A gene mutation responsible for the most common form of inherited colon cancer is older and more common than formerly believed, according to a recent study.

The findings provide a better understanding of the spread and prevalence of the American Founder Mutation, a common cause in North America of Lynch syndrome, a hereditary cancer syndrome that greatly increases a person’s risk for developing cancers of the colon, uterus and ovaries.

The same investigators discovered the mutation in 2003. That research identified nine families with the mutation and concluded that a German immigrant couple brought the mutation to North America in 1727. … Continue Reading »

Some kids with autism may have a genetic defect that affects the muscles, according to research that will be presented at the American Academy of Neurology 60th Anniversary Annual Meeting in Chicago, April 12–19, 2008.

The study looked at 37 children with autism spectrum disorders who were evaluated for mitochondrial disease, which causes muscle weakness and prevents a child from being able to participate in physical activities and sports. Mitochondrial disease occurs when genetic mutations affect the mitochondria, or the part of the cell that releases energy. … Continue Reading »

The discovery of a gene for a rare form of inherited iron deficiency may provide clues to iron deficiency in the general population – particularly iron deficiency that doesn’t respond to iron supplements - and suggests a new treatment approach. The finding was published online by the journal Nature Genetics on April 13.

Iron deficiency is the most common nutritional deficiency and the leading cause of anemia in the United States.(1) Most cases are easily reversed with oral iron supplements, but over the years, Mark Fleming, MD, DPhil, interim Pathologist-in-Chief at Children’s Hospital Boston, and pediatric hematologist Nancy Andrews, MD, PhD, formerly of Children’s and now Dean of Duke University School of Medicine, had been referred a number of children with iron deficiency anemia who didn’t respond to oral supplements, and only poorly to intravenous iron. … Continue Reading »

A tiny variation in a gene known as CHI3L1 increases susceptibility to asthma, bronchial hyperresponsiveness and decline in lung function, researchers report early online in the New England Journal of Medicine. (The printed version will appear in the April 17 issue). The gene variant causes increased blood levels of YKL-40, a biomarker for asthma. A slightly different version of the genetic variation lowers YKL-40 levels and protects against asthma.

Although the original discovery came from a study of a genetically isolated population, the Hutterites of South Dakota, the researchers were able to confirm the same connections between the CHI3L1 variations, YKL-40 levels and asthma susceptibility in three genetically diverse Caucasian populations from Chicago; Madison, Wisconsin; and Freiberg, Germany.

This gene, “may have important implications in the early identification of, susceptibility to, and prevention and treatment of asthma,” said Elizabeth G. Nabel, M.D., director, the National Heart, Lung, and Blood Institute. … Continue Reading »

An international team that included scientists from the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health (NIH), today reported it has identified six more genetic variants involved in type 2 diabetes, boosting to 16 the total number of genetic risk factors associated with increased risk of the disease. None of the genetic variants uncovered by the new study had previously been suspected of playing a role in type 2 diabetes. Intriguingly, the new variant most strongly associated with type 2 diabetes also was recently implicated in a very different condition: prostate cancer.

The unprecedented analysis, published today in the advance online edition of Nature Genetics, combined genetic data from more than 70,000 people. The work was carried out through the collaborative efforts of more than 90 researchers at more than 40 centers in Europe and North America.

“None of the genes we have found was previously on the radar screen of diabetes researchers,” said one of the paper’s senior authors, Mark McCarthy, M.D., of the University of Oxford in England. “Each of these genes, therefore, provides new clues to the processes that go wrong when diabetes develops, and each provides an opportunity for the generation of new approaches for treating or preventing this condition.” … Continue Reading »

Persons with a certain type of homozygosity (having two identical copies of the same gene, one inherited from each parent), may have a greater predisposition to cancer, according to a study in the March 26 issue of JAMA.

In previous research, the authors observed a low frequency of germline (those cells of an individual that have genetic material that could be passed to offspring) heterozygosity (possessing two different forms of a particular gene, one inherited from each parent) in cancer patients compared with controls, raising the question whether homozygosity could play a role in cancer predisposition. “Homozygosity is common in humans and extended homozygote tracts have been described in several studies. Cancer susceptibility genes are also numerous in the genome. These facts together increase the likelihood that homozygosity might occur in the loci [the specific site of a particular gene on its chromosome] of cancer susceptibility genes. One can then hypothesize that germline homozygosity at these loci may somehow contribute to cancer predisposition,” the researchers write. … Continue Reading »