enzymatically produces the retinol required for human vision

The protein, hRpe65 is the enzyme found in the eye that produces retinol, a small molecule required for regeneration of the photo-sensitive pigment in photoreceptor cells.

Mutations that cause the hRpe65 to either misfold or be unable to bind the iron cofactor are associated with retinitis pigmentosa and Leber’s congenital amaurosis.

To treat these conditions an adenovirus is cleared of its normal viral payload and instead loaded with the DNA that encodes for the wild-type protein, hRpe65 . The engineered virus is then introduced to the eye, and instead of creating more viral proteins, directs the cells in the eye to produce the well-formed enzyme. Once the enzyme is being produced in the retinal cells, they become able to produce the useful version of retinol and vision is restored.


  • Spark produces a gene therapy to cure RPE65-mediated inherited retinal disease



[1]: Bennicelli et al. 2008
[2]: Bennet et al. 2017