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When a young person develops cancer, doctors most often assume that genetics are the reason, because the patient hasn’t lived long enough to accumulate environmental damage. But it’s been hard to find the faulty DNA behind many tumors. Now, using new genomic technology, scientists have discovered a novel explanation for some testicular cancers, the most common cause of cancer in men under 35. Rather than being triggered by a single gene mutation, the tumors are caused by too many or too few copies of a gene in a person’s cells. These “copy number variations” have been linked to other conditions...

Autism Genome Project Phase 2 results published in Nature Mount Sinai researchers and the Autism Genome Project Consortium (AGP) announced today that they have identified new autism susceptibility genes that may lead to the development of new treatment approaches. These genes, which include SHANK2, SYNGAP1, DLGAP2 and the X-linked DDX53–PTCHD1 locus, primarily belong to synapse-related pathways, while others are involved in cellular proliferation, projection and motility, and intracellular signaling. The findings were published today in Nature by researchers at the Seaver Autism Center for Research and Treatment at Mount Sinai School of Medicine, together with an international consortium of researchers...

Obesity is a disease of excess, but a new study suggests that a few obese patients are actually lacking something--a piece of one of their chromosomes. The loss might remove a gene that helps the body manage blood sugar and appetite. Obesity runs in families, and researchers have identified several genetic variants that seem to boost the odds of becoming obese. However, these variants only explain a minority of cases. In the last decade, researchers have discovered that genetic differences among people can stem from lost or duplicated sections of chromosomes, called copy number variants (CNVs). Because of CNVs, for...

Enlarge ImageGood catch. Using zebrafish, researchers were able to track down the gene that causes this giant mirror carp to have few, large scales. Credit: Oliver Hasselhoff A long-standing question in biology is how evolution tinkers with genes without mucking things up. The prevailing theory is that the genome has copies of critical genes, so that if mutations spoil one, there's a backup. Now researchers have new proof that evolution can work this way. The scientists tracked down a duplicated gene that made possible so-called mirror fish, which have large, reflective scales. "This is a valuable proof of concept...

Really? THE FACTS It is a basic tenet of human biology, taught in grade schools everywhere: Identical twins come from the same fertilized egg and, thus, share identical genetic profiles. But according to new research, though identical twins share very similar genes, identical they are not. The discovery opens a new understanding of why two people who hail from the same embryo can differ in phenotype, as biologists refer to a person’s physical manifestation. The new findings appear in the March issue of The American Journal of Human Genetics, in a study conducted by scientists at the University of Alabama...

Could people one day evolve to eat rich food while remaining perfectly slim and svelte? This may not be so wild a fantasy. It is becoming clear that the human genome does respond to changes in diet, even though it takes many generations to do so. Researchers studying the enzyme that converts starch to simple sugars like glucose have found that people living in countries with a high-starch diet produce considerably more of the enzyme than people who eat a low-starch diet. The reason is an evolutionary one. People in high-starch countries have many extra copies of the amylase gene...

Close window Published online: 24 July 2007; | doi:10.1038/news070723-1 New mutations implicated in half of autism casesDisorder linked to genetic differences between parent and offspring.Heidi Ledford Autistic children display a wide range of different symptoms.HENNY ALLIS / SCIENCE PHOTO LIBRARY Half of all cases of male autism may be caused by spontaneous genetic mutations, say researchers who have studied the genetic patterns of the condition. Offspring who inherit such mutations are at a greater risk of having an autistic child themselves. Autistic people have difficulty relating socially with others and tend to focus obsessively on a narrow set of...