Wednesday, May 9, 2012

Social Taboos Thwart Cures for Cystic Fibrosis, Tay-Sachs, Sickle-Cell Anemia and other Genetic Disorders

One of the most heartbreaking perils of parenthood is the discovery that one's newborn carries such genetic markers for premature death as Cystic Fibrosis, Sickle Cell Anemia, or Tay-Sachs Disease.  Life will always have risks. But the aforementioned disorders caused by the inheritance of matching recessive genes from both parents, may not have to be one of them, at least for future generations if not for present-day sufferers.  The reason is a concept called "genetic distance," which corresponds to some degree with the geographical distance between  diverse populations.  In short, the term refers to the familial closeness or distance of any two people, with the greater genetic distance signifying that the two will share fewer of the same disorder-triggering recessive genes.

Medical knowledge of recessive genes, the disorders caused by them, and the risks of inbreeding have been known for decades.    But what hasn't existed until now is the social freedom to choose one's spouse outside a narrow community of potential partners.   Given the rich tapestry of American society, drawing immigrants from all over the world, the twenty first century offers the potential for physical health and mental vigor beyond anything our society has yet known.  But we must first be willing to step outside our genetic  neighborhood.  Where the Nazis missed the boat was in believing that their ideology of racial inbreeding would lead to superior human beings.  Fortunately for their descendants, the Aryan experiment was brought to an abrupt halt with their World War II defeat. 

  In recent years, medical practitioners have increasingly used genetic tests to ferret out matched pairs of recessive genes in an embryo or fetus for the benefit of couples fearing that their children will inherit a recessive gene disorder.   But ruling out specific diseases is no guarantee that a couple will have a vigorously healthy child.  Those positive odds only rise, and they do so exponentially, when two people come together from populations that are geographically and genetically distant from one another.  In the meantime, researchers will continue to spend billions of dollars seeking better treatments for those suffering from genetic diseases, knowing that medical science is not even close to eradicating these disorders.  But carrying around a good map of the world when deciding on a date just might.