Natural History Study of Patients With X-linked Retinal Dystrophy Associated With Mutations in Retinitis Pigmentosa GTPase Regulator (RPGR)

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.

Primary outcomes

• Analysis of retinal structure and function to assess disease progression [6 years]: Retinal structure will be measured using Adaptive optics and SD-OCT and Fundal autofluorescence.

Secondary outcomes

• Retinal Sensitivity [6 years]: To be assessed by Microperimetry
• Retinal Structural detailed phenotyping [6 years]: Retinal Structure measured by Adaptive Optics (
• Fundus Autofluorescence [6 years]: Presence or Absence
• Visual Fields testing [6 years]: Assessment of Visual Fields with analysis of hill vision by perimetry

Sex: All, ages: 5 Years to any

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

• Michel Michaelides, Prof, Principal investigator, UCL/Moorfields