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Genetic Test of pregnant women to screen for down syndrome
A safer method to diagnose Down syndrome and other genetic disorders may one day become available using a genetic test performed on blood taken from pregnant women, researchers said.
Scientists from Stanford University and the Howard Hughes Medical Institute used a gene-sequencing method that amplified fragments of DNA found in the mother's blood, including a tiny proportion that comes from the fetus. The novel approach allowed them to detect excess genetic material from a specific chromosome, indicating a problem.
Such a blood test could be easier and less risky than other prenatal tests doctors now use to look for Down syndrome and other chromosomal disorders. The other tests include amniocentesis, which uses amniotic fluid extracted from the uterus and can cause complications including infection and miscarriage.
``We look for chromosomes that are overrepresented,'' said Stephen Quake, professor of bioengineering and applied physics at Stanford and the Howard Hughes Medical Institute. ``The breakthrough is we're able to measure very slight differences very accurately.''
Using the blood test, researchers accurately diagnosed nine cases of Down syndrome, two cases of another genetic disorder, trisomy 18, and one case of trisomy 13, all among 18 pregnant women. Trisomy means there are three copies of a chromosome in each body cell instead of the usual two. The results appeared yesterday in the online edition of the Proceedings of the National Academy of Sciences.
Women Tested
The study included blood drawn from 18 women at the Prenatal Diagnostic Center at Lucile Packard Children's Hospital and one man for comparison. The blood was taken when the women were 10 to 35 weeks pregnant and after a standard test such as amniocentesis was performed. More research is needed to confirm the findings and test the method's accuracy and reliability.
Down syndrome is the most common type of genetic birth disorder, affecting one of every 733 babies born in the U.S., according to the National Down Syndrome Society. It results when a person has three copies of the 21st chromosome and may cause low muscle tone, small stature, an upward slant to the eyes and developmental delays. Edward syndrome, or trisomy 18, and Patau syndrome, or trisomy 13, are less common, involve many complications and are often fatal. A safer method to diagnose Down syndrome and other genetic disorders may one day become available using a genetic test performed on bl... more -
Scientific Progress or Has Big Brother Gone too far?
Should parents be required to have their babies undergo genetic testing?
The governor of Pennsylvania just signed a new law mandating newborn screening for six genetic and metabolic conditions. "Pennsylvania now joins many other states that screen for at least 29 conditions at birth."
Is this a sign of progress, or has government stepped too far? Should parents be required to have their babies undergo genetic testing? ... more -
DNA Testing Company Stops Direct-to-Consumer Sales in California
A genetic testing company has stopped direct-to-consumer sales in California as a result of receiving a cease-and-desist letter from the state's health department.
HairDX, which offers a genetic test that claims to predict clients' risk of hair loss, has decided, on advice of legal counsel, to require California (and New York) residents to order their tests through a doctor.
Other companies targeted by California continue to sell their services in the state, but HairDX's CEO, Andy Gores, said closing down their Internet orders in the market was an easy decision.
"It's not our mainstay business," Gores said. "We are focused mainly on [selling through] doctors."
Still, the company's decision to stop offering its genetic test to California residents is a sign that the Public Health Department's cease-and-desist letters are already having an impact on the nascent genetic testing industry.
On June 9th, the Laboratory Field Services division sent the letters to thirteen genetic testing companies. So far, in addition to HairDX, only Navigenics, 23andMe and DNATraits have confirmed they received a letter.
The Health Department requested responses to the letters by today, June 23, containing plans for coming into compliance with the department's interpretation of California state clinical laboratory testing laws.
Gores, like representatives from other genetic testing companies Wired.com has spoken with, voiced frustration with the health department's one-letter-fits-all regulatory action.
"I think their letter is a shotgun approach," he said. "The 23andMes of the world are more in the entertainment realm... We're on the opposite end of the spectrum."
The company's attorney, Elliott J. Stein, said he was preparing a response for the state, but was unsure of exactly what type of compliance plan the state desired.
"I don't know how all of this is supposed to play out," he said, but was confident that his client's business would ultimately prove acceptable to the health department.
In the meantime, Laboratory Field Services' chief Karen Nickel's declaration that California is "no longer tolerating direct to consumer genetic testing," has already succeeded in pushing one company out of the state. A genetic testing company has stopped direct-to-consumer sales in California as a result of receiving a cease-and-desist letter from t... more -
Big Brother opens door for GINA genetic testing bill
Genetic Information Nondiscrimination Act (GINA) of 2008 is expected to be signed into law by President Bush soon.
GINA will amend laws to prohibit a group health plan from adjusting premium or contribution amounts for a group on the basis of genetic information.
Reluctance to get genetic tests range from being fired, priced out of health insurance or dropped from coverage altogether.
Having been used to diagnose fetal problems for inherited diseases, the scope of testing has expanded in the last decade.
There are now about 1,500 genetic tests.
Washington’s Public Citizen group stated that some people have been misled by inaccurate results, and industry oversight is scant and superficial. As the new law takes effect, testing of the genetic tests also needs to be a priority.
My question: How will Big Brother safeguard the DNA tests? Genetic Information Nondiscrimination Act (GINA) of 2008 is expected to be signed into law by President Bush soon. ... more
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