dnawellnessinfo.com

Smokeless tobacco may hurt DNA, enzymes

CHANDIGARH, India, June 18 (UPI) — A researcher in India warns smokeless tobacco use may damage the body’s DNA and key enzymes.

Krishan Khanduja of the Postgraduate Institute of Medical Education and Research in Chandigarh, India, suggests smokeless tobacco not only may damage DNA, but may also affect the normal functioning of a key family of enzymes found in almost every organ.

Khanduja and colleagues found laboratory rats exposed to extracts of smokeless tobacco had altered DNA material in the liver, kidney and lungs — as well as changed function of the CYP-450 family of enzymes. This enzyme group affects many functions including the production of hormones such as estrogen and testosterone, the processing of cholesterol and vitamin D and the breaking down of prescription drugs and possibly toxic substances.

The study, published in Chemical Research in Toxicology, noted use of smokeless products is increasing not only among men but also among children, teenagers and women.

“These products are used around the world but are most common in Northern Africa, Southeast Asia, and the Mediterranean region,” the study authors said in a statement. “Most of the users seem to be unaware of the harmful health effects and, therefore, use smokeless tobacco to ‘treat’ toothaches, headaches, and stomachaches.”

DNAWellnessinfo.com Resource: http://www.upi.com/Health_News/2010/06/18/Smokeless-tobacco-may-hurt-DNA-enzymes/UPI-41481276902848/

DNA handling under the microscope

By ACT court reporter Katherine Pohl

Updated Mon May 31, 2010 8:27am AEST

The use of DNA evidence in criminal court cases is under the spotlight with state and territory attorneys-general backing a review into collecting and testing procedures.

Questions have been raised about contamination and the risks of convicting someone on DNA evidence alone.

“Those two areas are of critical concern, not only to defence lawyers but to prosecutors as well,” New South Wales Deputy Senior Public Defender Andrew Haesler said.

Those issues have been recently examined by the High Court.

Benjamin Forbes was found guilty of sexually assaulting a Canberra teenager in 2005 as she walked home from work.

DNA was the only evidence linking him to the crime scene.

The High Court ruled that it was not a suitable test case on which to base a DNA challenge.

But Mr Haesler predicts it will not be long before such a case comes along.

“Judges and juries have to be very critical when evidence is presented that identifies an offender solely on the basis of DNA,” he said.

Contamination of DNA evidence is also a major issue.

Simon Walsh from the Australian Federal Police admits DNA evidence can be a double-edged sword.

“One of the advantages of the testing progress and technology is that it allows us to test very small amounts of DNA,” he said.

“The corollary of that is that it makes it potentially more susceptible to contamination.”

Contamination issues were at the centre of a case in Victoria earlier this month in which a man was wrongly convicted of rape because of tainted DNA evidence.

The case has prompted all state and territory attorneys-general to back a review of DNA collection and analysis.

ACT Attorney General Simon Corbell says there is a lot to learn from that particular case and he is encouraging prudent collection and testing procedures.

A working group is examining the issues.

DNAWellnessinfo.com Resource: http://www.abc.net.au/news/stories/2010/05/31/2913474.htm

From Californians’ DNA, a Giant Genome Project

ntimes.com
By SABIN RUSSELL
Published: May 28, 2010

Still in fine fettle at the age of 87, Ruth Young, a retired Oakland school nurse, jumped at the chance, she said, to “spit for the cause.”

Mrs. Young is one of more than 130,000 members of Kaiser Permanente in Northern California who have volunteered to have their DNA scanned by robotic, high-speed gene-reading machines as part of the largest human genome study of its kind ever attempted.

The goal of the study they are participating in is to help scientists uncover the genetic roots of chronic disease and, perhaps, to find out why some people live longer than others.

This month, researchers at Kaiser Permanente in Oakland and the University of California, San Francisco began the highly automated, large-scale process of analyzing that DNA, which is being extracted from tens of thousands of saliva samples donated by Kaiser members in Northern California since 2008.

Each sample of ordinary spit is laden with cells containing the volunteer’s entire set of genes, their genomes, which carry in sequences of DNA the coded instructions for building and maintaining life. The hope for this so-called genome-wide association study is that, when the genes of people with diseases like cancer and multiple sclerosis are compared with the genes of those in good health, computer analysis will pinpoint genes responsible for the illnesses.

