FBN1 and Marfan syndrome: In addition to identifying a novel mutation and broadening the spectrum of ocular phenotypes in Marfan syndrome, our findings suggest that pigmentary glaucoma may be another disease caused by mutations in FBN1. The abundant expression of fibrillin-1 protein in the iris and aqueous humor outflow pathway offer mechanistic explanations for both the unusual backward bowing configuration of the iris and a possible component of reduced outflow facility.