Well I think that if some have kids, they could eventually be 'mutations', having similar powers but the effects are different and such. 

If we speak of passing on genes, there would probably be more chances of having a child that's a mutant by having both parents like experiments than a single parent being a freak and the other normal. There's also a chance they make a normal kid. 

My character isn't developed enough to make children, so she can't naturally pass on her genetic disease and the immortality that naturally comes with it, let alone her powers.