With a speed that would have seemed preposterous to contemplate a decade ago, the work of collecting, purifying and digitizing billions of discrete bits of chemical information will be finished in less than 18 months, providing a rich resource for scientists to analyze for decades to come.

Winifred K. Rossi, who is managing the project for the National Institute on Aging, said most genome-wide association studies scan between 5,000 and 8,000 participants, although data from multiple, smaller studies can be pooled to form a larger group. What makes the Kaiser study unique is that members of a single, colossal cohort will have their genomes scanned uniformly, then paired with their medical histories. “It is absolutely the largest study of its kind, and it has enormous statistical power.” Ms. Rossi said.

Mrs. Young, a Kaiser member for 63 years, suffers from arthritic knees and Type II diabetes, which took her father’s life at an early age. “I’m conscientious about my diet, but I do love sweets,” she said.

She had originally been one of nearly two million patients asked in 2007 about participating in the Kaiser study. A huge group of volunteers, ranging in age from 18 to 107, filled out questionnaires. Tens of thousands of them, like Mrs. Young, were asked for specimens.

Following instructions found in a kit mailed to her Oakland home, Mrs. Young deposited the requested spit into a special plastic cup. She sealed it with a blue lid fitted with a built-in preservative and sent it back to Kaiser. Along with her saliva, the samples from the other 130,000 people began arriving in Kaiser’s mailbox.

Experiments like this one underscore how quickly gene-scanning technology is moving from the lab to the home. Last week, officials of the University of California, Berkeley, disclosed that 6,000 incoming freshman and transfer students will be asked to swab their cheeks at home for DNA, to participate in a collective lesson in genetics and a preview of the predicted era when medicine will be tailored to each person’s genetic makeup.

Each student who agrees to participate will be able to tap in a security code on a laptop and check whether they carry gene variants that might affect their ability to process lactose, alcohol or folate, a vitamin found in leafy greens. The Kaiser study participants will not have the same option. Their names are scrubbed from their samples, and only researchers — working with codes instead of names — will be able to link the gene scans to medical histories. Their goal is to discern the larger picture, hoping to spot associations between genes and health that would not show up until very large numbers of individuals are compared at once.

Although this vast experiment has been contemplated for years, it was given a boost last year when Kaiser and the university won a $25 million grant from the National Institutes of Health as part of the stimulus package.

However, the study has begun just as some scientists have started to question the value of these experiments, and when private ventures, like 23andMe, are struggling to find a consumer market for gene tests.

David B. Goldstein, a Duke University researcher, said he believed “interesting and valuable information” would come from the Kaiser study, but he questioned whether it was the most efficient way to gather information about the genetic links to disease. “It’s an awfully expensive study,” Dr. Goldstein said in an e-mail message.

He added, “We have literally hundreds of genome-wide association studies for common diseases, and in most cases we are having trouble making much use of them.” While Dr. Goldstein stresses that discoveries are being made using that technique, he believes that a different approach — sequencing the entire genetic code of fewer patients rather than scanning the genome for variations — “is likely to yield more useful returns.”

For Kaiser, the federal grant is just the beginning of a long-term endeavor.

In the coming years, 400,000 more members will be asked to contribute their DNA to the project when they come in for routine blood work. Kaiser is spending $9 million to build a repository for the blood samples.

“It’s an idea whose time has come,” said Dr. Pui-Yan Kwok, an investigator at the Institute for Human Genetics at the University of California, San Francisco, where the genes are being scanned. “The genotyping technology is here, the electronic medical records are here.”

Using high-precision robots to process each sample, the genomes of 2,500 participants are being analyzed each week. The genetic information will be stored in computers for future studies by scientists all over the globe.

At the same time, Elizabeth Blackburn, a Nobel-prize winning biologist at the university, and her lab will be conducting a mass experiment on a separate set of 100,000 samples of DNA from the Kaiser patients. They will be measuring the length of telomeres — wads of DNA at the top and bottom of every chromosome that, like shoelace tips, keep them from unraveling when a cell divides. Telomere length tends to shorten with age, and shorter telomeres tend to be linked with shorter life spans.

