So, Tim here (Lauren’s husband, not Libbie’s, who is also named Tim, just because we want to confuse you…). As Lauren indicated in her previous post, after we found out about her kidney I started really thinking there must be a common genetic defect causing her various problems. So I did some research, Googling with search terms like ‘tetralogy fallot missing kidney’ to see if this was an issue for other people. It didn’t take long to figure out that there were several syndromes that included both malformed heart and kidney as possible symptoms, and in fact all of these syndromes (Shprintzen, DiGeorge, Velocardiofacial Syndrome, etc.) actually turned out to be different manifestations of the same underlying genetic problem: 22q11.2 deletion syndrome: http://en.wikipedia.org/wiki/DiGeorge_syndrome
Essentially, it means that a portion of the 22nd chromosome is missing. One whole chromosome is received from one parent, while a partial (mutated) one is received from the other. There are about 180 different possible symptoms or manifestations of this condition, so the effects vary pretty widely from individual to individual. In Lauren’s case, it’s mainly the cardiopulmonary, renal and immune systems affected, with some other minor things thrown in. The deletion itself is relatively common as genetic diseases go (1 in 4,000), outnumbered only by Down Syndrome, I think; however, Lauren’s particular combination of symptoms (and other issues related to surgeries) is quite rare.
Anyway, as I read more about it, I became certain that Lauren had the deletion. Once we knew the disease we were looking for, it was just a matter of getting her tested, which was easier said than done. After a lot of back-and-forth with doctors we finally got a referral to a geneticist, who was 95% certain of Lauren’s 22q deletion just after meeting & talking with her — there are distinctive facial characteristics involved, more on that in another post — and she confirmed it with a genetic test (called a FISH test).
I had previously inquired what chance Lauren had of passing on her heart problems to any children, and her cardiologist had told me that the typical rate was about 3% for people with congenital defects. Learning that 22q was the issues increases this to a whopping 50%; Lauren had already undergone a hysterectomy by that time, though, so it was no longer an issue.
I do think that the problem should have been caught before; I shouldn’t have had to diagnose her myself, at the age of 25. Apparently the relevant type of genetic screening was in its infancy when she was born, but it should have been performed at some later time. It’s now pretty standard for babies with congenital defects.
Although 22q can be passed down from the parents, neither of Lauren’s appears to have it, meaning that it was a ‘spontaneous mutation.’ For some reason, she does not appreciate it when I call her a “mutant,” even though she could theoretically develop superpowers and join the X-Men, which I think we can all agree would be awesome.