Genetics
Experts identify gene variants linked to lung cancer
|
|
Researchers in China and the United States have identified mutations of two genes which appear to make ethnic Chinese more susceptible to lung cancer, they wrote in the journal Cancer.
Their finding involves two genes, ABCB1 and ABCC1, which were previously thought to be linked to eliminating carcinogens from the lungs and protecting them against inhaled toxins.
In their study, the researchers analyzed the genes of 500 patients with lung cancer and 517 cancer-free participants in southeastern China.
Newly identified gene powerful predictor of colon cancer metastasis
|
|
Cancer Researchers at the Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch and the Charité – Universitäts Medizin Berlin (Germany) have identified a gene which enables them to predict for the first time with high probability if colon cancer is going to metastasize. Assistant Professor Dr. Ulrike Stein, Professor Peter M. Schlag, and Professor Walter Birchmeier were able to demonstrate that the gene MACC1 (Metastasis-Associated in Colon Cancer 1) not only promotes tumor growth but also the development of metastasis.When MACC1 gene activity is low, the life expectancy of patients with colon cancer is longer in comparison to patients with high MACC1 levels. (Nature Medicine, doi: 10.1038/nm.1889)*.
According to the National Institutes of Health in Bethesda, Maryland, USA, more than 108,000 people developed colon cancer in the US in 2008. Despite surgery, chemo- and radiotherapy, only 50 percent of patients can be cured because 20 percent of the patients have already developed metastasis by the time their colon cancer is diagnosed. In addition, one-third of patients whose treatment of the original colon cancer was successful will, nevertheless, go on to develop metastasis.
The MDC and Charité researchers are convinced that the identification of the MACC1 gene will aid medical doctors in identifying those patients as early as possible who are at high risk of developing life-threatening metastasis in the liver and the lungs. As a result, more intensive treatment and follow-up care could be offered to high risk patients.
Obesity gene linked with calorie consumption
|
|
The gene mutation associated with obesity—the FTO gene—does not appear to regulate how calories are burned calories, but may influence the amount and choice of food consumed, according to a UK report published in The New England Journal of Medicine.
FTO gene mutations have shown the strongest association with obesity to date, Dr. Colin N. A. Palmer at the University of Dundee, Scotland, and colleagues point out. Yet, the mechanisms by which FTO mutations promote obesity have been unclear.
In 2,726 Scottish children between 4 and 10 years of age, the researchers tested for the FTO mutation rs9939609. All of the children underwent height and weight measurements. In 97 subjects, the link between the FTO mutation and amount of body fat, calories burned and food consumed was explored.
Blood tests may show inherited diseases in fetuses
|
|
Doctors may soon be able to diagnose inherited diseases such as cystic fibrosis, thalassemia and sickle cell anemia in fetuses by simply testing a blood sample taken from the mother.
Until now, prenatal diagnoses of such disorders have been possible only through invasive procedures like amniocentesis, which carry a risk of fetal miscarriage.
Amniocentesis is the extraction of a small amount of fluid from the sac surrounding a developing fetus.
International Team Finds Gene Associated with Epilepsy
|
|
A University of Iowa-led international research team has found a new gene associated with the brain disorder epilepsy. While the PRICKLE1 gene mutation was specific to a rare form of epilepsy, the study results could help lead to new ideas for overall epilepsy treatment.
The findings, which involved nearly two dozen institutions from six different countries, appear in the Nov. 7 issue of the American Journal of Human Genetics.
In epilepsy, nerve cells in the brain signal abnormally and cause repeated seizures that can include strange sensations, severe muscle spasms and loss of consciousness. The seizures may not have lasting effects but can affect activities, such as limiting a person’s ability to drive. Most seizures do not cause brain damage but some types of epilepsy lead to physical disabilities and cognitive problems. Medications can control symptoms, but there is no cure.
Genetics of aging and cancer resistance
|
|
In the November 15th issue of G&D, Dr. Kenneth Dorshkind and colleagues at the David Geffen School of Medicine (UCLA) have identified two genes – p16(Ink4a) and Arf – that sensitize lymphoid progenitor cells to the effects of aging, and confer resistance to leukemogenesis.
