Biopeer

Scientists discover link between genes and Restless Leg Syndrome

Scientists at Emory University in Atlanta, USA, and deCODE Genetics in Reykjavik, Iceland, have discovered genes that are linked to Restless Leg Syndrome (RLS). "We now have concrete evidence that RLS is an authentic disorder with recognizable features and underlying biological basis," said David Rye, professor of neurology at Emory University School of Medicine. The researchers examined 300,000 bits of DNA to find the difference between people with and without RLS. The team discovered a link between a common variant of the gene, BTBD9 and RLS, and periodic limb movements in sleep. “This is the most definitive link between genetics and RLS that has been reported to date," said Dr. Rye. "We have known for quite some time that the majority of RLS patients have a close family member with the disorder, and now we have found a gene which is clearly linked to RLS."

A study published in the July 18 issue of the New England Journal of Medicine found a gene variant that can double the risk of developing the degenerative eye disease AMD, or age-related macular degeneration. The scientists based their findings on studies of patients with AMD, who were compared with 701 unaffected people. The study found that a variant in the complement C3 gene influenced the risk of developing AMD. The findings would provide better understanding of blindness in older people and lead to potential treatment and possibly prevention.

Researchers at the University of Leicester and the University of Leeds, in collaboration with researchers at the Universities of Lubeck and Regensburg, have found six new genetic variants that increase the likelihood of developing coronary artery disease. The scientists analyzed 2,000 people with coronary artery disease and 3,000 healthy controls. “We can now examine the whole genome quickly to produce great results - something that couldn’t have been done at all a few years ago,” said Jeremy Pearson, associate medical director of the British Heart Foundation.

Powered by Qumana

Gene mutation discovery may lead to therapy for dementia

Scientists at the Regional Neurogenetic Centre in Lamezia Terme, Italy, have identified a new gene mutation linked to frontotemporal dementia. The researchers identified a new mutation in the gene progranulin among an extended family in Italy. Researchers conducted DNA tests on 70 family members, 13 of whom had the disease. The new gene mutation showed up in nine family members already affected by the disease, and 10 others who are currently too young to have the symptoms of the disease. "Another intriguing aspect in this Italian family is the variable age at onset, which ranged from 35 to 87 years in the family members who inherited the same mutation," said Ekaterina Rogaeva, from the Center for Research in Neurogenerative Diseases at the University of Toronto. "Our future research will try to identify the modifying factors responsible for the severity of the disorder." Amalia Bruni, from the Regional Neurogenetic Centre, believes that the findings of this study may help scientists better understand the disease and develop potential therapies.

Researchers at Johns Hopkins University found new evidence that many of the genetic bits and pieces that drive evolutionary changes do not confer any advantages or disadvantages to humans or other animals. The study demonstrated that one of the major architectural markers of the human genome, DNA repeat elements that make up over 40% of our genome, rose to prominence without offering any benefits to the organism. By comparing the sequences of human numts with those in different animals, the study has uncovered a possible reason why these potentially damaging, but mostly neutral, bits of DNA accumulate over time. "When new species emerge, their numbers and therefore their genetic differences are very small," said Nicholas Katsanis, associate professor at the Hopkins Institute of Genetic Medicine. "This creates a genetic bottleneck during which any changes in the genome will either get eliminated quickly or spread to the whole population quickly."

Powered by Qumana

Gene detection to prevent chronic diseases

A study published in the Journal of the American Medical Association by Ophthalmic, Epidemiology and Genetics Service Tufts-New England Medical Center, claims that two genetic variants, CFH Y402H and LOC387715 A69S, can determine age-related macular degeneration (AMD) in older people, to necessitate prevention of the same. Six years of genotypic analysis involving 1,500 adults aged 55 to 80 with the earlier intermediate signs of macular degeneration, confirmed the link of the genes with the progression of AMD, later found in 281 individuals. However, refined studies are required for worst cases of AMD developing in the absence of both the genotypes.

