Posts Tagged ‘dna testing’
Blood Test Can Tell Fetus’s Sex at Just 7 Weeks
The test analyzes fetal DNA found in a mother’s blood, according to a report in the New York Times. If a Y chromosome is present, the mother is having a boy; if it’s not, it probably means the fetus is female (but could also mean that blood sample doesn’t contain fetal DNA). Researchers examined 57 studies of fetal DNA tests, spanning some 6,500 pregnancies. The results were published in the Journal of the American Medical Association.
This could be good news for parents whose offspring are at risk of rare gender-related genetic disorders, like in boys or in girls. Knowing fetal sex early on would help parents determine whether they need to undergo costly genetic testing. But it also raises questions about selective abortions of undesired genders. The tests are not sold in China or India, where female fetuses are . And at least one company that sells the tests in this country makes parents sign a waiver saying they are not using it for that purpose.
The tests have been available in the US for some time, but their reliability has been contested, sometimes in court. In one particularly sensational example, a pregnant mother was told she was having a boy, but an ultrasound later revealed she was carrying a girl. When she complained, the company told her they were certain “genetically you are having a male,” she told the Times — on the outside, it may look like a girl, but “we’re giving you the results on the inside.”
Given these uncertainties, doctors don’t prescribe the tests, but that could change now that they’ve been proven effective if used properly, the Times says.
The FDA does not regulate them, because they’re not used for a medical purpose, at least not officially. But the agency is studying the kits, the Times says.
In the meantime, the tests’ effectiveness means curious parents who don’t want to be surprised can start painting the nursery really, really early.
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US Government Archived Bin Laden’s Sister’s Brain For DNA Comparison
It’s predictable that the U.S. government, not leaving anything to chance, used DNA to identify Osama Bin Laden’s body. What is more than a little creepy, is that they matched his DNA to that of his sister, who died several years ago of brain cancer, and whose brain the FBI has kept in its hall of brains since then.
The FBI had immediately subpoenaed her body upon her death, in the hopes that it could be used for this exact purpose. They preserved her brain as well as blood and tissue samples to create a DNA profile. This profile, among other things like facial recognition, was used to confirm that the man shot in the raid on the compound in Pakistan, was in fact Bin Laden. The DNA test was conducted in Afghanistan, after which Bin Laden was buried at sea.
New DNA Analysis Reveals Suspects’ Natural Hair Color
Apparently these guys are unfamiliar with hair dye.
Still, the study is an improvement over current hair color-determination tests — previously, only red hair, which is rare, could be determined from DNA. Researchers at Erasmus MC in the Netherlands used DNA and hair color information from hundreds of Europeans, and studied genes known to influence hair color. Ultimately, they identified 13 DNA markers on 11 genes that can serve as hair color predictors.
They could determine whether someone had red or black hair with 90 percent accuracy, and brown or blond hair with 80 percent accuracy. The method can even differentiate between similar colors, like between red and strawberry blond.
The same team has also studied eye color prediction using DNA, and in November, Erasmus MC researchers published a study detailing how to on the basis of DNA material. Certain immune-related DNA molecules inside blood cells decrease with age, according to the researchers. All these biomarker tests can yield a wealth of information from tiny traces left at a crime scene or a disaster, said researcher Ate Kloosterman of the Department of Human Biological Traces at the Netherlands Forensic Institute.
“This new development results in an important expansion of the future DNA toolkit used by forensic investigators to track down unknown offenders,” he said.
Just as long as they don’t dye their hair.
National Forensic Canine DNA Database To Help Combat Dogfighting
“We can tie blood spatter on pit walls and clothing, or blood trails found outside of the pit, to a specific dog and tell his story for him,” says Beth Wictum, director of the forensics unit of the Veterinary Genetics Laboratory in at the University of California-Davis veterinary school, in a press release. “We become the voice for those victims.”
The Canine Combined DNA Index System, or Canine CODIS, includes more DNA markers than are normally tested, allowing for better comparisons. That provides more power when calculating match probability, which is then used in criminal proceedings. The database will be maintained at UC-Davis, and law enforcement agencies will be able to pay a fee to have dog DNA analyzed and matched.
Blood collected from dog fighting sites will also be checked against the database to identify the animals, UC Davis says.
The canine CODIS is similar to the human one, which law enforcement officials use to match suspects to DNA profiles found at crime scenes.
The American Society for the Prevention of Cruelty to Animals, the Humane Society of Missouri and the Louisiana SPCA established the database using DNA from dogs seized in investigations, along with unidentified samples collected at dog-fighting venues.
It includes DNA from dogs seized in a near St. Louis last year, the largest in the country. More than 400 dogs were seized after an 18-month investigation and more than two dozen people in Missouri and Illinois were arrested.
Condo Board May Screen Resident Dogs’ DNA to ID Wayward Poo
Someone has not been doing his or her civic, um, duty and picking up Fido's waste, leaving messes all over the ritzy condo grounds, according to the Baltimore Sun.
Members of the condo board want to find out who's responsible, so they're turning to the same technology used to connect suspects to crime scenes and to prove paternity.
Under the proposal, every dog who lives at the condo and all visiting dogs would get a cheek swab so their DNA could be tested. Condo residents who own dogs would have to fork over $50 to cover the costs of sending poo samples to a lab. If wayward doggie doo matches a specific dog, the culprit's owner would face a $500 fine.
The point is to encourage residents to pick up after their pets, says Steve Frans, the board member who came up with the idea, according to the Sun.
"Some people think it's funny. But you know, this seems to be a reasonable, objective way to say, 'This is your poop, you're responsible,'" he said.
The Sun notes that some condo residents have been "muttering a lot about Big Brother and draconian measures."