“Telomere length is more reflective of things that happen in your life than the genetic hand you are born with,” said Dr. Blackburn.

She said that the Kaiser patients are a valuable resource for science because their detailed medical histories can be matched with the varied measurements of telomere length and matched to the gene scans that will be done for each participant as well. Her targets are the three top diseases that kill the elderly: cancer, cardiovascular disease and diabetes.

At the Kaiser research lab, a production line of robotic equipment has been set up to process the 130,000 cups of saliva that have been mailed by patients and stored, at room temperature, in racks of cardboard “pizza boxes,” 50 cups to a box. Here, the robots draw out a sample of spit, and chemically process it to extract the donor’s DNA.

One set of Mrs. Young’s DNA will be sent to Dr. Blackburn’s lab, where the length of its telomeres will be measured. A second set will arrive at Dr. Kwok’s newly equipped facility, where the genome of each Kaiser participant will be scanned using an array of robots, each costing about a quarter million dollars.

At Dr. Kwok’s ninth-floor lab, three sets of robots prepare the DNA samples shipped from Oakland. The full complement of DNA from each volunteer is washed over a custom-designed silicon chip about this size of small fingernail. Microscopic wells etched into the chip are each engineered to pluck out one of 675,000 possible gene variants.

“Our biggest fear is a power-failure,” said Dr. Kwok. Each array, filled with 96 processed DNA samples, costs $10,000.

DNAWellnessinfo.com Resource: http://www.nytimes.com/2010/05/30/science/30sfgenome.html?pagewanted=1

UPDATE 1-Benefits trump risks of rotavirus vaccine-US panel

By Lisa Richwine

GAITHERSBURG, Md., May 7 (Reuters) – Benefits from rotavirus vaccines made by GlaxoSmithKline Plc (GSK.L) and Merck & Co Inc (MRK.N) outweigh any risk from recently discovered contamination with a pig virus, members of a U.S. advisory panel said on Friday.

Pieces of DNA from porcine circovirus (PCV) have been detected in Glaxo’s Rotarix and Merck’s Rotateq. The U.S. Food and Drug Administration said there was no evidence the virus harms people.

Several members of a Food and Drug Administration advisory panel said the vaccines carried impressive benefits from preventing rotavirus, which can cause fatal diarrhea, and agreed there was no sign so far of illness in people from PCV.
Any risks “are at best theoretical,” said Dr. Melinda Wharton, a panelist and deputy director of the Center for Disease Control and Prevention’s National Center for Immunization and Respiratory Diseases.

“Based on where we are with current knowledge, to me the known benefits clearly outweigh the risks,” she said.

The panel did not take any votes on formal recommendations to the agency.

In March the FDA advised doctors to stop using Rotarix after PCV-1 was found in the vaccine. Merck then tested its vaccine and the FDA announced on Thursday the company found pieces of DNA from PCV-1 and a related virus, PCV-2.

The FDA said it wanted the advisory panel’s input before making new recommendations on either vaccine. The agency will issue its latest advice “in the very near future,” said Karen Midthun, acting head of the FDA unit that reviews vaccines. “We need to consider this very expeditiously,” she told reporters.

Both PCV1 and PCV2 are common in pigs but neither is known to cause illness in humans, the FDA said. PCV2 is believed to cause postweaning multisystemic wasting syndrome in young piglets, marked by diarrhea and an inability to gain weight.

Advisory panel members urged further study to check for any long-term effects from PCV. Some also said parents needed to be told about the PCV finding.
“The fact that it poses no risk in the short term is certainly comforting. I don’t think that necessarily says it’s risk-free in the long term,” said panelist Stephen Hughes, head of the HIV drug resistance program at the National Cancer Institute.

Some panelists said they wanted to know more about PCV2. The committee heard less about that type as Merck’s finding was so recent. The meeting was originally scheduled just to discuss the Glaxo vaccine.

PCV1 apparently has been in Glaxo’s vaccine since it was first developed, the company said. Testing found DNA from the virus in master cells used to make the product.

The material may have come from a pig-derived enzyme called trypsin used early in development, Glaxo officials said.

