ABCA4 and late-onset retinal degeneration: This allowed to cluster 41 patients into 4 subgroups, each with a phenotypic spectrum resembling 1) mitochondrial retinopathy (n = 10), 2) adult vitelliform or pattern dystrophy (n = 15), 3) late-onset retinal dystrophy (LORD) or Sorsby fundus dystrophy (n = 7) or 4), PRPH2- or ABCA4-associated retinopathy (n = 9).