Whole-genome sequencing uncovers diverse genetic causes and phenotypic signatures in infantile nystagmus and albinism.

We combined deep phenotype data and whole-genome sequencing results from the UK 100,000 Genomes Project (100KGP) to characterize the genetic spectrum of infantile nystagmus and albinism, and to explore genotype-phenotype correlations in this cohort. Participants were enrolled in the study based on the clinical codes for albinism or infantile nystagmus. Whole genome sequencing data was retrieved and variants in known nystagmus/albinism genes (PanelApp R39 panel) were analysed alongside genome-wide findings. We ascertained 473 affected individuals (388 families). Positive genetic findings were obtained in 218 participants (46%), including 176 (37%) with definitive diagnoses. Pathogenic variants were found in 16 of 38 panel genes, most commonly in TYR (56 families) and OCA2 (21 families). Recurrent variants (24% of 103 different variants) were identified in six genes. An additional 36 off-panel genes accounted for diagnoses in 45 families, including four dual genetic diagnoses in three families. Phenotypically, refractive errors and foveal hypoplasia-related diagnoses were significantly enriched (odds ratio ~2.8 for refractive disorders). Strabismus and neurodevelopmental features were also over-represented in the cohort. We show that whole-genome sequencing provided a high diagnostic yield in infantile nystagmus/albinism and uncovered a broad allelic spectrum. Integrating comprehensive phenotype data identified distinct genotype-phenotype relationships.