in bloomfield, new jersey, michael goodwin and his wife fazia are afraid to have children. he has sickle-cell, she is a carrier. michael goodwin: if i can prevent my kid from having to be up in pain and crying 24/7, i would do anything in my power to stop that. kristen: but critics worry crispr could be used to create designer babies, selecting hair or eye color, and some say there is potential for new mutations or even malicious uses. last year, former director of national intelligence james clapper called genome editing a potential weapon of mass destruction. and congress has banned turning gene-edited embryos into babies. in that lab in oregon, the embryos weren't allowed to develop more than a few days. but the debate over what they may have started lives on. kristen dahlgren, nbc news, new york. rosemary: scientists also say they've used the crispr technique to erase a gene that causes a type of heart disease that can lead to sudden death. now, according to the doctors at oregon health & science university, the gene editing did not alter dna in other ways. they also sa