Category Archives: Genetic Medicine

MENLO PARK, Calif., May 22, 2012 /PRNewswire/ -- In a step toward understanding possible genetic differences in smoking behaviors, a team of researchers co-led by SRI International has identified a genetic marker associated with smoking quantity in people of African ancestry. The study's findings may help guide future public health decisions related to smoking, because the more people smoke, the higher their risk of lung cancer.

The genetic variant, called rs2036527, appears to function as a marker of smoking quantity in African Americans, predicting the number of cigarettes smoked per day. It is on the same nicotine receptor gene, located on Chromosome 15, as another marker previously identified in people of European descent. Earlier studies have also shown that this gene plays a role in limiting nicotine intake by affecting how pleasurable nicotine is, which in turn affects how much nicotine is consumed.

Findings from the Study of Tobacco Use in Minority Populations (STOMP) Genetics Consortium study are published in the May 22, 2012 issue of Translational Psychiatry (part of Nature Publishing Group).

To find the genetic variants for smoking behavior, researchers combined 13 genome-wide association studies. The result included data for genetics and smoking behavior for more than 32,000 African Americans.

Although African Americans are less likely to smoke than European Americans, if they do start smoking, they tend to start smoking later in life, are less likely to quit smoking, and die more often from smoking-related lung cancer. Smoking is the leading cause of premature death among African Americans. STOMP investigators did not assess lung cancer risk, but other researchers have found that the genetic marker (rs2036527) is associated with risk of lung cancer in African Americans.

"This study may have implications for personalized medicine and the need to identify targets for drug discovery," said Sean P. David, M.D., D.Phil., research physician and director of the Translational Medicine program in the Center for Health Sciences in SRI's Policy Division and also a family medicine physician and Clinical Associate Professor of Medicine at Stanford University School of Medicine. "However, we need to be careful not to draw conclusions about the degree to which a genetic variant associated with smoking quantity affects smoker's ability to quit. Future studies of smoking behavior, including smoking cessation clinical trials, should be performed in non-European ancestry groups, so that other informative biomarkers aren't missed."

The STOMP study, done in collaboration with 78 researchers from dozens of academic institutions and the National Institutes of Health, is the first meta-analysis of genome-wide association studies of smoking behaviors among African Americans. Meta-analysis is a powerful technique that combines a number of similar research questions and studies. Using statistical techniques, researchers were able to find genetic linkages to smoking behaviors too subtle to see in small studies.

SRI research was funded 100% by the Department of Health & Human Services (HHS) Grant No. 5-U01-DA-020830-07. The total dollar amount of the grant is $158,221, of which a nominal amount went to support the research described above. SRI received no other source of funding for this work.

About SRI InternationalSilicon Valley-based SRI International, a nonprofit research and development organization, performs sponsored R&D for governments, businesses, and foundations. SRI brings its innovations to the marketplace through technology licensing, new products, and spin-off ventures. SRI is known for world-changing innovations in computing, health and pharmaceuticals, chemistry and materials, sensing, energy, education, national defense, and more.

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Researchers Find Genetic Marker that May Predict Smoking Quantity in African Americans

By Richard Hartley-parkinson

PUBLISHED: 12:11 EST, 16 May 2012 | UPDATED: 06:42 EST, 17 May 2012

A genetic 'map' that could help give more accurate diagnoses of breast cancer has been drawn up, showing the varied landscape of the disease in more detail than ever before.

Researchers at the Wellcome Trust Sanger Institute in Hinxton, Cambridgeshire, say the development will lead to more effective treatments.

They found that rather than being a single disease, breast cancer is a diverse range of cancer species.

Scientists described nine new genes that drive the development of breast cancer, bringing the known total to 40.

The Wellcome Trust Sanger Institute has drawn up a genetic 'map' of breast cancer showing the landscape of the disease in more detail than ever before

The research, conducted by a large international team of British-led experts, involved analysing DNA from 100 tumour samples.

Scientists scoured more than 21,000 genes for cancer-causing 'driver' mutations that can turn an ordinary cell into one that multiplies uncontrollably.

They also identified nine genes previously not known to be linked to the disease.

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New genetic 'map' drawn up that will give better diagnosis for breast cancer patients and more effective treatment

Public release date: 17-May-2012 [ | E-mail | Share ]

Contact: Jane E. Rubinstein jrubinstein@rubenstein.com 212-843-8287 IntegraGen

Toronto, CANADA (May 17, 2012) By focusing on the identification of common genetic variants, researchers have identified 57 single nucleotide polymorphisms (SNPs) that predictwith a high degree of certainty--the risk that siblings of children with Autism Spectrum Disorder (ASD) will also develop the condition. The findings were presented at the International Meeting for Autism Research.

