Genetics
Gene study shows way to help save orangutans
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Orangutans are notoriously slow and gentle, and a study of their DNA shows they have evolved in a similar way, researchers reported on Wednesday.
The findings, published in the journal Nature, could help conservationists do a better job of saving the endangered great apes and might provide insights into human health.
“In terms of evolution, the orangutan genome is quite special among great apes in that it has been extraordinarily stable over the past 15 million years,” Richard Wilson of Washington University in St. Louis, the genomics expert who oversaw the study, said in a statement.
Mount Sinai researchers develop mouse model to help find how a gene mutation leads to autism
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Researchers from Mount Sinai School of Medicine have found that when one copy of the SHANK3 gene in mice is missing, nerve cells do not effectively communicate and do not show cellular properties associated with normal learning. This discovery may explain how mutations affecting SHANK3 may lead to autism spectrum disorders (ASDs). The research is currently published in Molecular Autism.
“We know that SHANK3 mutation plays a central, causative role in some forms of autism spectrum disorders, but wanted to learn more about how it does this,” said Joseph Buxbaum, PhD, Director of the Seaver Autism Center and Professor of Psychiatry, Neuroscience and Genetics and Genomic Sciences at Mount Sinai School of Medicine. “These data provide critical insight into the mechanism behind the development of the cognitive and social changes associated with autism.”
Previous research has shown that gene mutation in SHANK3 is associated with delayed language abilities, learning disability, and ASDs.
Gene therapy prevents memory problems in mice with Alzheimer’s disease
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Scientists at the Gladstone Institute of Neurological Disease (GIND) in San Francisco have discovered a new strategy to prevent memory deficits in a mouse model of Alzheimer’s disease (AD). Humans with AD and mice genetically engineered to simulate the disease have abnormally low levels of an enzyme called EphB2 in memory centers of the brain. Improving EphB2 levels in such mice by gene therapy completely fixed their memory problems. The findings will be published in the November 28 issue of the journal Nature.
In both humans and mice, learning and memory requires effective communication between brain cells called neurons. This communication involves the release of chemicals from neurons that stimulate cell surface receptors on other neurons. This important process, called neurotransmission, is impaired by amyloid proteins, which build up to abnormally high levels in brains of AD patients and are widely thought to cause the disease. But how exactly these poisonous proteins disrupt neurotransmission is unknown.
“EphB2 is a really cool molecule that acts as both a receptor and an enzyme,” said Moustapha Cisse, PhD, lead author of the study. “We thought it might be involved in memory problems of AD because it is a master regulator of neurotransmission and its brain levels are decreased in the disease.”
Study finds gene links to common lymphoma cancer
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Scientists have found three new gene variations linked to the development of Hodgkin lymphoma, one of the most common cancers in young adults, and say the findings should help in the development of better treatments.
Around a quarter to half of all cases of Hodgkin lymphoma, a type of cancer originating from white blood cells called lymphocytes, are thought to be triggered by infection with Epstein-Barr virus (EBV), but the disease can also develop in patients who have never been exposed to the virus.
Scientists had suspected genetic factors might be involved, since having a family history of the disease increases risk, but until now they had not been able to identify any specific genetic risk factors.
Researchers find 95 genes affecting cholesterol
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A scan of the full human DNA sequence has turned up 95 genes that affect blood cholesterol, including a few affected by drugs on the market and others that might be the basis of new drugs, researchers said on Wednesday.
Their findings demonstrate that regulating cholesterol levels is even more complex than many people knew but also point to some short-cuts to prevent heart disease.
The variations they found account for between a quarter and a third of the inherited variation in cholesterol levels and triglycerides, the researchers report in the journal Nature. Diet and exercise can also greatly affect cholesterol levels.
Poor health? Easier for some to blame bad genes than change lifestyle
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Does knowing that genes are partly responsible for your health condition mean you are less likely to be motivated to find out about the benefits of behavioral changes? According to Dr. Suzanne O’Neill from the National Human Genome Research Institute/National Institutes of Health, and her colleagues, people on the whole are still interested in how health habits affect disease risk. However, those with the greatest need to change their behaviors are more likely to favor genetic explanations for their diseases and the more behavioral risk factors they have, the less likely they are to be interested in behavior change information. The study1 is published online in Springer’s journal Annals of Behavioral Medicine.
The completion of the Human Genome Project has led to increased availability of genetic risk information linking gene variants to a number of common health conditions. There is some concern that this genetic risk information might prompt some individuals to give genetic causation undue importance while downplaying the contribution of well-known behavioral and environmental factors, leading to reduced motivation to make behavioral changes. This potential misinterpretation of genetic information may undermine public health efforts to promote the behavioral changes needed to prevent disease.
Researchers find gene linked to birth defects
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An international group of researchers has identified the genetic cause of an inherited condition that causes severe foetal abnormalities.
The work, co-led by geneticists at the University of Leeds, together with colleagues from institutes and universities in Paris, Rome and San Diego, should allow couples at risk of conceiving babies with the profoundly disabling Meckel-Gruber and Joubert syndromes to be identified beforehand through genetic screening.
Their findings, which show how the disease gene stops cells’ finger-like antennae or ‘cilia’ from detecting and relaying information, may ultimately lead to treatments for more common related disorders, such as spina bifida and polycystic kidney disease. The paper is published in Nature Genetics today.
“Personal” study shows gene maps can spot disease
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Two studies published on Wednesday show it is possible to sequence the entire gene maps of families with inherited diseases and pinpoint the offending bit of DNA.
