krantz and hiwife, nancy, and their thr children -- >> i have to say that neither nancy or i or anyone in our family has had their genome sequenced yet, and not because we wouldn't be interested, but i don't think we really subscribe to the recreational sequencing of genomes, but if there was a medical concern, i don't think we would hesitate. >> reporter: for kathleen, even though the news about liam was not good, just knowing seems to have made a huge difference. >> i guess a miracle, i would say, because i waited so long, and as he was getting sicker i didn't want him to pass away, because then i would feel so guilty that i didn't do everything i could ve. now that i have a name, i know there's no cure for him, but he can help so many other kids. >> reporter: it's the promise of help for kids like liam that drives the science that is going so fast the road map with guidelines and warning signs can't keep up. and as the technology progresses, the ethical issues will become even more difficult. for "religion & ethics newsweekly," i'm lucky severson in west chester, pennsylvania. >>> a