Leveraging diverse genomic data to guide equitable carrier screening: Insights from gnomAD v.4.1.0.

Abstract

Analysis of exome data from the latest release of the Genome Aggregation Database (gnomAD v.4.1.0) revealed a significant carrier burden of pathogenic/likely pathogenic (P/LP) variants in genes associated with autosomal-recessive conditions across diverse ancestral populations. Carrier screening panels are routinely offered to reproductive partners to inform their risk of having an affected child. Current guidelines from the American College of Medical Genetics and Genomics (ACMG) recommend screening for genes with a carrier frequency of at least 1/200 and associated with moderate/severe conditions. Here, we systematically analyzed >700,000 gnomAD v.4.1.0 exomes spanning eight ancestries to estimate the carrier frequency of P/LP variants in 2,987 genes associated with autosomal-recessive conditions. After expert curation for clinical severity, we identified 286 genes meeting the criteria for carrier screening. The number of genes exceeding the 1/200 threshold varied across populations, with 40 in the South Asian ancestry and up to 119 in the Ashkenazi Jewish population. Simulations showed that pan-ethnic screening panels offer advantages for individuals of diverse or admixed ancestry, while ancestry-specific panels may be preferable for genetically homogeneous populations. This study leveraged the most comprehensive genomic dataset to date to provide an updated candidate gene list for equitable carrier screening across diverse populations. Our findings highlight the need for continued expansion of genomic resources to better understand rare disease risk and inform screening efforts in underrepresented groups.