She knew that a member of her family carried the gene for it and realized she might have it too. And as well-off professionals, they can afford to brush off the incident as a minor bureaucratic irritation. But for many other would-be parents, the rapidly expanding availability of genetic tests to identify inherited ailments before or after birth often raises issues that are not so easily resolved. Beyond the poignantly personal dilemmas are broader family and societal issues. Indeed, the almost daily advances in our ability to forecast any of the 4,000 inherited diseases our genes might bequeath us have created such a thorny knot of private, ethical and social issues that the new genetic procedures are the subject of some 20 bills before Congress.
Testing is, of course, already commonplace.
As many as 9 out of 10 pregnant women in the U.S. submit to some prenatal screening. To look more closely at the baby's genetic prospects, doctors must probe the long stretches of DNA along the chromosomes constituting its genes. If you include testable variants of some diseases, such as the many different genetic mutations that can cause cystic fibrosis, the number of available DNA probes rises to some 400, with the count growing almost daily. Even more genetic gee-wizardry lies just down the road. In some systems, the probes use different fluorescent dyes that glow under laser light when they hook up with target genes, allowing sensors to tabulate the results automatically.