AP IMPACT: Testing curbs some genetic diseases
By MARILYNN MARCHIONE 2/17/2010
Report from the Associated Press: (Excerpts)
Some of mankind’s most devastating inherited diseases appear to be declining, and a few have nearly disappeared, because more people are using genetic testing to decide whether to have children.
Births of babies with cystic fibrosis, Tay-Sachs and other less familiar disorders seem to have dropped since testing came into wider use, The Associated Press found from interviews with numerous geneticists and other experts and a review of the limited research available.
Many of these diseases are little known and few statistics are kept. But their effects — ranging from blood disorders to muscle decline — can be disabling and often fatal during childhood.
Now, more women are being tested as part of routine prenatal care, and many end pregnancies when diseases are found. One study in California found that prenatal screening reduced by half the number of babies born with the severest form of cystic fibrosis because many parents chose abortion.
More couples with no family history of inherited diseases are getting tested before starting families to see if they carry mutations that put a baby at risk. And a growing number are screening embryos and using only those without problem genes.
The cost of testing is falling, and the number of companies offering it is rising. A 2008 federal law banning gene-based discrimination by insurers and employers has eased fears.
Genetic testing pushes hot-button issues: abortion, embryo destruction and worries about eugenics — selective breeding to rid a population of unwanted traits. Yet it is touching a growing number of people:
Although genetic testing can raise moral dilemmas, at least one conservative religious group — Orthodox Jews — has found ethically acceptable ways to use it to lessen diseases that have plagued its populations.
“I am a Holocaust survivor. I was born in the middle of the second World War. I hope that I am not a suspect for practicing eugenics. We are trying to have healthy children,” said Rabbi Josef Ekstein of New York, who founded a group that tests couples and discourages matches when both carry problem genes.
Lots of eyes are on cystic fibrosis, a disease that causes sticky mucus buildup in the lungs, digestive problems and death in young adulthood. More than 10 million Americans — one in 25 to 29 whites, who are more at risk for it than blacks — carry a gene mutation for it. In 2001, the American College of Obstetricians and Gynecologists and other groups recommended that white pregnant women be offered testing for mutations. Tests on partners and fetuses often followed, and an unknown number of abortions.
The impact showed up two years later in Massachusetts, one of the few states testing newborns for the disease at the time. Births of babies with cystic fibrosis dropped, from 29 in 2000 to only 10 in 2003, ticking up to 15 in 2006, said Dr. Richard Parad, a Brigham and Women’s Hospital physician who helped set up the screening program.
In California, Kaiser Permanente, a large health maintenance organization, offered prenatal screening. From 2006 through 2008, 87 couples with cystic fibrosis mutations agreed to have fetuses tested, and 23 were found to have the disease. Sixteen of the 17 fetuses projected to have the severest type of disease were aborted, as were four of the six fetuses projected to have less severe disease.
Gene testing hasn’t led to declines in all diseases. Sickle cell, a blood disorder that causes anemia and pain and raises the risk of stroke, has not dropped. It mostly afflicts blacks; gene carriers are said to have sickle cell “trait,” which sounds harmless.
Gene testing also has had little impact on Huntington’s disease, a progressive, fatal neurological disorder. Unlike many other inherited diseses, only one bad copy of a gene is needed to cause Hungtington’s, and symptoms don’t usually appear until middle age, after many have already had children.
Eliminating disease is a noble goal but also “should give us pause,” Lerner, the Columbia historian, wrote recently in the New England Journal of Medicine.
“If a society is so willing to screen aggressively to find these genes and then to potentially to have to abort the fetuses, what does that say about the value of the lives of those people living with the diseases?” he asked.
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