Wednesday December 20, 2006

I was diagnosed some years ago with hypertrophic cardiomyopathy (HCM) and have recently been exploring whether it makes sense to have a genetic test done to identify my particular mutation to assess the particular risk factors associated with my flavor of HCM.

As it turns out, while there is a test available, it has a significant false negative rate. Meaning there is about a 40% chance that this test will not find a mutation in a patient with a clinical diagnosis of HCM. This is due mostly to the test covering only eight of the eleven sarcomere genes known to have mutations related to HCM. Some mutations will fall into the untested three genes and others presumably may fall on genes not yet identified.

The real problem is that there is not enough historical data to allow a patient to map their particular identified mutation to a risk level for things like sudden cardiac death. Which means the test isn't yet useful for answering my original question. But there are other reasons why this test might be interesting.

The test can be used to establish a screening mechanism for all of the descendants in my family. In particular, my nieces and nephews are all now being tested periodically via echocardiogram for clinical signs of HCM. So far, some have it and some don't seem to. A genetic test would give a definitive answer to the question.

All of this is fairly expensive. The initial testing, which needs only be done on one member of the family, costs about $4000. If a mutation is identified, then subsequent tests of other family members cost about $250 to determine if they carry the same mutation.

The insurance ramifactions of this are unclear at this point. Genetic testing for HCM will allow us to determine at a very early age (including ages less than zero since prenatal testing is available as well) and, presumably, far earlier than clinical signs might be detectable, whether a child has an HCM-related mutation. Does this constitute knowledge of the dreaded pre-existing condition that affects insurability? I suppose it does.

As genetic testing comes of age, it is easy to see that at some point in the not-too-distant future genetic testing will provide a very detailed accounting of the inherited problems to be faced by a child throughout its life. At that point it's likely that virtually everyone will have at least one identified pre-existing condition lurking somewhere in their genome. That's a sobering thought.

While I'm sure the insurance industry is busy ensuring they continue their profitable existence into this genetic future, I hope someone on the side of the insured is looking at this as well.