The studies, which would not have been possible a year or two ago, are the first real delivery of the promised transformation of medical science from the Human Genome Project’s mapping of the human genetic code.
One was also made possible by some of the $5 billion that U.S. President Barack Obama directed to the National Institutes of Health in September from the $787 billion economic stimulus package.
Gene doping a risky route to glory for athletes
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Gene therapy offers Olympic athletes a tempting new way to go for the gold, but the technology is far too risky a way to cheat, a top gene therapy expert said on Thursday.
Gene doping - in which DNA is introduced into the body through an inactivated virus or by other means - can alter a person’s genetic make up and improve athletic performance by building muscle and increasing blood flow.
“We know we can introduce genes now to correct disease. It’s not a great leap to say we can also change genes related to normal human performance, like those required for athletic performance,” said Dr. Ted Friedmann, director of the Center for Molecular Genetics at the University of California’s San Diego’s School of Medicine.
Genes in mother, baby raise risk of preterm birth
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Genes in the mother and the fetus play a role in the risk of preterm labor, a leading cause of infant death and disability, U.S. government researchers said on Thursday.
They said gene variants in the mother and fetus can make them susceptible to an inflammatory response to infections inside the uterus, raising the risk that a baby will be born early - before 37 weeks of gestation.
A preterm baby has a 120 times greater risk of death than a baby born full term, and survivors are at risk of breathing difficulties, bleeding into the brain, and having a significant neurologic handicap such as cerebral palsy.
Loss of “Guardian Angel” Gene Prompts Premature Birth
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Mutation of a gene that helps protect the body from genetic instability leads to cellular and molecular changes in the pregnant uterus that trigger premature birth, according to a study appearing online Feb. 1 in the Journal of Clinical Investigation.
The research by scientists in the Division of Reproductive Sciences, part of the Perinatal Institute at Cincinnati Children’s Hospital Medical Center, sheds new light on the still poorly understood genetic and physiological reasons for preterm births. The findings could help lead to the development of new strategies for treating and preventing prematurity, according to Sudhansu K. Dey, Ph.D., director of Reproductive Sciences at Cincinnati Children’s and the study’s senior investigator.
“Preterm birth and prematurity are problems that pose huge long-term social and economic liabilities, and there is an urgent need for research with new approaches to combat this public health concern,” Dr. Dey said.
Genetic Risk Factor Identified for Parkinson’s Disease: Gene Variant Influences Vitamin B6 Met
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Munich, January 11, 2010. An international team of doctors and human geneticists has identified a new genetic risk factor for Parkinson’s disease. The institutions involved in the study were the Institute of Human Genetics of Helmholtz Zentrum München and Technische Universität München, the Neurological Clinic of Ludwig-Maximilians-Universität Munich (LMU) and the Mitochondrial Research Group of Newcastle University, Newcastle upon Tyne, UK.
“Our study reveals the interaction of genetic and environmental factors such as dietary habits in the pathogenesis of Parkinson’s disease,” explained Dr. Matthias Elstner of the Neurological Clinic of LMU and Helmholtz Zentrum München, lead author of the study. In addition, this genome-wide expression and association study confirms that vitamin B6 status and metabolism significantly influence both disease risk and therapy response (Annals of Neurology, January, 2010).
Scientists of the two Munich universities and Helmholtz Zentrum München investigated neurons in the brain to determine which genes modify their activity in Parkinson’s disease. Among other findings, the research group detected increased activity of the pyridoxal kinase gene.
Gene variant protects against Alzheimer’s
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People with a gene linked to long life and good health are also less likely to develop Alzheimer’s disease, U.S. researchers said on Tuesday.
They said people with two copies of a certain version of the cholesteryl ester transfer protein or CETP gene had significantly slower memory declines compared with people who had different versions of the gene.
“We’ve known for a long time that genetic factors matter in Alzheimer’s disease,” said Dr. Richard Lipton of Albert Einstein College of Medicine at Yeshiva University in New York, whose study appears in the Journal of the American Medical Association.
In Early Heart Development, Genes Work in Tandem
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Studying genes that regulate early heart development in animals, scientists have solved a puzzle about one gene’s role, finding that it acts in concert with a related gene. Their finding contributes to understanding how the earliest stages of heart development may go awry, resulting in congenital heart defects in humans.
Peter J. Gruber, M.D., Ph.D., a cardiothoracic surgeon at The Children’s Hospital of Philadelphia, led a study published this week in the Jan. 15 issue of the Journal of Biological Chemistry. Occurring in approximately 1 in 200 children, congenital heart defects represent the most common human birth defect.
“We uncovered a role for the Gata5 gene, a role that has been unappreciated in vertebrate cardiac development,” said Gruber. “Gata5 is a gene that is essential to heart development in other animals, such as frogs and zebrafish, but contrary to expectations, deleting this gene seemed to have no effect on the hearts of mammals. We found, however, that in mice, this gene cooperates closely with other genes to affect heart development. It may work similarly in humans.”
Scientists find new leukemia gene risk factors
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Researchers have found four new genetic variants that increase the risk of contracting one of the major forms of leukemia, confirming that risk factors for the fatal blood cancer can be inherited.
The findings mean scientists now know of 10 genetic variants associated with chronic lymphocytic leukemia (CLL), scientists at Europe’s Institute of Cancer Research who conducted the study said.
The four new genetic factors are all common in European populations and each factor contributes to an increase in the risk of the disease.
