LIU Post Expert: New Test of Fetal Genes Poses Questions, But Holds Promise
Morgan Lyle,Assistant Director of Public Relations
LIU Post, Long Island University
Brookville, N.Y. -- The ability to map the entire genome of a fetus with a simple test of the parents' blood and saliva is a major advance in genetic science, but may also be a source of worry for parents because the implications of the results may not be clear, according to an expert in genetic counseling from Long Island University.
Revealing mutations in the genetic code of a fetus can alert parents to possible problems, said Donna Blumenthal, MS CGC, associate director of the genetic counseling program at LIU Post in Brookville, N.Y. But the test may also reveal mutations whose significance has not yet been determined.
"There is a very significant likelihood of finding unusual variants in the DNA whose significance is completely unknown," Blumenthal said. "Having to deal with the unknown is the dilemma."
The new test, developed by researchers at the University of Washington, was reported this week in the journal Science Translational Medicine. The authors note that while the test is non-invasive, it also requires expensive technology and is likely years away from widespread availability.
While the test may raise more questions than it answers, it can also provide parents with important knowledge of their unborn child's health, with the help of genetic counselors who can provide context, Blumenthal said. While the new test is the first to map a fetus' entire genome, tests already exist that can diagnose conditions like Down syndrome, or identify genes associated with cancer.
"We face similar questions now, in sequencing the BRCA 1 and 2 genes in breast cancer genetic patients," Blumenthal said. "When unknown variants arise in sequencing the BRCA 1 and 2 genes, the genetic counselor collects as much info as possible about that variant, such as how many times has the variant been reported, what was the health status of those patients who have the variant, does the biochemical nature of the variant suggest that it is similar to other deleterious mutations or to benign changes in DNA, and so on.
"More importantly, prior to testing, the genetic counselor informs the patient of the possibility of uncertain results so that the patient can choose to decline testing altogether. Unfortunately, too many patients have testing without counseling and are not given the opportunity to ponder the consequences of testing until it's too late."
The LIU Post Master of Science in genetic testing, launched in 2010, is the only program of its kind on Long Island and one of fewer than 35 in the country. For more information, visit www.liu.edu/post/genetic.
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