Homozygosity for a novel complex allele G1961E/L857P causes a childhood-onset cone-rod dystrophy rather than the young-adult-onset macular dystrophy that is associated with G1961E alone.
Three patients had a Gly1961Glu missense mutation, the most common variant in Stargardt disease (STGD), with 2 of these subjects having a macular dystrophy (MD) phenotype and a second ABCA4 variant previously associated with STGD.