Four were normal, two were carriers, and diagnosis was unclear for one embryo. Three disease-free embryos were implanted, and the woman gave birth to healthy twins after 39 weeks of pregnancy. Genetic test of embryos still experimental. Xu and his colleagues at Cornell University in New York stressed that the PGD test was still experimental in looking for single gene defects, such as sickle cell disease. But with further refinement, researchers said, it will become a powerful diagnostic tool.
Tests already exist to check a fetus for sickle cell during pregnancy.
But some couples have strong personal objections to abortion when a pregnancy is already established. Pre-implantation genetic diagnosis could provide couples with another way to avoid passing on sickle cell disease. When both parents are carriers, they face a 25 percent chance of having a child with the disease, and half of their children may carry the gene. Sickle cell is a blood disorder that affects people of African heritage and several other ethnic groups from around the Mediterranean region. Cost may be an issue.