Retinitis is caused by an autosomal dominant, recessive or via x-linked mutation in the gene. There are a variety of point mutations, which can cause retinitis pigmentosa causing a base change and therefore changes in the amino acid sequence.
Furthermore, this, in turn, damages the rods and cones of the photoreceptors in the eye. This may enhance the damage to the sight and also reduce the function for the rhodopsin to be activated by light.
The disease of retinitis pigmentosa may be cured by eating food which is rich in Vitamin A, this recover the eyes to be functional in terms of getting the inside rhodopsin and other protein kinase to do the cycles.