Expanded carrier screening in a Southwestern Chinese population indicates East Asian specific low-frequency pathogenic variants account for nearly half of the at-risk couple rate

East Asian-specific low-frequency pathogenic variants contributing to half the at-risk couple rate

A 334-gene expanded carrier screening panel was applied to 3,748 individuals from Sichuan, China. 65.55% of participants carried at least one pathogenic/likely pathogenic variant, and 83 couples were at risk (5.19%), including 55 for autosomal recessive conditions. Among 46 low-frequency variants (MAF ≥0.1%), 54% were East Asian-specific and contributed 41.8% of AR at-risk couples, versus 9.1% for globally shared alleles. Three regionally enriched variants (HBB, GJB2, SLC25A13) alone contributed 20% of the rate. The authors conclude that screening panels should prioritize population-specific carrier frequencies.

Synthesis written by Geno'X. For the full original abstract, please refer to the source publication.

The argument is robust and transferable: the composition of a carrier screening panel must reflect the target population rather than global frequencies often dominated by European cohorts. This is relevant for France, whose diversity of origins calls for reflection on coverage of population-specific variants. A well-conducted descriptive study, without methodological novelty but with a strong screening-policy message.