Retinitis pigmentosa (RP) is an inherited, degenerative eye disease that causes visual impairment and, eventually, blindness. RP is caused by mutations in the light-detecting photoreceptor rhodopsin.
Most RP patients have mutations in both copies of the rhodopsin gene (autosomal dominant); however, it is possible to carry only a single mutated copy (autosomal recessive). In the Journal of Clinical Investigation, researchers led by Kryzsztof Palczewski at Case Western Reserve University engineered mice with a single mutated copy of the rhodopsin gene and compared them to mice with two mutated copies.
The mice with a single mutated copy had delayed-onset, milder retinal degeneration. Additionally, they exhibited disorganized retinal structures and altered photoreceptor positioning. Interestingly, the mutant rhodopsin functioned normally, demonstrating that rhodopsin positioning was critical to its function.
This study demonstrates that positioning of rhodopsin in the retina is critical to its function and indicates that RP is caused by structural changes in the retina rather than a dysfunctional rhodopsin.
TITLE: Autosomal recessive retinitis pigmentosa E150K opsin mice exhibit photoreceptor disorganization