Hippocampal Trait GWAS Lead to Associations Across, Within Ancestry Groups

In Nature Genetics, members of the Chinese Imaging Genetics (CHIMGEN) consortium present findings from genome-wide association analyses and cross-ancestry GWAS meta-analyses centered on the volume of the brain's hippocampus and hippocampal subfield. Using array-based genotyping profiles for nearly 65,800 individuals with available hippocampal volume measurements and 38,977 individuals with subfield volume data, the researchers narrowed in on more than 300 variants associated with the 44 hippocampal traits considered. The variant association set encompassed almost two dozen associations not reported in the past, they note, and included an overrepresentation of variants falling in Wnt signaling and neuron differentiation pathways as well as variants implicated in processes such as cognition and neuropsychiatric disease risk. "Despite most of the identified genetic associations with hippocampal volumetric traits being shared by ancestries, we also found 5.71 [percent] ancestry-specific genetic associations," the authors report, "which may account for the inter-ancestry discrepancy in hippocampus-related phenotypes."