“All available data support this is a manufacturing quality issue and not a safety issue. PCV1 does not pose a risk for infants vaccinated with Rotarix,” said Dr. Barbara Howe, a Glaxo vice president.

Glaxo said it planned to develop a rotavirus vaccine free from PCV1 but the process would take time.

Merck was not scheduled to speak at the meeting, but the company said on Thursday the levels of DNA from PCV were low in Rotateq and there was no sign it was harmful to people.

Vaccines against rotavirus have a troubled history. Wyeth’s Rotashield was pulled off the market in 1999 after it was linked with a rare but deadly bowel obstruction.

Rotavirus kills more than 500,000 infants each year, mostly in low- and middle-income countries. In the United States, deaths from the virus are rare but it caused more than 50,000 U.S. hospitalizations annually before Merck’s vaccine won FDA approval in 2006.

The World Health Organization and the European Medicines Agency have not recommended any changes in rotavirus vaccine use in Europe or developing countries.

In 2009, sales of Merck’s vaccine totaled $522 million, including $468 million from the United States.

Most of Glaxo’s rotavirus vaccine sales occur outside the United States. Worldwide sales in 2009 were $440 million, including $118 million from the United States. Glaxo’s vaccine won U.S. approval in 2008. (Reporting by Lisa Richwine, editing by Gerald E. McCormick and Carol Bishopric)

DNAWellnessinfo.com Resource: http://www.reuters.com/article/idUSN0712973220100507

Canadian scientists crack hidden DNA code

Last Updated: Wednesday, May 5, 2010 | 1:11 PM ET

Canadian researchers have unraveled a genetic “code within a code” that helps explain how the instructions for building complex organisms, like humans, can be found in a small number of genes.

University of Toronto scientists Brendan Frey and Benjamin Blencowe said they have found a hidden code in DNA that helps explain how a small number of genes can contain instructions for a larger number of proteins and structures.

When researchers fully sequenced the human genome in 2004, they were surprised at how few genes humans actually have.

“Human DNA has 22,000 genes. That might seem like a lot, but not when you consider that a poplar tree has 45,000,” said Frey, in a statement.

Frey said his team, including Blencowe and Yoseph Barash, found a second level of information that the cells of living organisms use to create a larger set of instructions.

“We discovered a hidden code within DNA that living cells use to turn 20,000 genes into hundreds of thousands of genetic messages, by rearranging their parts,” he said.

Barash and Frey, who is also a professor of computer science and engineering, created a computer program that analyzes DNA to find “code words” in the genome.

The code words together are called the “splicing code,” containing the biological information needed to splice together different parts of the genetic code in different orders to generate a greater number of messages.

“For example, three neurexin genes can generate over 3,000 genetic messages that help control the wiring of the brain,” said Frey.

Neurexin is a protein that glues together the connections between nerve cells in the brain.

Frey said their work is the result of a close collaboration between computer scientists and experimental biologists.

“Understanding a complex biological system is like understanding a complex electronic circuit. Our team ‘reverse-engineered’ the splicing code using large-scale experimental data generated by the group,” he said.

The research was the cover story in this week’s issue of the journal Nature.

DNAWellnessinfo.com Resource: http://www.cbc.ca/technology/story/2010/05/05/tech-dna-splicing-code.html#ixzz0n9Wn5yO0

DNA referees

By Amber Dance, Special to the Los Angeles Times

May 3, 2010

Your life story depends upon a combination of the DNA you’re stuck with plus your environment, including all the little choices and events that happen over that lifetime.

But in recent years, researchers have discovered that, while DNA lays out the options, many of those life experiences — the foods you eat, the stresses you endure, the toxins you’re exposed to — physically affect the DNA and tell it more precisely what to do.

The cause: a kind of secondary code carried along with the DNA. Called the “epigenome,” this code is a set of chemical marks, attached to genes, that act like DNA referees. They turn off some genes and let others do their thing. And although the epigenome is pretty stable, it can change — meaning lifestyle choices such as diet and drug use could have lasting effects on how the body works.

“The thing I love about epigenetics is that you have the potential to alter your destiny,” says Randy Jirtle, who studies epigenetics at Duke University Medical Center in Durham, N.C.

