advertisement
Abstract #19334 Published in IGR 9-3
Col4a1 mutation causes endoplasmic reticulum stress and genetically modifiable ocular dysgenesis
Gould DB; Marchant JK; Savinova OV; Smith RS; John SWMHuman Molecular Genetics 2007; 16: 798-807
Ocular anterior segment dysgenesis (ASD) is a complex and poorly understood group of conditions. A large proportion of individuals with ASD develop glaucoma, a leading cause of blindness resulting from retinal ganglion cell death. Optic nerve hypoplasia is thought to have distinct causes and is a leading cause of blindness in children. Here, we show that a mutation in the type IV collagen alpha 1 (Col4a1) gene can cause both ASD and optic nerve hypoplasia. COL4A1 is a major component of almost all basement membranes. The mutation results in non-secretion of the mutant COL4A1 proteins, which instead accumulate within cells. Basement membrane abnormalities may, therefore, contribute to the phenotype. The mutation also induces endoplasmic reticulum stress and so intracellular stress may contribute to pathogenesis. The overall consequence of the Col4a1 mutation depends on genetic context. In one genetic context, the mutation causes severe ASD with intraocular pressure abnormalities and optic nerve hypoplasia. In a different genetic context, both the ASD and optic nerve hypoplasia are rescued, and we have identified a single dominant locus that confers the phenotypic modification.
Dr. S.W.M. John, The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA. simon.john@jax.org
Classification:
9.1.3 Syndromes of Axenfeld, Rieger, Peters, aniridia (Part of: 9 Clinical forms of glaucomas > 9.1 Developmental glaucomas)
3.4.2 Gene studies (Part of: 3 Laboratory methods > 3.4 Molecular genetics)
