Dear Dr. Stone,
I am 35 years old and was diagnosed with autosomal dominant retinitis pigmentosa when I was 26. I had a molecular test that discovered that the cause of my disease is a mutation in the RP1 gene. I have two children age 8 and 6. Can I have them tested to see if they inherited the retinitis pigmentosa gene from me?
Regards,
Anne
Dear Anne,
Thanks for your email. I completely understand your concern for your children and your interest in knowing whether they might be affected with the same condition that you have. However, I think that it would be best to examine your children clinically before considering a molecular test. If there is some clear evidence of a retinal problem on examination, I think that it would be reasonable to go ahead and confirm the diagnosis molecularly. However, when a minor child has absolutely no clinical evidence of disease and when there is no medical treatment that is known to delay or prevent the onset of the disease (as is the case for RP1-associated retinitis pigmentosa) we would generally avoid molecular testing until they are 18 years of age. At that time, they can choose whether they want to know their molecular diagnosis. Also at that time the molecular diagnosis will be a bit more relevant (they will be closer to child bearing age) and they will be in a better position to understand it. If between now and age 18 either of your children were to develop clinical signs of disease OR if some type of medical treatment became available for RP1-associated RP, this would make it more reasonable to go ahead and test your children even though they are minors. In summary, most geneticists would recommend NOT TESTING asymptomatic minors for the presence of a potentially-disease-causing genetic variation and this is the policy we follow in almost all cases. However, it is reasonable to have your children examined clinically and that is what I would propose as the proper next step for your family.
Regards,
Ed