Unveiling ocular developmental disorders through short-read whole-genome sequencing.

Congenital eye malformations represent a clinically and genetically heterogeneous group of disorders. Despite advances in genetic testing, fewer than half of affected patients receive a definitive molecular diagnosis. However, obtaining a molecular diagnosis is crucial for these patients and their families. Whole genome sequencing (WGS) is now standard practice in the genetic investigation of patients, but its contribution has not been extensively evaluated in patients with ocular malformations. In this work, we performed short-read WGS in a cohort of 100 families presenting with eye developmental disorders, including microphthalmia-anophthalmia spectrum (M/A), coloboma, anterior segment dysgenesis, congenital cataracts and/or foveal hypoplasia. Prior to WGS, 47 individuals had undergone targeted next-generation sequencing (NGS) of genes panels related to ocular development, 11 had chromosomal microarray analysis (CGH-array) and 20 had a combination of both. None had received a definitive genetic diagnosis. WGS identified a (likely) pathogenic variant in eighteen patients. In addition, candidate variants of uncertain significance were detected in nine patients. Notably, fourteen of these variants would have been missed by conventional genes panels or CGH-array, underscoring the broader diagnostic scope of WGS. Our findings demonstrate that short-read WGS significantly improves diagnostic yield in patients with congenital eye malformations, including those previously undiagnosed despite NGS panel testing. These results support the integration of WGS in the genetic evaluation of ocular developmental disorders.