Chunk #31 — FROM GENE DISCOVERY TO POLYGENICITY: POLYGENIC AND WITHIN‐FAMILY APPROACHES TO ILLUMINATE MECHANISMS OF GENETIC RISK — Within‐family comparisons
polygenic analyses. Biological full siblings reared together share the same home environment and a substantial portion of their genetic variation (50% on average), allowing for control of measured and unmeasured familial factors such as socioeconomic status, religious upbringing, urban–rural residency, parental education, and familial polygenic load, that are also known to influence AUD and related outcomes. In recent analyses of 1226 EA sibling groups nested within the overall COGA sample, we aimed to elucidate the associations between polygenic scores for educational attainment and clinical criterion counts for three substance use disorders (alcohol, nicotine, and cannabis). 117 Subtle differences in polygenic loading for educational attainment were associated with SUD outcomes, such that siblings who carried more alleles associated with educational attainment tended to meet fewer clinical criteria for alcohol, nicotine, and cannabis use disorders.
