Routine testing identified a pathogenic missense variant in SNRNP200 (NM_014014.3: c.2042G>A, p.(Arg681His)), accounting for a diagnosis of autosomal dominant retinitis pigmentosa for this individual, with no pathogenic/likely pathogenic variants identified in-trans to the confirmed heterozygous deletion of IDH3B and MKKS. Of the 25 CNVs that enabled the confirmation or provisional confirmation of diagnosis, 23 confirmed autosomal recessive disorders and 2 confirmed autosomal dominant disorders (online supplemetary table S5). This evidence concerns the gene MKKS and autosomal dominant retinitis pigmentosa.