Twins provide an example of how environment can affect the actions of our DNA. Identical twins have identical genes, but sometimes one twin has autism or cancer while the other remains healthy. Studies show that as twins age, their epigenomes become less and less alike, probably causing a lot of those differences in fate.

Another provocative study: In 2009, researchers at Duke University Medical Center published a study in the journal BMC Medicine on epigenetics and autism. They found that some children with autism had extra DNA referees turning off a gene needed to respond to oxytocin, a hormone important in social interaction. The study was small, including only 40 children, but it suggests that turning off that one gene could cause the social problems people with autism have.

Many pharmaceutical companies are exploring the potential of epigenome-altering medicines: There are already a few cancer drugs that turn off cancer-promoting genes or turn on cancer-fighting ones. But since altering the epigenome could have far-reaching, unintended consequences, many scientists are wary of drugs targeted at less life-threatening conditions.

In short, the study of epigenetics is “booming,” says Dana Dolinoy, a toxicologist at the University of Michigan School of Public Health in Ann Arbor.

Pick and choose

The regular DNA genome carries the code for every recipe involved in making a human (or antelope, or philodendron or whatever) — it’s like “The Joy of Cooking.” But just as some chefs never crack, say, the veggies chapter, while they dog-ear every page on desserts, different parts of the body pick and choose the genes they need.

The epigenome is part of what tells different cells in the body which DNA recipes to read and which to ignore. The small chemicals that attach to the DNA may cover up or restrict access to genes that aren’t needed and keep others wide open and readable.

Jirtle compares the system to a computer: The DNA is the hardware — set and unchanging — and the epigenome is the software that tells it when, where and how to work.

Epigenetics might be especially important for pregnant women and infants, because much of the epigenetic code is laid down early in development. Dolinoy speculates that the time before puberty might also be important, since the genome and epigenome are gearing up to launch new genetic programs.

The chemicals that make up epigenetic codes ultimately come from diet. Folic acid, for example, is needed to produce epigenetic molecules that turn off many unwanted genes. Broccoli and garlic are good sources of other types of chemical tags that are part of the epigenome.

In a classic experiment published in 2003 in the journal Molecular and Cellular Biology, Jirtle showed how diet can affect these DNA referees. He studied certain mice that can have either brown or yellow pups. He showed that when pregnant mice eat lots of folic acid and other vitamins, they have mostly lean, brown pups. If those mothers instead eat a diet without the epigenome-enhancing supplements, they have more fat, yellow pups, which are prone to diabetes.

The DNA of the pups is the same — but mom’s diet determined how they used those genes.

Dolinoy used the same types of mice to examine how bisphenol A, a toxin common in hard plastics, affects the epigenome of unborn mice. In a 2007 paper in the Proceedings of the National Academy of Sciences, she reported that mice whose diet included bisphenol A produced more fat, yellow pups. But eating folic acid counteracted those negative effects.

Human mothers, not just rodent ones, affect their children’s epigenomes. In a study published last year in the American Journal of Respiratory and Critical Care Medicine, scientists at USC’s Keck School of Medicine found that if the mother smoked during pregnancy, there were long-lasting changes in her children’s epigenomes. The authors speculated that these changes could affect how the body turns on genes for cancer and development.

Dolinoy, who is expecting her second child in May, cautions that women concerned about epigenome changes in their kids should not base health decisions on this still-immature science. For example, she advises not to overdo it with prenatal supplements. While some folic acid is certainly good — it prevents birth defects — too much might alter the epigenome in unknown, undesirable ways.

“My philosophy is, everything in moderation,” she says.

The epigenome can also be altered after a person is born. For example, researchers from McGill University and the Douglas Mental Health University Institute in Montreal found that child abuse can affect DNA referees. In a 2009 paper in the journal Nature Neuroscience, the authors report that 12 people who were abused as children, and later committed suicide, had different DNA referees on a gene needed to cope with stress, compared with 24 people who were not abused. The research implies, although in no way proves, that diminished ability to cope with stress might have been a factor in the suicides.

Adult epigenomes are still somewhat malleable, but they are stable compared with those of developing fetuses and infants. So there’s no need to worry that every little action will alter it.

