It is increasingly recognized that the molecular landscape of ABCA4-retinopathy is complex, where disease penetrance and severity is dependent on the specific combination of variants acting in cis and in trans. 23This is typified by the hypomorphic p.(Asn1868Ile) variant, which was the fourth most encountered ABCA4 variant (Table 3) and the sixth most frequent IRD-associated variant overall in our study cohort (Table 8). Here, ABCA4 is linked to retinal disorder.