New Prenatal Genetic Test Developed

Posted on Dec 10, 2010 by Sergio Ulloa (G+)

Researchers at the Chinese University of Hong Kong announced on Wednesday the discovery of a new form of non-invasive genetic screening for unborn children. This test, which builds on previous research, differs from currently available prenatal screening technologies in that it does not require amniotic fluid samples. Traditional methods of prenatal genetic screening, known as Amniocentesis, have required the womb of the mother to be pierced in order to retrieve genetic samples, which carried a risk to the child. The new screening method, announced on Wednesday November 9 2010, only requires a blood sample from the mother. This major breakthrough is based on the discovery that foetal genes comprise approximately 10 percent of a mother's blood plasma, meaning that there is now no need to risk the health of the baby, or induce stress on the mother, by directly piercing the womb. Once a blood sample has been obtained the researchers use a super computer to analyze the genetic sequence of the child in order to determine if there is any risk of a hereditary disease or congenital birth defect. In a field trial, researchers from the university took a sample from a pregnant woman at the Sha Tin Prince of Wales Hospital and found the results to be exactly the same as if they had sampled the amniotic fluid in the mother's womb - the child was a thalassemia carrier, but did not suffer from the condition. Researchers were quick to point out that the test was, for the most part, undeveloped; commercial applications of the screening may be some time away. Due to the nature of the study, and that fact the test was developed for research purposes, the new method of screening currently costs US$ 200,000 per sample. However, according to the lead researcher, Professor Lo Yuk-Ming, the likelihood of a decrease in cost was high; in his view the blood screening method of prenatal genetic testing could cost approximately US$ 2,000 in as little as 5 years time. Professor Lo Yuk-Ming stated that the drop in cost would be attributable to smarter sampling methods. Currently the researchers test the entire genome of the child which contributes to the high price tag, but by focusing on the genetic predispositions of the population in question the test could be made to focus on a few specific genes where the probability of a genetic risk is high. While the new test can screen for all genetic conditions only 5 to 10 defects would be looked at in the future. For the Hong Kong population the professor cited concerns such as degenerative muscle disease, thalassemia, and Pompe disease as some of the primary concerns to be looked at in future trials. However, even with the lowered price tag of US$ 2,000 in the future, the new test will still be three times as expensive as the current Amniocentesis method, which currently costs US$ 512 per sample in Hong Kong hospitals. Professor Lo stated that the costs associated with the test, even at their lowered level, would be out of reach for most Public Hospital users in Hong Kong, and that it would take around a decade for the new test to replace current genetic screening methods. In the view of global medical inflation it is likely that the costs associated with prenatal genetic testing will remain high, but it remains to be seen whether international insurance providers will cover this type of proactive screening as a maternity insurance policy standard. Currently, only a limited number of insurance providers will cover Amniocentesis under their plans, for the most part this coverage is limited to women over 35 where the screening is deemed to be medically necessary (i.e. there is a heightened risk of genetic defects for the child) - this coverage is by no means universal within the industry. The development of a safer, non invasive, prenatal genetic screening test is only the latest in a number of developments within the field of medical technology. With the news that a daily dose of aspirin can prevent cancer, and the development of a new drug to combat HIV/Aids, medical researchers continue to extend their fight against illness in the 21^st century.