The hereditary retinopathy, retinitis pigmentosa (RP), which affects 1 in 3,500 people worldwide, is the most common cause of registered visual handicap among those of the working age in developed countries. RP is a highly variable disorder where patients may develop symptomatic visual loss in early childhood, while others may remain asymptomatic until mid-adulthood. Most cases of RP segregate in autosomal dominant, recessive or X-linked recessive modes, with approximately 41 genes being i...