Genome-wide association study of population-standardised cognitive performance phenotypes in a rural South African community

Cognitive function is an indicator for global physical and mental health, and cognitive impairment has been associated with poorer life outcomes and earlier mortality. A standard cognition test, adapted to a rural-dwelling African community, and the Oxford Cognition Screen-Plus were used to capture cognitive performance as five continuous traits (total cognition score, verbal episodic memory, executive function, language, and visuospatial ability) for 2,246 adults in this population of South Africans. A novel common variant, rs73485231, reached genome-wide significance for association with episodic memory using data for similar to 14 million markers imputed from the H3Africa genotyping array data. Window-based replication of previously implicated variants and regions of interest support the discovery of African-specific associated variants despite the small population size and low allele frequency. This African genome-wide association study identifies suggestive associations with general cognition and domain-specific cognitive pathways and lays the groundwork for further genomic studies on cognition in Africa. A genome-wide association study for five cognitive phenotypes in a rural South African community suggests several variants associated with general cognition and domain-specific cognitive pathways in this cohort.

Automated summary

Cognitive function is important for overall physical and mental health. This study used cognitive tests to assess 2,246 adults in a rural South African community and found a genetic variant associated with episodic memory. Despite the small population size, the study provides insights into cognitive pathways specific to Africans and paves the way for further genomic research on cognition in Africa.