ASD is among the most common form of severe developmental disability with prevalence rates up to 1 in 88 children. Boys are greater than four times more likely to be diagnosed with ASD, while recurrence risks for the sibling of a child with ASD are estimated at 18.7%. Since multiple studies have shown that early assessment and intervention offer significantly improved long-term outcomes, early identification of children at risk of ASD has become a key goal.

Though many recent studies demonstrate that autism has a genetic basis, the inheritance pattern of ASD in most families is highly complex. While genetic testing for autism has been limited to the identification of copy number variants (CNVs), autism-associated CNVs are found only in approximately 10% of children with ASD.

Researchers seeking an alternative approach to identify biomarkers for autism have focused on a number of common genetic variants--or SNPs --that have been shown to be related to the risk of ASD. While individual SNPs do not cause ASD, recent studies have shown that the presence of a combination of autism-associated SNPs can predict with a high degree of certainty whether a child will develop ASD.

"By looking at a combination of gender-specific, risk-associated, genetic common variants, we were able to identify siblings of children with ASD who have a significantly increased risk of developing autism," says lead author Francois Liebaert, MD, Vice President of Research and Development for IntegraGen, SA, Evry, France, "Earlier identification of siblings of children with autism at increased risk may lead to faster referrals, earlier diagnosis, earlier intervention and better prognosis. We also hope to replicate these findings in families that do not have a child with autism."

These findings build upon earlier identification of eight autism-related SNPs that occur in males and females (Autism risk assessment in siblings of affected children using sex-specific genetic scores) published the February 17, 2011 edition of Molecular Autism.

To determine which SNPs were associated with autism, researchers applied techniques that have been used to analyze other complex diseases. By combining statistical results from genome wide association studies (GWAS) with biological information from multiple sources including databases and scientific literature, the researchers were able to identify and prioritize the SNPs, and develop gender-specific genetic scores to predict the risk of autism.

The study comprised greater than 1,100 families which have more than one child diagnosed with ASD, referred to as multiplex families, including nearly 2,000 affected and 600 unaffected siblings. The male to female ratio for affected children was close to 4.2:1. The discovery cohort included 545 families from the Autism Speaks Autism Genetic Resource Exchange Repository (AGRE). The findings were then replicated in a population comprising 627 families including 339 families from a separate AGRE collection and DNA samples from 288 independent families collected at the University of Washington, Seattle and currently maintained at the University of Pennsylvania.

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Common genetic variants identify autism risk in high risk siblings of children with ASD

A new study of the protein-coding genes in 100 breast cancer tumors revealed vast differences among the cancers and highlights how complicated the disease really is, researchers said Wednesday.

A sobering perspective on the complexity and diversity of the disease is emerging, they wrote in the online edition of the journal Nature (subscription required), which is publishing a series of studies of the genetic changes in breast cancer.

The scientists, led by Michael Stratton at the Wellcome Trust Sanger Institute in Hinxton, England, found 73 different combinations of disease-causing mutations in the tumors, each involving up to six different genes from a set of 40 driver genes.

Seven of the 40 individual driver genes were mutated in more than 10% of cases, but 33 others that were less common also contributed to the development of the cancers, the team reported. In 28 cases, a single mutation was enough to cause disease.

The researchers identified nine new genes that caused the cancers, and also found mutations in genes that were already known to cause breast and other cancers.

Discovering that a single disease breast cancer can appear in so many different guises means that developing targeted therapies tailored to a patients tumor type will remain a tall order in the near future.

The situation is more complex than anyone would like to see, said Christina Curtis, an assistant professor of preventive medicine at the Keck School of Medicine at USC and first author of another paper in Nature, released in April, that detailed several new breast cancer subcategories.

But it seems were getting closer, Curtis added. With each study were getting a new vantage point.

Curtis said that finding new driver genes and new combinations of driver genes could still eventually pave the way to new treatment options, once researchers dig further and figure out exactly how the different combinations of mutations change cellular function, causing cancer.

Her team at USC is working on techniques to examine mutations in single cells, which will let scientists study genetic variation within tumors as well as between then.

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Breast cancer study reveals 'substantial genetic diversity'

Public release date: 17-May-2012 [ | E-mail | Share ]

Contact: Raymond MacDougall macdougallr@mail.nih.gov 301-402-0911 NIH/National Human Genome Research Institute

People have increasing opportunities to participate in genetic testing that can indicate their range of risk for developing a disease. Receiving these results does not appreciably drive up or diminish test recipients' demand for potentially costly follow-up health services, according to a study performed by researchers at the National Institutes of Health and colleagues at other institutions.