Findings published in the Proceedings of the National Academy of Sciences USA, by Gabriel Corfas, a professor of neurology at Harvard Medical School’s Children’s Hospital Boston, has reported the effect of the gene erbB4 on schizophrenia. Study involved blocking the erbB4 receptor of mice, in oligodendrocytes, resulting in abnormal development of 40% more oligodendrocytes. Contrary to expected inference of successive branching in the oligodendrocytes, the altered mice developed fewer splitting points and branches, resulting in a thinner myelin coating over neurons. The study of altered erbB4 might facilitate the early detection of remyelination and control the white matter disorder in an early phase.

The scientific journal of the American Academy of Neurology reports about the involvement of chromosome 3 and chromosome 18 in causing febrile seizures. The study used genetic linkage to examine four generations of a French family, detecting chromosome 3 in 13 childhood febrile seizures, later modified by chromosome 18 to develop epilepsy in adulthood. The detection of these genes in childhood can prove to be efficient in preventing the occurrence of epilepsy or brain disorder in adulthood.

Powered by Qumana

Study reveals impact of chemotherapy

Through a breakthrough research study, American scientists have been able to pinpoint the genes affecting the impact of chemotherapy on cancer cells. They used a technique to screen the human genes and found 87 genes that determined the reaction of cancer cells to particular chemotherapy drugs. They then deactivated a few of the 87 genes inside isolated lung cancer cells. These cells had a 10,000 times higher sensitivity towards the drug paclitaxel. This signifies that the dosage of these drugs can be reduced without reducing their effectiveness. However further studies need to be conducted to test the findings on living animals.

Another study, conducted at Yale University, found no link between gene mutations and heart disease. The researchers analyzed the genetic profiles of 1,500 subjects in order to study 85 genes that had been associated, through earlier tests, with heart trouble. About half the subjects suffered from heart disease. However, the researchers found only one gene mutation that had even the slightest connection to heart problems. Therefore, they could not provide proof for the earlier association. This discovery plays a significant role in proving the authenticity of genetic tests, which are becoming increasingly popular.

Meanwhile, British researchers have found that the FTO gene is partially responsible for weight gain. They tested the blood samples of 38,000 people, who were mostly Caucasians. They realized that those carrying one copy of the gene mutation had a 30 percent higher chance of obesity, while those who had two copies had a nearly 70 percent higher risk. About one in six cases carried two copies of the gene variation, who on an average weigh 7 pounds more than others. This study has explored how biology plays a role in excessive weight gain and obesity.

Powered by Qumana

Genetic studies give hope to cancer research

In a surprising discovery, scientists from across the globe have found several new gene mutations causing cancer. More than 60 scientists, after conducting an extensive survey, studied over 500 genes, 200 cancers and over 250 million letters of the DNA code, as part of the Cancer Genome Project. They discovered 120 genes that were earlier not known to cause the growth of cancer cells. The researchers studied kinase genes and pinpointed two kinds of gene mutations, driver and passenger, that lead to cancer. Since it is difficult to identify driver genes, these have been overlooked several times. A better understanding of gene mutations will help in the development of better cancer therapies.

Another study at St. Jude Children’s Research Hospital revealed new mutations leading to pediatric acute lymphoblastic leukemia (ALL). The scientists utilized microarrays to study over 350,000 markers known as single nucleotide polymorphisms and examined samples of the cancer from 242 children suffering from ALL. They found a high rate of mutations of genes that operate as master regulators of normal B-cell development and differentiation. The findings indicate the feasibility to identify easily the genetic lesions, which are the main cause of ALL. Further knowledge of the leukemic cells will help in the development of improved methods of treatment.

Meanwhile, a team of researchers from the Dana-Farber Cancer Institute, Boston discovered that a known anticancer gene also stimulates skin tanning. The scientists exposed mice to UV rays and found that those without the p53 gene did not tan at all. Apart from encouraging the skin to tan and protecting it from the harmful UV rays, the p53 gene also boosts the release of beta-endorphin, making tanning addictive. Scientists are now working to develop a new lotion that will stimulate p53 without causing any UV damage.