But there are also short-term referees that jump on or off the DNA at a moment’s notice. Many scientists consider these refs to be outside the classical definition of “epigenetics,” but those chemical changes do affect genes in similar ways. They may change in response to what you had for breakfast today, or the stress you feel after a tough day.

Genes are not just “on” or “off.” They can be on just a little bit, on a lot and everything in between. So referees, both the short-term and long-term types, tune genes up or down, rather like the dimmer switch for a lamp.

And many genes can be turned up or down by changes in behavior and environment. For example, researchers at the Preventive Medicine Research Institute in Sausalito, Calif., studied 30 men with prostate cancer. These men declined traditional medical treatment and instead underwent a three-month program that included a healthy diet, moderate exercise and daily stress management.

When the researchers examined gene activity in the men’s prostate biopsy samples, they found that 48 genes were turned up and 453 were turned down, compared with gene activity at the beginning of the study. The authors noted that the study, published in the Proceedings of the National Academy of Sciences in 2008, was small and needs to be repeated to be sure of the effects. They also suggested that similar changes might happen in healthy people too, when they alter their behavior.

Though the science of epigenetics is young, scientists think there’s good reason to think about how lifestyle choices may affect the epigenome.

It’s known already that some referees can be inherited from human parent to child. Praeder-Willi syndrome, for example, is caused when some of Dad’s DNA referees or genes are missing. Among other symptoms, people with the syndrome have an overactive appetite that can easily lead to obesity.

And though it hasn’t been proved, some scientists suspect that DNA referees laid down generations ago — in your grandparents, for example — are still active in your body today. That is, the epigenome may “remember” the environment Grandpa grew up in and set your genes to match it, even if you have different foods and activities than he did.

Such control over one’s DNA is a double-edged sword, Jirtle says. Healthy choices, such as eating right, could lead to helpful referees, but unhealthy activities, such as smoking, could have a negative effect on you — and your descendants.

“You now have a major responsibility … to optimize your epigenome,” he says.

health@latimes.com

DNAWellnessinfo.com Resource: http://www.latimes.com/news/health/la-he-epigenetics-20100503,0,5900529.story?page=1&utm_medium=twitter&utm_source=twitterfeed

DNA Swap Between Eggs May Curb Inherited Disorders, Study Finds

April 14, 2010, 4:59 PM EDT  BusinessWeek

By Kristen Hallam

April 14 (Bloomberg) — Scientists discovered a way to transfer DNA from one fertilized human egg to another in a pioneering effort to avert the spread of a host of genetic disorders such as learning disabilities and diabetes.

The researchers at Newcastle University in northern England extracted the genetic material contributed by the egg and sperm and implanted it into a donor egg, according to the study published today by the journal Nature. It’s the first time DNA has been transferred between two fertilized human eggs.

The approach discards almost all the defective DNA inherited from the mother that disrupts the tiny energy generators inside cells, and may prevent related disorders such as blindness and liver failure, the researchers said. They are planning further experiments to see whether the technique could help people who carry mutated genes to have healthy babies — an end result that may still be a decade away.

“We have no way of curing these diseases at the moment, but this technique could allow us to prevent the diseases occurring in the first place,” said Doug Turnbull, the lead researcher and a professor at the university’s medical school, in a statement. “It is important that we do all we can to help these families and give them the chance to have healthy children, something most of us take for granted.”

Parents contribute a total of 23,000 genes to a child. In a fertilized egg, this genetic material is housed in two pronuclei, one from the egg and one from the sperm. The egg also contains mitochondria, tiny structures found in every cell that produce the chemical fuel needed for life. Mutations in the mitochondrial DNA, which are passed on from the mother, can disrupt the functioning of these energy generators.

‘Changing the Batteries’

The Newcastle scientists were able to extract both pronuclei and implant the material that makes each child unique into a donor egg with healthy mitochondria. They created 80 fertilized eggs using the technique and grew them in a laboratory for six to eight days. That showed for the first time that eggs produced in this way could reach the stage at which they each had divided into about 100 cells.

“It’s like changing the batteries,” Turnbull said today at a news conference in London. “These are diseases where there is battery failure. Because mitochondria are everywhere, these diseases can affect all parts of the body. None of my patients is exactly the same.”

