Project Wonder - The art of science at the Medical College of Wisconsin

Could gene therapy treat color blindness?

What if a better genetic understanding of color vision could lead to a cure for color blindness? In 1995, scientists at MCW challenged the prevailing thought that three genes were responsible for color vision and that problems in one or more of these genes caused color blindness. Drs. Jay and Maureen Neitz, currently at the University of Washington School of Medicine, reported evidence in Science in 1995 showing that up to nine genes can produce cone photopigments in the retina that are sensitive to the colors red and green. Their team also found large variations in the number of color vision genes in an individual’s DNA blueprint as well as in the sequence of these genes.

Drs. Jay and Maureen Neitz detailed further findings in Science in 1996 regarding techniques that could predict the presence and severity of color blindness. Their team developed the Neitz Test of Color Vision as an easy and inexpensive method of screening children and adults for color blindness because this common condition today affects approximately 14.5 million people in the US.

Currently, there is no treatment for color blindness. Scientists in MCW’s Dennis P. Han, MD, Advanced Ocular Imaging Program are collaborating internationally on clinical trials that began in 2016 to test the use of gene therapies to treat achromatopsia, a less common and more severe form of color blindness and overall vision loss. Scientists leading these trials reported in 2022 in Brain that two treated pediatric participants had experienced improved cone function and cone-supported vision. The clinical trials continue and may lead to future opportunities to test the safety and effectiveness of gene therapies for other forms of color blindness. This may one day open up career paths currently closed to individuals whose genes change how they see and perceive some or all the colors of the rainbow.

Artwork by: Izamar Virafuentes