Genetics
“Personal” study shows gene maps can spot disease
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
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
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
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
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
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
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
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.
Researchers to Test First Gene Therapy For Alzheimer’s Patients
Mount Sinai School of Medicine is one of 12 sites nationwide participating in the first Phase 2 clinical trial to test gene therapy treatment for Alzheimer’s disease. The study is the first multicenter neurosurgical intervention in Alzheimer’s research in the U.S.
The experimental treatment utilizes a viral-based gene transfer system, CERE-110, that makes Nerve Growth Factor (NGF), a naturally occurring protein that helps maintain nerve cell survival in the brain. CERE-110 has been previously studied in animals, where it reversed brain degeneration in aged monkeys and rats. For this study, CERE-110, will be injected by a neurosurgeon directly into the nucleus basalis of Meynert (NBM) of the brain, an area where neuronal death occurs in Alzheimer’s patients.
In animal studies, NGF has been shown to support the survival and function of the neurons that deteriorate in Alzheimer’s patients.
Iron Overload: Treatment for Common Genetic Disorder
Absorbing and storing too much iron can cause an array of health problems—for starters, joint pain, fatigue, weakness and loss of interest in sex. This condition, called hemochromatosis, is the most common genetic disorder in the United States, most frequently occurring in people of Northern European descent.
The October issue of Mayo Clinic Health Letter provides an overview of hemochromatosis, including its genetic cause, subtle early symptoms, potential health risks and treatment.
When people have hemochromatosis, their bodies absorb and store too much iron from their normal diet. Over decades, the iron levels can build up in various organs, most often the liver and heart. Without treatment, iron levels accumulate to 20 times that of a person without the disorder. The result can be irreversible scarring of the liver (cirrhosis), liver cancer, diabetes, heart failure, heart rhythm problems, arthritis, impotence or darkening of the skin.
New chromosomal abnormality identified in leukemia associated with Down syndrome
Researchers identified a new chromosomal abnormality in acute lymphoblastic leukemia (ALL) that appears to work in concert with another mutation to give rise to cancer. This latest anomaly is particularly common in children with Down syndrome.
The findings have already resulted in new diagnostic tests and potential tools for tracking a patient’s response to treatment. The research, led by scientists from St. Jude Children’s Research Hospital, also highlights a new potential ALL treatment. Clinicians are already planning trials of an experimental medication targeting one of the altered genes.
This study is published in the October 18 online edition of Nature Genetics.
“A substantial proportion of children with ALL lack one of the previously identified, common chromosomal abnormalities. Also, children with Down syndrome have an increased risk of ALL, but the reasons why are unclear,” said Charles Mullighan, M.D., Ph.D., assistant member in the St. Jude Department of Pathology. Mullighan is senior author of the study, which involved scientists from 10 institutions in the U.S. and Italy. “Our results have provided important data regarding the mechanisms contributing to leukemia in these cases,” he said.
Faulty gene may explain sudden deaths in epilepsy
A common gene that can cause abnormal heart rhythms can also trigger epileptic seizures in the brain and may explain the sudden, unexplained deaths that often occur in people with epilepsy, U.S. researchers said on Wednesday.
Testing epileptics for a mutation in this gene could give doctors the information they need to prevent some of these deaths, said Dr. Jeffrey Noebels of Baylor College of Medicine, whose study appears in the journal Science Translational Medicine.
Doctors have long known that patients with a mutation in the gene KvLQT1—which makes structures called ion channels that regulate electrical activity in the heart—have a greater risk of sudden death from abnormal heart rhythms.
Scientists find three new gene links to Alzheimer’s
Scientists have found three new major genetic links to Alzheimer’s, affecting up to 20 percent of people with the brain-wasting disease, and said on Sunday it was the most significant such discovery in 15 years.
Two large studies found that the three new genes join the better-known APOE4 gene as significant risk factors for the most common cause of dementia.
“If we were able to remove the detrimental effects of these genes through treatments, we could reduce the proportion of people developing Alzheimer’s by 20 percent,” Julie Williams, a professor of Neuropsychological Genetics at Britain’s Cardiff University, told a news conference in London.
Diabetes Gene Raises Odds of Lower Birth Weight
Pediatric researchers have found that a gene previously shown to be involved in the development of type 2 diabetes also predisposes children to having a lower birth weight. The finding sheds light on a possible genetic influence on how prenatal events may set the stage for developing diabetes in later childhood or adulthood.
Researchers from The Children’s Hospital of Philadelphia and the University of Pennsylvania School of Medicine published the study July 10 in the online version of the journal Diabetes.
“It’s a bit unusual to find a gene linked to both prenatal events and to a disease that occurs later in life,” said study leader Struan F.A. Grant, Ph.D., a researcher at the Center for Applied Genomics of The Children’s Hospital of Philadelphia. “This gene variant carries a double whammy, in raising the risk of both lower birth weight and the development of type 2 diabetes in later life.”
Common Cold Virus Efficiently Delivers Corrected Gene to Cystic Fibrosis Cells
Scientists have worked for 20 years to perfect gene therapy for the treatment of cystic fibrosis, which causes the body to produce dehydrated, thicker-than-normal mucus that clogs the lungs and leads to life threatening infections.
Now University of North Carolina at Chapel Hill School of Medicine scientists have found what may be the most efficient way to deliver a corrected gene to lung cells collected from cystic fibrosis patients. They also showed that it may take this high level of efficiency for cystic fibrosis (CF) patients to see any benefit from gene therapy.
Using parainfluenza virus, one of the viruses that causes common colds, the UNC scientists found that delivery of a corrected version of the CFTR gene to 25 percent of cells grown in a tissue culture model that resembles the lining of the human airways was sufficient to restore normal function back to the tissue.
