Although ABCA4 heterozygous variants have been widely reported in association with increased risk of age-related macular degeneration 2 (ARMD2, OMIM # 153800) in the literature32, and these patients are known to develop central retinal degeneration in older age, patients bearing monoallelic ABCA4 variants have been considered as “unsolved”. The gene discussed is ABCA4; the disease is age related macular degeneration 2.