As expected, AAs carried more rare variants than EAs (because they represent an older population), and most variants were population-specific. In both populations, comparison subjects had a higher frequency of rare nonsynonymous variants in the exon 5 cytoplasmic loop region than cases. The difference was significant in AAs (FET p=0.01, WSM p=0.008), but not in EAs (FET p=0.29, WSM p=0.35). However, a missense mutation p.Pro451Leu, which was exclusively observed in EAs, was found in 8 comparison subjects, but only in 2 ND cases. The difference in frequency of this rare variant is marginally significant (FET p=0.05), potentially indicating a protective effect against ND.
