To determine (1) clinical features that distinguish maculopathy due to the R345W substitution in fibulin-3 from other forms of inherited or early-onset drusen, (2) the phenotypic variability, and (3) the extent of retinal disease in those with a positive molecular diagnosis.
The Arg345Trp mutation on exon 10 of the EGF-containing fibulin-like extracellular matrix protein 1 (EFEMP1) gene causes two clinical phenotypes of early onset drusen (Doyne honeycomb retinal dystrophy and Malattia Leventinese), yet does not appear to be involved in other early onset drusen phenotypes or typical AMD.
The Arg345Trp disease-associated allele of the EFEMP1 gene does not appear to be associated with cases of early onset drusen that fall outside the diagnosis of malattia leventinese or Doyne honeycomb retinal dystrophy, nor does it appear to play a role in familial age-related macular degeneration.