Boston.-- SO, ANOTHER pair of genes has been discovered in our biological closet. It happens regularly these days. A group of scientists goes mucking about in the private corner of our DNA and comes out with something new.
This time, Boston researchers have uncovered a mutant gene. The mutant P53 can produce cancers that ''run in families'' like a train crashing over the generational track.
In one of the 80 families they studied with the rare Li-Fraumani syndrome, seven of 13 members had cancer at a young age. Many relatives had experienced so much of the disease that it was considered a family curse. Indeed, people in families who carry this defect have a 50 percent chance of cancer by age 30 -- and now they can know the odds at birth.
The study reported in Science magazine may be the first such documented genetic cancer link, but it's not the last. Nor is this cancer link the most the devastating of the genetic discoveries.
We already know the genes for Huntington's chorea and sickle-cell anemia, for cystic fibrosis and muscular dystrophy. We are learning what makes some susceptible to aneurysms and may learn what makes others prone to alcoholism.
The Human Genome Project, set up to map chromosomes over an internal human space as vast as any universe, will seek out some 100,000 genes stretched out over the DNA. But there will be a ''lag'' between the knowledge and the cures. We are discovering diseases faster than we can fix them.
What will happen as scientists learn what ''runs in families?'' Those families will have to decide what they want to know, and what they want others to know. As we learn about genetic susceptibilities, we will all have to think about the nature of risk. And as we delve into DNA, we will have to reconcile the idea of equality with the facts of biological inequality.
Genetics is going to change the nature of our health-conscious society. Today, after all, we prefer to pin illness on human behavior. We talk of risk behaviors and risk factors. It's comforting to look for the smoker in the heart-attack victim, to search for the fat in the diet of the deceased. Our second-most popular culprit for illness is the environment. We are obsessed with risks that range from asbestos to Alar, from dioxin to Equal.
But these risks are the ones we share. We are all presumably at danger from the environment; we're all able to alter our behavior. If you are what you eat, after all, you can change your diet.
What happens as we discover that some of us are more susceptible from birth than others? Some at greater risk, biologically, to certain diseases and certain environments, even work environments? What happens when we add genetic risk to the list?
When doctors take a family history, that history isn't always assumed to be destiny. But when family membership itself becomes a factor, will this create another social division?
Today, it often seems that race, religion, ethnicity and gender compete with the ideology of the melting pot. In many ways, talk of diversity is challenging the traditional language of equality.
Could biology exaggerate this? Could it create another class -- a biological underclass, uninsurable, unemployable. The Joneses have a mutant P53. Nice people, but you wouldn't want your daughter to marry one.
If this sounds like a dark outpouring of science anxiety, let me lighten it. The genie and the gene are out of the bottle. The possibilities of the research are stunning. Moreover, this time scientists are studying ethics along with genetics. For once, they aren't leaving social concerns to a mop-up crew.
But as Eric Juengst, a director-philosopher with the Human Genome Project, recognizes: ''The challenge is how to protect our commitment to social and moral equality in face of the fact that we are biologically diverse and, against some parameters, unequal.''
Americans have long wrestled with differences and democracy. On the one hand, people have uneven abilities; on the other hand, we are all equals.
Now we are facing a biological variation on that theme. In a country based on the notion that all people are created equal, scientists are uncovering our designer genes. They are not always a comfortable fit.