Tag Archives: Gene
THURSDAY March 14, 2013 — In a very early sign of medical progress on the osteoarthritis front, scientists report they’ve used injections of modified genes to reduce the risk that mice will develop the painful, debilitating condition.
There’s no way to know if the gene therapy treatment will help humans, and scientists are far from understanding the treatment’s side effects and potential cost. But the findings are more than just good news for mice with creaky joints.
“This work identifies an approach that can make a difference,” explained study co-author Dr. Brendan Lee, director of the Rolanette and Berdon Lawrence Bone Disease Program of Texas. “There’s a great need for treating and preventing osteoarthritis.”
The disease, the most common form of arthritis, appears as your joints deteriorate with aging. It often strikes the hands, knees, neck and hips, causing pain, stiffness and difficulty moving.
Seventy percent of Americans aged 55 to 70 struggle with osteoarthritis, for which there is no cure. Doctors try to treat the pain and improve the ability of patients to move, Lee said, and may turn to joint replacement surgeries in advanced cases.
In the new study, researchers examined a protein that diminishes in people with a rare joint disorder. The protein appears to be crucial to the lubrication of joints.
Researchers injected a gene related to the protein into mice and found that the rodent bodies began producing it. The mice appeared to be resistant — but not immune — to damage to the cartilage of joints from injury and aging, Lee said.
There are plenty of caveats.
The research is in mice, not humans; the next step is to test the approach in horses, whose joints are similar to those of people. And the gene therapy doesn’t seem to do anything for damage that’s already occurred.
“This kind of therapy would probably not be very useful in patients who have advanced disease,” Lee said, adding that the treatment would likely have to be used with other strategies.
Dr. Joanne Jordan, director of the Thurston Arthritis Research Center at the University of North Carolina at Chapel Hill, said the findings “would be really very exciting if this translates up into humans.” The study, she said, appears to be reasonable and especially strong because it looks at osteoarthritis in the mice from different angles.
Currently, Jordan said, treatments for osteoarthritis, such as painkillers, come with potentially severe side effects. And in many cases, she added, the damage is done by the time people notice there’s a problem.
The study is published in the March 13 issue of Science Translational Medicine.
For more about osteoarthritis, visit the U.S. National Library of Medicine.
Posted: March 2013
TUESDAY Nov. 13, 2012 — Researchers have identified a genetic variant that seems to put men who are heavy drinkers at high risk of developing chronic pancreatitis.
The genetic variant on the X chromosome near the claudin-2 gene was discovered during a 10-year study that included more than 2,000 people. The variant was found on the X chromosome in 26 percent of men without pancreatitis and in nearly 50 percent of men with alcoholic pancreatitis.
Women have two X chromosomes and it appears that most of those with this high-risk variant on one X chromosome are protected from alcoholic pancreatitis if their other X chromosome is normal.
Men, however, have an X chromosome and a Y chromosome, so they have no protection if their X chromosome has the high-risk variant.
The variant on the X chromosome does not appear to cause pancreatitis, but increases the risk of chronic pancreatitis if a person suffers a pancreatic injury, especially if they drink alcohol, explained the University of Pittsburgh School of Medicine researchers.
The study was published online Nov. 12 in the journal Nature Genetics.
Chronic pancreatitis is a progressive inflammatory disease that causes permanent damage to the pancreas. The condition affects more than 100,000 people in the United States. Alcohol is considered a major risk factor for adult-onset chronic pancreatitis, but only about 3 percent of alcoholics develop the disorder, which suggests that there is a factor specific to the pancreas.
“The discovery that chronic pancreatitis has a genetic basis solves a major mystery about why some people develop chronic pancreatitis and others do not,” study lead author Dr. David Whitcomb, professor of medicine, cell biology and physiology, and human genetics, said in a university news release.
“We also knew there was an unexpected higher risk of men developing pancreatitis with alcohol consumption, but until now we weren’t sure why,” he said. “Our discovery of this new genetic variant on chromosome X helps explain this mystery as well.”
The study findings may enable doctors to identify people with early signs of pancreatitis or an attack of acute pancreatitis who are at very high risk for progressing to chronic pancreatitis. These patients can then receive treatment to slow the development of the disease and allow the pancreas a chance to heal.
The U.S. National Institute of Diabetes and Digestive and Kidney Diseases has more about pancreatitis.
Posted: November 2012
WEDNESDAY Nov. 7, 2012 — Scientists have discovered a new gene, known as Atpif1, that enables the body to make hemoglobin — the protein in red blood cells that is responsible for transporting oxygen in the blood.
In their study, researchers from Brigham and Women’s Hospital in Boston revealed that loss of this critical blood cell gene seems to result in severe anemia or a lower than normal number of red blood cells or levels of hemoglobin. They said that the findings provide new insight into anemia and could lead to the development of improved treatments for the condition.
Using zebrafish, the researchers cloned the Atpif1 gene, which regulates the production of hemoglobin during the formation of red blood cells. They found the loss of this gene results in severe anemia.
After examining data on the human form of Atpif1, first study author Dhvanit Shah, of the hospital’s division of hematology, and colleagues said the gene is essential for normal red blood cell differentiation. Any deficiency in this gene, they added, might play a role in certain human diseases.
Older people and women of childbearing age are at greater risk for anemia. Babies and children also are at risk for the condition due to iron deficiency from their diet or lead poisoning, the researchers said.
The study was published in the Nov. 7 online edition of the journal Nature.
The U.S. National Library of Medicine has more about anemia.
Posted: November 2012
MONDAY Oct. 8, 2012 — Dozens of newly discovered genetic mutations that play a significant role in the development of schizophrenia add to the list of genetic variants linked to the disease, new research suggests.
Schizophrenia typically appears in people during their teens or early adulthood, but many of these newly identified mutations are most active during fetal development, according to researchers from Columbia University Medical Center in New York City.
They said their findings show that both the function of the mutated gene and the timing of when the gene is expressed seems to have a major effect on the risk of developing schizophrenia.
The genetic errors pinpointed in this study are spontaneous, or “de novo” mutations, which means they are present in patients but not in their parents. This supports studies showing that environmental factors, such as malnutrition or infections during pregnancy, can contribute to the development of schizophrenia, the researchers said.
“Our findings provide a mechanism that could explain how prenatal environmental insults during the first and second trimester of pregnancy increase one’s risk for schizophrenia,” study leader Dr. Maria Karayiorgou, professor of psychiatry and acting chief of psychiatric and medical genetics at the New York State Psychiatric Institute, said in a Columbia news release.
“Patients with these mutations were much more likely to have had behavioral abnormalities, such as phobias and anxiety in childhood, as well as worse disease outcome,” she noted.
For the study, the researchers conducted genetic analyses of 231 patient trios from the United States and South Africa. Each trio consisted of a schizophrenia patient and both of his or her parents, who did not have the illness.
The study was published online Oct. 3 in the journal Nature Genetics.
The U.S. National Institute of Mental Health has more about schizophrenia.
Posted: October 2012