GNAT1 and retinitis pigmentosa 1: Two cases in the recessive/simplex RP cohort were particularly noteworthy: A homozygous premature stop mutation in the GNAT1 gene (NM_000172.3:c.904C > T,p.Gln302*) in a case of simplex RP, which has been reported in an earlier paper23 and a homozygous frameshift in the SLC24A1 gene (NM_004727.2:c.2679delT,p.Asn893fs) in a pedigree with two affected individuals.