The purpose of this study is to evaluate subjects with X-linked retinitis pigmentosa caused by RPGR-ORF15 mutations in a clinical setting to fully characterize their condition, measure testing variability, and estimate rates of progression of clinical parameters.

Males with a clinical diagnosis of X-linked retinitis pigmentosa (XLRP) caused by RPGR-ORF15 mutations will be asked to provide informed consent and will have a single blood or saliva sample obtained for DNA sequence analysis of genes known to cause XLRP, including the RPGR-ORF15 gene. All participants will be informed of the results of testing for these mutations. Those with qualifying mutations in the RPGR-ORF15 gene will be evaluated every 6 months for 3 years using a variety of non-invasive visual function tests to more fully characterize their clinical condition. Testing will include routine ophthalmic examinations and tests of visual acuity, perimetry, OCT, fundus imaging, and completion of quality of life questionnaires.

Inclusion Criteria:

• Male subjects with a clinical diagnosis of XLRP and a documented molecular diagnosis from a CLIA-certified laboratory of mutation within the ORF15 exon of the RPGR gene;
• At least 6 years of age;
• Willing and able to perform study procedures;
• Signed informed consent(s) obtained (and child assent where applicable).

Exclusion Criteria:

• Pre-existing eye conditions that would interfere with interpretation of study endpoints (e.g. glaucoma, corneal or lenticular opacities, diabetic retinopathy, history of retinal detachment);
• Participating in an interventional research study of drugs or devices for treatment of XLRP or other retinal diseases;
• Monoocular participants
• Any condition which leads the investigator to believe that the participant cannot comply with the protocol requirements or that may place the participant at an unacceptable risk for participation.

Males with a clinical diagnosis of X-linked Retinitis Pigmentosa (XLRP)