Should I have testing done

My son who is 6 was born with a abnormal hemoglobin which is a genetic blood disorder. So I guess what I'm asking is should I ask them to test when I do fall pregnant, it can cause a lot of heath problems basically he is missing a X crominzone even though it's heritery nobody else has it on either side if our families. The testing can cause a miscarriage but waiting Can cause life long blood transfusions or even death. So would you want to take the chance to carry the baby with no testing. Or do it ???? I really want another baby but I think this is a big mess any input on what you would do