The rod-cone dystrophies (often referred to as retinitis pigmentosa (RP)) are a clinically and genetically heterogeneous group of disorders in which there is progressive loss of rod and later cone photoreceptor function leading to severe visual impairment. RP usually occurs as an isolated retinal disorder, but it may also be seen in association with systemic abnormalities.

X-linked Retinitis Pigmentosa (XLRP) is a severe form of RP with early onset of nyctalopia and progression to legal blindness by the 3rd to 4th decade. Most affected males show symptomatic night blindness before the age of 10 years, are often myopic and show fundus abnormalities and ERG changes in early childhood. Examination of close female relatives is helpful in the absence of a family history, as the recognition of the XL carrier state will confirm the diagnosis.

Inclusion Criteria:

• Males & Females aged 5 years or older
• Have RPGR-associated retinal dystrophy
• Are able to give informed consent or assent, with the guidance of their parent/guardian where appropriate
• Are able to undertake age-appropriate clinical assessments as specified in the protocol
• Have genetic mutation within the RPGR gene confirmed by an accredited lab or research lab.

Exclusion Criteria:

• Are unable or unwilling to undertake consent or clinical testing

Patients with RPGR-associated retinal dystrophy