I've been asked a few times about genetics, and testing and such, and I read a great "booklet" today, by the PKD Foundation, that explained these things very well, so thought I'd share. I'll color the quotes.
Also, I forgot to say earlier, when I saw the urologist, he did a kidney function test and told me my kidney function was still excellent, even better than his own.. ha. So that was great news.
-People have asked how you're tested for PKD, if I'll have my kids tested, or if my family can just have their blood tested somehow, here's the answer:
"Ultrasound and CT scan are the most practical screening tests for ADPKD. Genetic testing of a patient’s DNA is available. This testing scans the
individual’s DNA isolated from a blood sample and looks for mutations in the PKD gene.
However, this test is extremely expensive and mutations are found in only 60 – 70 percent of
samples again giving us a high false-negative rate."
"The limitations of all these methods are that the cysts have to be large enough to be seen. Many
patients, particularly those with ADPKD2, do not have cysts large enough to seen until they are 30 years of age or older."
-Since we're unsure which of my parents have/had the PKD gene (not that it matters), people have said, maybe neither of them had it, or maybe they were just carriers. This answers that question:
"The gene for ADPKD is dominant, which means there only has to be one copy of the gene
passed on from either an affected mother or father to cause the disease. There is no carrier state
with a dominant gene – it does not hide and come out in a later generation. So, if a person has
the gene, at sometime in his/her life at least some of the symptoms of the disease will occur.
However, that does not mean that everyone who gets the ADPKD gene has the same signs or
symptoms, the same age of onset, or the same course of the disease. In fact, there is a wide
spectrum of severity with ADPKD. At one end are children who are diagnosed before birth or in
the first year of life with cysts and/or big kidneys, and at the other end is the person who has few, if any symptoms even when they are very old. Most people who have the ADPKD gene fall in the middle and at some time will have some of the signs or symptoms associated with ADPKD."
"There is a high probability that many people with a very mild
form of ADPKD are unaware of their status and thus are never diagnosed."