Family History a Warning for Fetus Health
Prenatal questionnaire can help identify the risks
SATURDAY, Dec. 15, 2001 (HealthDayNews) -- Combining medical histories of parents-to-be and their relatives with the latest in genetic research can help assess the risk of birth defects for an unborn child.
Identifying such risks early on will hopefully lead to better infant care and, as research continues, even cures for birth defects, a neonatal expert says.
"We are trying to harness the power of the human genome [project] for the benefit of families and their babies," says Dr. F. Sessions Cole, the director of newborn medicine at St. Louis Children's Hospital. "As the human genome project becomes a bit more mature, [it will hopefully] lead to cures."
Cole has developed a prenatal family history sheet for couples and their closest relatives, which "provides an opportunity for families and doctors to talk intelligently about what their risks are and introduce topics they don't automatically ask about," he says.
The questionnaire has been filled out by about 100 families at St. Louis Children's Hospital in the last year, Cole says. It asks for details about ethnic background, known birth defects in the family, miscarriages, premature births, stillborn births, early newborn deaths, low-birthweight babies or infections of newborns. It also asks for any information about mental retardation, slow development or other conditions that could cause concern.
The questions are designed to identify the risks for various genetic defects associated with certain groups of people. These risks can lead to illnesses like Tay-Sachs disease or sickle cell anemia. The questionnaire also aims to compile information on family patterns that might point to previously unknown risks for a couple's unborn baby.
Taking prenatal histories isn't a new idea, scientists say. But continuing advances in medicine now allow doctors to take better advantage of the parents' information.
"[Advances] have allowed for testing for a specific gene in a greater way than we could a generation ago," says Johns Hopkins University genetics counselor Virginia Corson, citing tests for hemophilia, cystic fibrosis and muscular dystrophy as examples.
Cole and his colleagues created their questionnaire after their discovery of a genetic defect that causes a fatal lung disorder known as surfactant protein-B deficiency. The rare disorder causes severe breathing problems and early death. The only cure is a lung transplant.
"Breathing problems are among the most common problems for infants, and [we can now find out] whether there is an inherited contribution for breathing difficulties," Cole says.
By identifying, through the questionnaire, those fetuses at risk for the disorder, Cole and his colleagues have been able to more quickly diagnose a baby with the condition, and in six cases have performed successful lung transplants.
Cole and his fellow researchers are now working to identify genetic variants of the protein-B deficiency that might be less severe than the one they've found but could still contribute to breathing difficulties in infants.
"Our hypothesis is that there may be more babies whose gene only works 'slightly badly,' " he says.
Cole says genetic mapping isn't the only reason to have a prenatal history.
"For instance, it appears that babies that are born with low-birthweights are at an increased risk of heart attacks," he says.
If there's a family history of low-birthweight babies, he would work with the mother-to-be to increase the baby's weight.
"Reducing the number of low-birthweight babies might have favorable consequences," Cole says.
What to Do: A summary of the types of prenatal testing available for parents can be found at Radio Rounds. The ethical issues surrounding prenatal genetic testing are addressed by the American Academy of Pediatrics.