Hematopoiesis (the development of blood cells) entails two main pathways: myelopoiesis (the formation of the red and white myeloid cells) and lymphopoiesis (the formation of B- and T-cells). While myelopoiesis remains constant throughout life, lymphopoiesis declines with age.
Dr. Dorshkind and colleagues demonstrated that older B lymphoid progenitor cells preferentially express p16(Ink4a) and Arf, which regulate cell cycle progression to effectively mediate senescence and tumor suppression in these aged cells. In contrast, myeloid progenitor cells consistently expressed much lower levels of these proteins.
Gene Expression May Influence Lack of Response to RA Treatment
|
|
Genes might explain why some patients with rheumatoid arthritis respond better to anti-TNF therapy than others, according to research presented this week at the American College of Rheumatology Annual Scientific Meeting in San Francisco, Calif.
Rheumatoid arthritis is a chronic disease that causes pain, stiffness, swelling, and limitation in the motion and function of multiple joints. Though joints are the principal body parts affected by RA, inflammation can develop in other organs as well. An estimated 1.3 million Americans have RA, and the disease typically affects women twice as often as men.
Drugs known as tumor necrosis factor, or TNF, inhibitors are often prescribed to individuals with rheumatoid arthritis. They work by targeting and blocking the inflammation, and can help reduce pain, morning stiffness, tender and swollen joints, limit damage to the joints and improve function.
Genes affect weight loss drug effectiveness
|
|
A study conducted by researchers at Mayo Clinic shows that obese patients with specific genetic makeup had enhanced response to the weight loss drug sibutramine, while others who lack these genetic factors lost little or no weight.
The findings are published in the October issue of Gastroenterology (http://www.gastrojournal.org).
In this randomized, double-blind, placebo-controlled study, Mayo researchers measured the impact of two different dosage levels of sibutramine (10 or 15 mg daily) combined with behavioral therapy for 12 weeks in 181 overweight or obese participants. Participants received structured behavioral therapy for weight management at four, eight and 12 weeks.
The first autism disease genes
|
|
The autistic disorder was first described, more than sixty years ago, by Dr. Leo Kanner of the Johns Hopkins Hospital (USA), who created the new label ´early infantile autism´. At the same time an Austrian scientist, Dr. Hans Asperger, described a milder form of the disorder that became known as Asperger Syndrome, characterised by higher cognitive abilities and more normal language function. Today, both disorders are classified in the continuum of ´Pervasive Developmental Disorders´ (PDD), more often referred to as Autism Spectrum Disorders (ASD).
The prevalence of (classic) autism in the general population is about 15-20 in 10.000, while all Autism Spectrum Disorders (ASD) affect about 60 in 10.000 children. Males are affected four times more often than females. In approximately 10% of cases, autism is associated with a recognized cause, such as Fragile X Syndrome, Tuberous Sclerosis or diverse chromosomal abnormalities (mean observed rates between 5-10%), but in a vast majority of cases, no known causes are associated with autism.
Gene variant common in Africa increase HIV risk
|
|
A gene variant that emerged thousands of years ago to protect Africans from malaria may raise their vulnerability to HIV infection but help them live longer once infected, researchers said on Wednesday.
The findings could help explain why AIDS has hit Africa harder than all other parts of the world.
People with the version of the gene have a 40 percent higher risk of becoming infected with the human immunodeficiency virus, or HIV, researchers in the United States and Britain wrote in the journal Cell Host & Microbe.
Known Genetic Risk for Alzheimer’s in Whites Also Places Blacks at Risk
|
|
A commonly recognized gene that places one at risk for Alzheimer’s disease does not discriminate between blacks and whites, according to new research led by Florida State University.
FSU Psychology Professor Natalie Sachs-Ericsson and graduate student Kathryn Sawyer have found that the gene APOE epsilon 4 allele is a risk factor for African-Americans as well as whites. Until now, it has been a mainstream belief that the gene is only a risk factor for whites.
