disease (MIM: 607060) was associated with an odds ratio of 4.76 (95% CI [3.25, 6.96]) that a person would have a parent with Parkinson disease; this estimate is consistent with studies of affected family members.47, 48, 49 A nonsynonymous PER3 (MIM: 603427) variant previously classified as pathogenic for advanced sleep phase syndrome (MIM: 616882) had an odds ratio of only 1.38 for being a morning person and advanced sleep timing by only 8 minutes, 95% CI ([4, 13])50, 51 compared to a reported 4.2 hour shift in midpoint sleep. Here, LRRK2 is linked to Parkinson disease.