Its expedient that couples undergo genotype test before marriage, in fact i recommend it before things start getting heat up, this way, when push come to shove you will move on without feeling too bad. Its not the couples life that is on the line here, but that of the innocent child, i have a nephew who is a sicker, man the experience is real baaaaaaaaaaaad, so please if you meet a guy or lady today, go for a gen test tomorrow. Its that serious. :'(