So far, researchers have found at least seven mutations that cause the disease. Once the gene has been screened thoroughly for mutations, genetic testing for this X-linked RP gene will be possible. Females who carry the X-linked gene have a 50 per cent chance of passing the gene to their children. Genetic testing will enable clinicians to identify female carriers and affected males. Researchers are also studying the RPGR gene to understand how it causes retinal degeneration.
Every gene produces a unique protein that serves a specific function in a cell.
Genetic mutations cause disease by producing abnormal proteins that cannot function properly. The RPGR gene is a somewhat unique RP gene in that it makes a protein found in cells throughout the body, not just in the retinal cells. The structure of this protein suggests it may activate some function of special importance to the retina. Once the function of the RPGR's protein is understood, scientists can learn how the mutant version of the protein damages retinal cells. The discovery of the RPGR gene is particularly promising as it paves the way for future research avenues that could not progress until an X-linked RP gene was isolated.