According to the DNA checked in this test, I am in the average risk range for type 2 diabetes. This doesn’t really seem to line up with my reality. But I might not expect it to since these genetic tests are so limited right now.
This kind of test can be informative with the yes answer—yes I carry a certain version of a gene that might lead to a disease. But the no answer isn’t that useful. It doesn’t mean that they've looked at all the possible genetic differences that can lead to a disease and I don’t have any of them. Basically it means that they didn’t find the specific genetic difference they were looking for.
Now I wouldn’t necessarily have predicted that any genetic test available right now could tell me a lot more than that. Type 2 diabetes is too complicated for that and a whole lot more research will need to be done to get a genetic test useful to lots of people.
But still, this is probably what people are looking for with these sorts of genetic tests. Will I get cancer, type 2 diabetes, Alzheimer’s, Parkinson’s, etc.? For most of these cases, the tests can tell you a lot about rare forms of these diseases but little about the more common forms.
So the no answer didn’t really help me much. Here I am on my way to being a diabetic and the test said I was at average risk. Of course, I suppose I didn’t even need to take a test… all four of my grandparents came down with type 2 diabetes. Like lots of these complex diseases, family history is the best predictor.
The second part of my question is a hypothetical one. Let’s say they had a perfect genetic test that said that I was at an increased risk for type 2 diabetes. Would it have changed my behavior? I’m not sure but probably not.
I certainly wouldn’t have changed any of my behaviors when I was young. I was invincible, remember?
Now that I’m a bit older, such a test might have influenced my behavior a bit. I already knew about my risk because of my grandparents but my thought has always been that maybe I got lucky and didn’t inherit their tendencies towards diabetes. But if they were tested and we shared the same genetic differences that led to type 2 diabetes, then I might be worried enough to change what I was doing.
Most likely though, my behavior modification wouldn’t be perfect. What I’d probably do is keep watching TV and eating Twinkies but get my blood sugar tested more often. Once I was headed for diabetes, then I’d modify my behavior and keep it at bay. (I’m sure doctors scream into their pillows at night because of patients like me.)
This is different than some people’s reactions to other genetic tests. For example, some women who find out they have the version of BRCA1 that greatly increases their chances of breast and ovarian cancer have a double mastectomy and/or a hysterectomy before there are any signs of cancer.
I might react much more strongly with a valid cancer genetic test. Cancer is scary, nasty and not really reversible. Type 2 diabetes is different. You can start down the road, modify your behavior and then nip it in the bud. Carpe diem and then pay the piper.