RP1 and hypoparathyroidism-retardation-dysmorphism syndrome: Recently, enrichment of the G843E variant in EYS in a group of patients with hereditary retinal degenerations (HRD) that carried a quasi-Mendelian allele in another gene (c.5797 C>T/p.R1933* in RP1), has been reported4, suggesting indeed a non-Mendelian, oligogenic or genetic modifier role of EYS in retinal degeneration.