Then, one of these 8 cells is taken out of each of the embryos and tested for the gene. Those embryos that do not have the Huntington's gene are then implanted. There are lots of questions about this procedure from an ethical standpoint. It is also very expensive. Then we have, of course, the ethical issues of insurability and health care for individuals who are carrying a disease gene.
Presymptomatic testing is now available for a variety of human genetic diseases.
This means that for those individuals who are at risk of developing a hereditary disorder, a test is available which will tell them if they carry the disease gene or not. Individuals who choose to undergo this testing can find out whether or not they are going to develop a particular disease years in advance of the onset of their symptoms. A major concern we have is that discrimination will occur for individuals who carry genes for severe late-onset disorders. We all carry bad genes, and we're very fortunate that most of them are recessive. None of us is perfect from a genetic point of view, and it is unfortunate that discrimination occurs against those whose genetic endowment has led them to develop a disease like Huntington's.