Powered by Qumana

Genetic research unearths vital links

American Researchers from the Ohio State University Medical Center have developed a gene therapy for preventing amputation in limb ischemia. Amputation is undertaken due to poor blood circulation. In Phase I clinical trial, the researchers tested the safety of treating the limbs with study drug, Ad2/HIF-1a/VP16. This drug is a modified form of the hypoxia-inducible factor-1 alpha (HIF-1a) gene, the gene that stimulates the growth of blood vessels, normalize oxygen levels and thus help the tissue to survive. In the trial, the therapy completely eliminated pain in around 50 per cent of the patients while it healed ulcers in more than 25 per cent of the patients. Phase II clinical trials are currently underway.

Meanwhile, researchers from the Washington University School of Medicine, US, have compiled evidence that links gene CHRM2 to intelligence quotient (IQ). The psychiatrists found that this gene stimulates certain signaling pathways that influence performance IQ. Also, certain changes in the gene correspond to the differences found in visual-motor coordination and other such skills. However, the researchers stress that this gene does not decided whether an individual will be a genius or not.

In another study, researchers from the Yale School of Medicine are on the brink of linking a cancer gene LRP6 to heart and bone disease. While studying 58 members of the same family, they saw that those with mutations in the LRP6 gene also suffered from high levels of LDL cholesterol, blood pressure and triglycerides. They also noticed that a significant number of members had osteoporosis. The researchers believe that their findings are a first step in finding a genetic connection between deteriorating bones and heart disease.

Powered by Qumana

Gene studies bring new hope

Diabetes research got a boost when an international research team pinpointed four points on the human gene map that are linked to type 2 diabetes. Researchers from the Imperial College London, UK, McGill University, Canada and the Pasteur Institute of France, among other institutions, together examined 392,935 single nucleotide polymorphisms (SNPs) belonging to participants with and without type 2 diabetes. After extensive comparisons, the researchers narrowed down the points or loci to four. The loci were those concerned with insulin regulation, including a mutation of zinc transporter SLC30A8. The scientists are hopeful that these findings will help them find a way to confirm a person’s predisposition to diabetes and thereby prevent its occurrence by suggesting dietary and other lifestyle changes.

Meanwhile, researchers from the Breast Cancer Association Consortium have confirmed that the gene CASP8 reduces the risk of breast cancer. After examining SNPs from nine genes, they concluded that a variation in the CASP8 gene reduced the risk for women carrying it by 10 per cent. On the other hand, a variation in the TGF-beta1 gene raised the risk of developing the disease by 7 per cent. Both these variants are not very strong and have as much influence as lifestyle habits do. However, the researchers admit the possibility of other genes existing that may be weak by themselves but can collectively influence one’s chances of developing the disease.

In another study, researchers from the University of California, San Francisco, Children's Hospital in California have determined that a protein secreted by gene Olig2 causes gliomas to form. They conducted experiments on mice where they observed that when the protein was prevented from functioning, the gliomas also stopped developing in 91 per cent of the mice. They believe that drugs that target Olig2 will be able to destroy tumor cells without having any negative effect on healthy brain tissue.

Powered by Qumana

Genetics research makes headway

Researchers studying the causes of heart disease made a breakthrough when a recent study identified a gene variant as a cause for heart disease in women. Researchers from Children’s Hospital Oakland Research Institute, the University of Iowa and Roche Molecular Systems held a variant of the gene Leukotriene C4 Synthase (LTC4S) responsible on the basis of a study that began in 1971 and involved 11,377 participants. Various risk factors like weight, cholesterol levels and blood pressure were recorded and analyzed. They found that when those with a variant of gene LTC4S suffer an injury in their blood vessel, there is excessive inflammation, which hampers the repair of the blood vessel. This could lead to heart disease. The researchers are optimistic about their findings making personalized treatments possible.

