29th December 2023

Background

Retinitis Pigmentosa (RP) encompasses a heterogeneous group of progressive inherited rod-cone dystrophies (i.e. principally affects rod photoreceptor cells) with a variety of inheritance patterns and mutations. Over 40 genes have been associated with RP.

Autosomal dominant forms (20-25%) are the most common and have the best prognosis, and typically involve mutations in the rhodopsin gene. Autosomal recessive cases (15-20%) include mutations in RP1. X-linked cases (10-15%) are the least common and often have the worst prognosis; they are most commonly due to RPGR mutations (70%) and may result in complete blindness by the third or fourth decade of life. A large proportion of RP cases (40-50%) are unsolved and may either be sporadic or related to an as yet undiscovered genetic mutation.