The study in the May 17, 2012 early online issue of Genetics in Medicine was done by investigators with the Multiplex Initiative, a multi-center collaborative initiative involving investigators from the National Institutes of Health's Intramural Research Program, Group Health Cooperative in Seattle, and the Henry Ford Health System in Detroit.

The tests are available from a growing number of commercial producers, and health care providers have been uncertain whether people who received information only about risk would follow up by demanding diagnostic testing to monitor for predicted illnesses.

The study is the first to use electronic health records -- rather than self-reported behavior -- to measure the impact of genetic testing on the subsequent consumption of health services by commercially insured, healthy adults. Self reports, which can be affected by memory lapses and other problems, tend to be less accurate.

"We need to understand the impact of genomic discoveries on the health care system if these powerful technologies are going to improve human health," said Dan Kastner, M.D., Ph.D., scientific director and head of the National Human Genome Research Institute's (NHGRI) Division of Intramural Research. "We are still learning how to integrate new genomic discoveries into clinical care effectively and efficiently."

"There are a lot of unanswered questions about how genetic test results can be used to guide people towards making positive lifestyle and health behavior changes," said Colleen McBride, Ph.D., chief of NHGRI's Social and Behavioral Research Branch. "This study goes a long way towards bringing data to these debates and shows that people are not likely to make inappropriate demands of health delivery systems if they are properly informed about the limitations of genetic tests."

Genetic tests, such as those used in this study, can detect common variants of genes associated with modest alterations in the chances of developing particular diseases. The term multiplex refers to simultaneously performing multiple genetic tests on a single blood sample.

The study included 217 healthy people between the ages of 25 and 40 who elected to participate in genetic susceptibility testing offered by their health plan. The researchers analyzed health care usage by the participants in the 12 months before genetic testing and the 12 months following the testing. They also compared the test group's behavior with a group of about 400 similar plan members who declined the testing offer.

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NIH-led study finds genetic test results do not trigger increased use of health services

Public release date: 17-May-2012 [ | E-mail | Share ]

Contact: Rebecca Hughes hughes.r@ghc.org 206-287-2055 Group Health Research Institute

SEATTLEPeople have more and more chances to participate in genetic testing that can indicate their range of risk for developing a disease. Receiving these results does not appreciably drive up or diminishtest recipients' demand for potentially costly follow-up health services, according to a new study in the May 17, 2012 early online issue of Genetics in Medicine.

The study was done by researchers with the Multiplex Initiative, a multi-center collaborative initiative involving investigators from the National Institutes of Health's Intramural Research Program, Group Health Cooperative in Seattle, and the Henry Ford Health System in Detroit.

The tests are available from a growing number of commercial producers, and health care providers have been uncertain whether people who received information only about risk would follow up by demanding diagnostic testing to check for predicted illnesses.

The study is the first to use electronic health recordsrather than self-reported behaviorto measure the impact of genetic testing on the subsequent use of health services by commercially insured, healthy adults. Self-reports, which can be affected by memory lapses and other problems, tend to be less accurate.

"Our study was a best-case scenario, because we chose 15 genes reliably associated with relatively small risks for eight common diseases that health behaviors can affect," said the study's first author Robert J. Reid, MD, PhD. Dr. Reid is Group Health's associate medical director of research translation and an associate investigator at Group Health Research Institute. Those diseases were type 2 diabetes, coronary heart disease, high blood cholesterol, hypertension, osteoporosis, lung cancer, colorectal cancer, and melanoma. "We hope that testing positive activates patients to make behavior changes that could lower their risk, such as quitting smoking," he added, "without causing them to make many extra visits to their doctors."

"Understanding personalized genetic information is important because it is becoming more readily available and we need to figure out how to integrate it effectively and efficiently into the clinical care we provide," said coauthor Eric B. Larson, MD, MPH, Group Health Cooperative's vice president for research and Group Health Research Institute's executive director.

"There are a lot of unanswered questions about how genetic test results can be used to guide people toward making positive lifestyle and health behavior changes," said Colleen McBride, PhD, chief of the Social and Behavioral Research Branch at the National Human Genome Research Institute (NHGRI). "This study goes a long way toward bringing data to these debates and shows that people are not likely to make inappropriate demands of health delivery systems if they are properly informed about the limitations of genetic tests."

Genetic tests, such as those used in this study, can detect common variants of genes associated with modest changes in the chances of developing particular diseases. "Multiplex" means simultaneously performing many genetic tests on one blood sample.

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Genetic testing may not trigger more use of health services