Being a carrier of genes is less worse a problem than carrying bad middos. If the guy has a good heart, and a clear torah head, then yes I would marry them. Life is short, chances of cropping up a kid with genetic deficiencies are slimmer than not. Hashem is in charge. You just pray”
You are comparing apples with toothpaste (not even with oranges). What have good middos to do with bad genes??? It’s not an either or situation. If someone is a carrier, he or she should NOT marry and reproduce with another carrier, because, depending on the gene they carry, they are gambling with every pregnancy. And though THEY might feel it is perfectly ok to trust in Hashem (as do I), that does not mean that if you step into empty space, you’re gonna fly. Hashem CAN and DOES do miracles every day all day. But most of us are not worthy to see a miracle of the magnitude that one would require to save the life of a baby born with Tay-Sachs, Disautonomia, etc. These are ALL preventable diseases, simply by not being meshadeich two people who carry that gene. It is not fair to the unborn children, to say Gott Vet Helfen. I would marry a carrier, but only if I were not also one, and only if it required genes from both parents in order for there to be a 25% risk (which is too high in my book) that the child would be born diseased. BTW, with what is going on nowadays with gene therapy, that will BE”H eliminate these issues, some day.