About 1 out of every 200 children is born each year with mutations in mitochondrial DNA that cause no symptoms or only mild conditions. One in every 6,500 children is born with a more serious mitochondrial disease, ranging from muscular weakness to fatal heart failure. Some disorders lead to death in early infancy.

The research was funded by the Muscular Dystrophy Campaign, the U.K. Medical Research Council and the London-based Wellcome Trust, the world’s second-biggest medical research charity.

–Editors: Phil Serafino, Angela Cullen

To contact the reporter on this story: Kristen Hallam in London at khallam@bloomberg.net

To contact the editor responsible for this story: Phil Serafino at pserafino@bloomberg.net

DNAWellnessinfo.com Resource:  http://www.businessweek.com/news/2010-04-14/dna-swap-between-eggs-may-curb-inherited-disorders-study-finds.html

DNA Test Misses Virus That Causes Hearing Loss

April 13, 2010, 16:00 EST

DNAWellnessinfo.com Resource:  http://www.businessweek.com/lifestyle/content/healthday/637947.html

Additional genes associated with age-related macular degeneration identified

April 12, 2010

A large genetic study of age-related macular degeneration (AMD) has identified three new genes associated with this blinding eye disease—two involved in the cholesterol pathway. Results of this large-scale collaborative study, supported by the National Eye Institute (NEI), part of the National Institutes of Health, were published online April 12 in the Proceedings of the National Academy of Sciences.

“Genome-wide association studies require large numbers of patients to discover significant genetic associations. The success of this effort was made possible by a community-wide scientific collaboration of sharing DNA samples and analyzing the genomes of more than 18,000 people,” said Paul A. Sieving, M.D., Ph.D., NEI director. “This study increases our understanding of DNA variations that predict individual risks of AMD and provides clues for developing effective therapies.”

AMD is a leading cause of visual impairment and blindness in older Americans. Researchers have previously discovered genes that account for a significant portion of AMD risk through genome-wide association studies (GWAS), which scan the entire DNA of individuals to uncover genetic variations related to certain diseases.

The recent large GWAS was led by Anand Swaroop, Ph.D., currently chief of the NEI Neurobiology-Neurodegeneration and Repair Laboratory, and Goncalo Abecasis, D.Phil., professor of biostatistics at the University of Michigan, Ann Arbor.

The strongest AMD genetic association found in the study was in a region on chromosome 22, near a gene called metalloproteinase inhibitor 3 (TIMP3). Mutations in the TIMP3 gene were previously found to cause Sorsby’s fundus dystrophy, a rare inherited early-onset form of macular degeneration. Although further research is needed, it is likely that the genetic region pinpointed influences the expression of TIMP3.

Provided by National Institutes of Health

DNAWellnessinfo.com Resource:  http://www.physorg.com/news190294287.html

Key protein aids in DNA repair

April 11, 2010- physorg.com

Scientists have shown in multiple contexts that DNA damage over our lifetimes is a key mechanism behind the development of cancer and other age-related diseases. Not everyone gets these diseases, because the body has multiple mechanisms for repairing the damage caused to DNA by aging, the environment and other human behaviors – but the mechanisms behind certain kinds of DNA repair have not been well-understood.

In a paper published today in the journal Nature, researchers at the University of North Carolina at Chapel Hill’s Lineberger Comprehensive Cancer Center have shown that a particular protein – called Ku – is particularly adept at healing damaged strands of DNA.

According to Dale Ramsden, PhD, associate professor in the department of biochemistry and biophysics and a member of the curriculum in genetics and molecular biology, Ku is a very exciting protein because it employs a unique mechanism to repair a particularly drastic form of DNA damage.

“Damage to DNA in the form of a broken chromosome, or double strand break, can be very difficult to repair – it is not a clean break and areas along the strand may be damaged at the level of the fundamental building blocks of DNA – called nucleotides,” he notes.

Broken chromosomes can be compared to a break in a strand of yarn made up of several different threads or plies. Unless scissors are used to cut the yarn, the strand frays and may break or be damaged at several different places up and down the length of the yarn. These rough ends get “dirty” – making them harder to repair.

Provided by University of North Carolina

DNAWellnessinfo.com Resource:  http://www.physorg.com/news190207556.html