Ala Moshiri from the University of California is both a researcher and an eye doctor. He recently discussed his frustration surrounding the lack of available treatments for so many genetic eye diseases such as Stargardt disease, macular degeneration, and retinitis pigmentosa.
There are hundreds of genes that can cause blindness. However, there are probably many more that we have yet to uncover. Right now, just 50-75% of patients who are blind receive a diagnosis with genetic testing. For the others, the reason for their blindness is unknown.
Ala’s lab recently published a study in Communications Biology of all the genes which are necessary for normal function in the eyes. They found 347 genes which are necessary for proper vision. If any of these were mutated, the mice in their study became blind.
261 of the 347 genes had never previously been associated with blindness. This finding is important and could lead to improved treatments for many genetic eye diseases.
Ala’s lab used knockout technology to uncover these genes in mouse model. A knockout mouse means both copies of one gene is deleted in a mouse, deleting it from their genome. Due to the similarity of the mouse genome to that of humans, using mouse models can provide novel insights surrounding diseases which affect humans.
Knockout mouse technology was first developed in the 1990s. Thanks to this technology, researchers have created the International Mouse Phenotyping Consortium. This Consortium strives to include a mouse for every single gene within the genome. In total, 4,364 mice have been examined.
Ala and his team investigated these mice for their study. It is likely every gene they uncovered leads to eye diseases in humans. However, the next step to this investigation will need to be a human study of these genes.
The next step for Ala and his team is to establish a panel of the 261 genes and scan them for mutations.
They have also made the knockout mice publicly available as research models for other scientists. Interested researchers can order them from the IMPC repository. The hope is that others will use these models of mice to test potential treatments such as gene therapy or stem cell treatments.
Researchers will be able to cross-reference the 261 new genes with their human patients to uncover which gene mutation may have caused their blindness. Eventually, this new finding could lead to new treatments.
You can read more about this novel finding here.