Meanwhile, an American study has linked a gene IL-12 to asthma. The researchers from the University of Texas Southwestern established that the severity of an asthma bout resulting from the Mycoplasma pneumoniae is dependent on the gene. They arrived at these results after conducting a study on mice wherein normal mice and mice without the gene IL-12 were inoculated with the bacterium. Greater inflammation in the lungs was noticed in mice with the gene. The findings show clearly that there is a need to develop different treatment options for asthma arising out of infections and asthma from allergies.

Researchers from the University of Utah have discovered another probable cause for spinocerebellar ataxia type 5 (SCA5), an inherited disorder. They have determined that when the gene that produces the protein necessary to keep the nerves flexible gets mutated, the disease strikes and the nerves get shattered. But the researchers accept that further investigation is necessary before anything can be conclusively proved.

Powered by Qumana

Genetic research helps unravel several mysteries

Continuing their efforts to study Primary Progressive Aphasia (PPA), American researchers from Northwestern University, Illinois, have zeroed in on a gene mutation as a probable cause for PPA. The researchers observed the samples of two independent families where almost all the members suffered from this disease and compared them with more than 200 control samples. They then concluded that the progranulin gene mutation could cause PPA. The researchers are hopeful that their findings will not only help them understand the causes of this progressive disease but also lead to possible treatments.

In another study, American scientists have discovered genes that will help them better understand autoimmune disorders. It is a known fact that in autoimmune disease, T-cells fail to perform their function of regulating the immune system. Now, researchers from Harvard Medical School, the Dana-Farber Cancer Institute, the Massachusetts Institute of Technology, and the Whitehead Institute for Biomedical Research collaborated on a study and examined the protein Foxp3, a transcription factor. When they scanned the T-cell genome, they found around 30 genes that Foxp3 regulated and even suppressed. The researchers are excited about the possibility that drugs targeting these genes could effectively treat autoimmune disorders.

Meanwhile, in the UK, scientists from the University of Oxford have discovered how to turn off the gene responsible for cell division leading to tumor growth. The research team focused its attention on the ribonucleic acid (RNA) that turned the dihydrofolate reductase (DHFR) gene on and off. The DHFR gene secretes the enzyme that regulates the production of thymine, which, in turn, is essential for cells to divide quickly. The researchers believe that with the development of anti-cancer treatments that hamper the function of this gene, ordinary cells could be stopped from turning into tumors.

Powered by Qumana

New roles of genes unearthed

In a significant collaboration, researchers have discovered a gene which shields some diabetics from severe kidney failure. Researchers from Wake Forest University Baptist Medical Center and University of Heidelberg jointly studied 858 individuals and found that diabetics whose kidneys functioned properly and those without diabetes had the carnosinase 1 gene on chromosome 18 in greater frequency in comparison to the diabetics on dialysis. From these findings, they concluded that the gene plays a vital role in diabetics developing severe kidney failure. They are hopeful that the findings will result in the development of techniques that can prevent kidney failure in diabetics.

Meanwhile, Australian researchers have determined that while APOE4 is responsible for increasing one’s chances of developing Alzheimer’s disease, the gene does not affect cognition. Researchers from the University of Melbourne and Australian National University tested 6,560 participants from different age groups from 20 years to 64 years and found that APOE4 did not adversely affect performance when it came to episodic memory, working memory, mental speed and reaction time. They concluded that APOE4 increases the risk for Alzheimer’s by a process that only enhances the normal rate of cognitive change.

On the other side of the globe, researchers from the Netherlands have linked a gene mutation to alcoholism. Dutch researchers from the University of Maastricht observed 84 men with the A allele and 24 with G allele in the mu-opioid receptor. Each participant was subjected to three-minute tests where his craving, arousal and salivation for water and beer were studied. It was found that those with the G allele had a greater craving when compared to those with A allele. They concluded that this gene was responsible for alcohol dependence. They believe that their findings will help to choose the right treatment plan for alcoholics.

Powered by Qumana