Introduction to theGenetics ofRetinitis PigmentosaKimberly J. Guthrie, MS CGCCertified Genetic CounselorMayo ClinicJacksonville, FL
Background Between 1 in 3500 and 1 in 4000 individuals in the United States will develop RP RP can be isolated or associated with other medical issues as part of a genetic syndrome
Inheritance Taking a family history can help determine the inheritance pattern and the risk to children and other family members RP can be inherited in different ways – Autosomal dominant – Autosomal recessive – X-linked
Genetics of RP At least 35 different genes have been found to cause isolated RP Genetic testing is informed by inheritance patterns Testing panels that test multiple genes at once are available
Benefits of GeneticTesting for RP Knowledge of the underlying cause Determine eligibility for clinical trials Clarify recurrence risks If the mutation in the gene is identified in an individual, multiple prenatal diagnostic options would be available
What to Expect: TheFirst Genetic CounselingVisit Review of medical records including eye doctor’s records Drawing out and interpreting the family history Discussion of genetic testing options including the benefits and limitations of genetic testing Answer any questions you may have
What Happens if I haveGenetic Testing Usually you will have your blood drawn for testing – For this type of testing it doesn’t matter if you have eaten or not – Often we first test the person with a diagnosis of RP and discuss testing other relatives after test results are available Results are typically available within one to two months
What to Expect: ResultsDiscussion If a mutation is found, the discussion will include: – Information about that gene – Risks to future children and other family members – Discussion of clinical trials or research studies available – Answering any questions you may have
What to Expect: ResultsDiscussion If no mutation is found, the discussion will include: – Review of limitations of testing – Discussion of whether additional testing may be of benefit – Making a plan for follow-up – Answering any questions you may have
For More Information Genetics Home Reference – http://ghr.nlm.nih.gov/condition/retinitis -pigmentosa GeneReviews: Retinitis Pigmentosa Overview – http://www.ncbi.nlm.nih.gov/books/NBK1417/
To Schedule anAppointment To schedule a Genetic Counseling appointment at the Mayo Clinic in Jacksonville, FL Call (904) 953-2272
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