Increasing sample diversity in psychiatric genetics - Introducing a new cohort of patients with schizophrenia and controls from Vietnam - Results from a pilot study.

Abstract

OBJECTIVES\nGenome-Wide Association Studies (GWAS) of Schizophrenia (SCZ) have provided new biological insights; however, most cohorts are of European ancestry. As a result, derived polygenic risk scores (PRS) show decreased predictive power when applied to populations of different ancestries. We aimed to assess the feasibility of a large-scale data collection in Hanoi, Vietnam, contribute to international efforts to diversify ancestry in SCZ genetic research and examine the transferability of SCZ-PRS to individuals of Vietnamese Kinh ancestry.\n\n\nMETHODS\nIn a pilot study, 368 individuals (including 190 SCZ cases) were recruited at the Hanoi Medical University s associated psychiatric hospitals and outpatient facilities. Data collection included sociodemographic data, baseline clinical data, clinical interviews assessing symptom severity and genome-wide SNP genotyping. SCZ-PRS were generated using different training data sets: (i) European, (ii) East-Asian and (iii) trans-ancestry GWAS summary statistics from the latest SCZ GWAS meta-analysis.\n\n\nRESULTS\nSCZ-PRS significantly predicted case status in Vietnamese individuals using mixed-ancestry (R2 liability = 4.9%, p\u2009=\u20096.83\u2009×\u200910-8), East-Asian (R2 liability = 4.5%, p\u2009=\u20092.73\u2009×\u200910-7) and European (R2 liability = 3.8%, p\u2009=\u20091.79\u2009×\u200910-6) discovery samples.\n\n\nDISCUSSION\nOur results corroborate previous findings of reduced PRS predictive power across populations, highlighting the importance of ancestral diversity in GWA studies.