Table 3.

The minor allele at rs356182 near SNCA associates with tremor‐predominant phenotypes in discovery and replication cohorts

Covariates	Discovery cohort				Replication cohort
	Co‐dominant		A‐allele dominant		Co‐dominant		A‐allele dominant
	β	P‐value	β	P‐value	β	P‐value	β	P‐value
Age + sex	0.55	0.029	0.56	0.015	0.31	0.128	0.42	0.020
Age + sex + disease duration	0.65	0.008	0.62	0.006	0.32	0.107	0.42	0.018
Age + sex + disease duration + LEDD	0.70	0.004	0.65	0.003	0.31	0.125	0.41	0.021
Age + sex + disease duration + LEDD + site					0.31	0.125	0.42	0.018

Linear regressions were used to evaluate associations between genotypes at rs356182 and tremor‐predominant (TD) versus postural instability gait disorder (PIGD) phenotypes. TD/PIGD ratios were predicted by genotype under codominant versus major allele (A)‐dominant genetic models, with covariates as indicated. In the codominant model, the coefficient represents the effect size for each additional G allele; in the A‐dominant model, the coefficient represents the effect size for the GG genotype. The discovery cohort consisted of 251 PD patients from the University of Pennsylvania, while the replication cohort consisted of 559 PD patients from multiple clinical sites.