Single Gene Controls Brain, Lens, Retina Development

Researchers at St. Jude’s Children’s Research Hospital are expanding their understanding of how a key gene, designated Six3, regulates the development of the eye as well as the cerebrum. Several years ago, a related team of researchers at St. Jude’s showed that if the Six3 gene is defective, it leads to a failure of the cerebrum to divide properly into two lobes, a condition known as holopresencephaly. Because the eye normally grows out of the brain in normal fetal development, its connection with eye growth is normal, but just how much it controls the eye continues to be revealed.

The first portion of eye development shown to be linked to the Six3 gene is the development of the lens. The Six3 gene activates another gene, known as the Pax6, which controls several other genes that work together to create the lens. Now researchers have linked the Six3 gene to retinal development. When the Six3 gene is expressed in the retina, it blocks another protein, which has the power to stop the development of the retina, although the exact mechanism by which that blocking occurs is unknown.

The hope is that understanding the process of retinal development will allow for future gene therapy that can replace retinal and optic nerve cells lost to conditions like age-related macular degeneration and glaucoma. The current line of research represents the most recent in a number of promising avenues for gene therapy to counteract common vision problems.

Currently, glaucoma and age-related macular degeneration are two of the more significant threats to vision faced by older Americans. Glaucoma has no symptoms and few signs before vision loss occurs. Once diagnosed, glaucoma treatment can be effective, but currently there is no way to reverse damage to the retina and optic nerve. Therefore, people are encouraged to get regular glaucoma screenings to avoid this “silent thief of sight.” Currently, no treatments are available that can stop or reverse the progression of age-related macular degeneration.

To schedule your glaucoma screening and learn about the best treatment options available today, please contact a local ophthalmologist today.