Sorry Poll, but I reckon if you want proper answers, genetic testing is the way forward.
Maybe I'm over-simplifying, and it can't give definite answers? But if it can, beats me why it wasn't done ages ago, instead of all this faffing.
Why are you worried about the cost? You wouldn't be expected to pay, would you?
If I remember rightly, you were a bit reluctant to have tests that might prove it was HSP, because of the implications for your children?
But I think you're at the point now, where you have either to accept you might learn something you'd rather not know, OR put up with the uncertainty forever.
I'm sorry if I'm reading the situation all wrong. But that's how it looks to me: that you want an answer, but not if it would be the "wrong" one.
I do understand that, but on the bright side, it might show that it is definitely NOT HSP, in which case you could stop worrying about inheritance. Maybe it has been MS all along?
I think it all comes down to how much you really want/need the answer, even if it could have serious implications for the rest of the family. If you decide not knowing is better than hearing something bad, then don't have the test.
But if you want certainty at last, I don't think skipping the test will give you that.
Is there any counselling or anything offered with this test? I would have thought, usually, with genetic testing, there should be counselling about all the pros & cons of knowing versus not knowing, before you decide.
What do other members of the family think? They must know by now there's a possibility it's an inherited disease? Would they rather not know, and leave it up to Fate, or do they want and need answers, too?
If the test were positive, would they also be offered testing, and would they accept? How likely is it that you would have passed it on? Would there be any advantage to them of knowing? I.e. can anything be done about it, if it were caught sooner than it was with you?