Written by smh.com Friday, 14 January 2011 14:07
A new genetic test could soon allow couples to screen themselves for hundreds of recessive diseases to prevent them passing them on to their offspring.
American researchers reported the new test was capable of detecting 448 inherited conditions such as cystic fibrosis, fragile X syndrome and sickle-cell anemia.
The researchers, from the Drexel University College of Medicine in Philadelphia, said couples could be screened before conceiving so they could make informed reproductive choices thereafter.
For example, if a couple was told it had a 25 percent chance of having a baby with cystic fibrosis, they could opt to use sperm donation or in vitro fertilization to select unaffected embryos for implantation.
They could also have further screening during pregnancy at about 12 weeks with a view to abort an affected fetus. While such tests could significantly reduce the incidence of such diseases in the community, critics say they create unnecessary alarm about rare diseases and could lead to more abortions.
In a report on the finding in Science Translational Medicine, the researchers said their test would also be suitable to screen infants for treatable or preventable diseases where early diagnosis is beneficial.
The director of the Victorian Clinical Genetics Services, David Amor, said that although a similar genetic test to screen people for about 100 diseases became available on the Internet last year, this test represented a new and more powerful tool for accurately testing individuals for a very large number of recessive genes.