Apparently the gene can only be carried by females and passed on as the disorder to males for either disorder, so the fact that I've had three healthy sons means that future generations for me are free of the risk.

If I'd had a daughter I'd have had her checked out.

Cool, I didn't know if it carried a recessive gene, a lot of inherited disorder do. All you need is the chance meeting of two strangers with the recessive or a gene and a mate with a recessive to change the odds.

I've been doing some more research over the last bit of a while since this issue came up, and I've discovered that the understanding of both disorders is different now. In any case, we had the tests necessary anyway, but it's amazing how much more we (collective) learn in such a short time.