“The results of our study have clear implications for research and treatment of Alzheimer’s disease,” Sachs-Ericsson said. “The APOE test might be used as one tool in identifying people who are at risk for Alzheimer’s. We now know that African- Americans and Caucasians alike need to be considered for such risk assessments.”
First gene therapy for heart failure offered at NewYork-Presbyterian/Columbia
|
|
Could injecting a gene into a patient with severe heart failure reverse their disabling and life-threatening condition? Physician-scientists are setting out to answer that question in a first-ever clinical trial of gene therapy to treat severe heart failure.
NewYork-Presbyterian Hospital/Columbia University Medical Center is the only center in the New York City area where the therapy is currently available.
Patients enrolled in the multicenter CUPID trial (Calcium Up-Regulation by Percutaneous Administration of Gene Therapy in Cardiac Disease) will undergo a minimally invasive cardiac catheterization procedure that will introduce a specially engineered gene that stimulates production of an enzyme necessary for the heart to pump more efficiently.
Genetic cause for type of childhood epilepsy identified
|
|
Scientists have identified the mutated gene responsible for development of a type of epilepsy called childhood absence epilepsy, or CAE.
The condition is associated with frequent “absent” seizures where the patient’s consciousness is impaired leaving the child staring blankly ahead not aware or responsive for up to 10 seconds at a time. An inherited disorder, CAE accounts for 10 to 12 percent of epilepsy in children under age 16. CAE often disappears in adulthood.
The scientists studied the DNA of 48 patients with CAE and discovered that 4 patients had a genetic mutation occurring in the GABA receptor, which binds to a neurotransmitter of the brain called GABA that inhibits the excitation of nerve cells. When this regulation is lost or reduced, seizures develop.
Genetic links to impaired social behavior in autism
|
|
Individuals with autism spectrum disorders (ASD) show profound deficits in social interactions and communications, and display repetitive behaviors and abnormal responses to sensory experiences. One aspect of an autistic child’s impaired social abilities is their lack of affiliative behaviors, i.e., behaviors such as touching and hugging that strengthen social bonds. On May 15th, Biological Psychiatry is publishing an article that reports new findings on genetic bases of these behaviors.
In this study, Yale University researchers recruited, genotyped, and clinically assessed a large sample of autistic children and their families. They specifically examined the genetic variants in six genes known to be involved in maternal and affiliative behaviors. Dr. Elena Grigorenko, the senior author, discusses their study, “Animal studies have taught us that genetic factors can play a crucial role in the development of close affiliative ties. With the help of Yale’s Autism Center of Excellence, led by Drs. Ami Klin and Fred Volkmar, and many families of individuals with ASD, we have registered a possible association between some of the genes identified in animal studies as controlling affiliative behaviors in ASD.” The strongest statistical findings of the study implicate the prolactin gene, the prolactin receptor gene, and the oxytocin receptor gene in these affiliative behavior deficits.
Human ageing gene found in flies
|
|
Scientists funded by the Biotechnology and Biological Sciences Research Council (BBSRC) have found a fast and effective way to investigate important aspects of human ageing. Working at the University of Oxford and The Open University, Dr Lynne Cox and Dr Robert Saunders have discovered a gene in fruit flies that means flies can now be used to study the effects ageing has on DNA. In new work published today in the journal Aging Cell, the researchers demonstrate the value of this model in helping us to understand the ageing process. This exciting study demonstrates that fruit flies can be used to study critical aspects of human ageing at cellular, genetic and biochemical levels.
Dr Lynne Cox from the University of Oxford said: “We study a premature human ageing disease called Werner syndrome to help us understand normal ageing. The key to this disease is that changes in a single gene (called WRN) mean that patients age very quickly. Scientists have made great progress in working out what this gene does in the test tube, but until now we haven’t been able to investigate the gene to look at its effect on development and the whole body. By working on this gene in fruit flies, we can model human ageing in a powerful experimental system.”
