Rare heterozygous missense variants in VSX2 are associated with retinal detachment

Retinal detachment (RD) is a sight-threatening emergency requiring urgent intervention to prevent permanent vision loss. While both environmental and genetic risk factors contribute to RD, its complete genetic architecture remains unknown. Here, we performed the largest whole genome sequencing-based case-control study in RD to date, including data from 7,276 RD cases and 236,741 controls in the UK Biobank. Through variant- and gene-level association analyses, we identified VSX2 as a genetic determinant of RD risk while confirming established associations including FAT3, RDH5, and COL2A1. Gene-level collapsing analysis revealed that rare heterozygous missense variants in VSX2 confer a 2.8-fold increased risk of RD (p = 2.4x10-10; odds ratio (OR) = 2.8; 95% confidence interval (CI): [2.1, 3.7]). One missense variant in this gene, p.Glu218Asp, demonstrated a particularly strong effect size (p = 9.3x10-10; OR = 5.9; 95% CI: [3.7, 9.4]). Replication analyses in two additional cohorts, totaling 1,331 cases and 52,355 controls strengthened both the gene- and variant-level associations even further (p = 1.4x10-10 and 1.1x10-11, respectively). Other contributory heterozygous variants included previously reported pathogenic homozygous variants for anophthalmia and microphthalmia. These findings thus reveal a previously unknown gene dosage curve for VSX2, where homozygous mutations cause severe developmental eye disorders and heterozygous mutations cause adult-onset retinal detachment. Extending this observation, we found a significant enrichment for other known recessive Mendelian eye disease genes among nominally significant (p < 0.05) genes associated with RD in the collapsing analysis. This work provides a compelling example of how heterozygous variants in recessive disease genes can be associated with less severe clinical phenotypes.