A new genetic study shows even siblings with autism often have very different DNA mutations from one another a finding that strengthens the evidence that autism is often just genetic bad luck. The deep dive into the DNA of 170 people with autism spectrum disorder shows that more than 69 percent of brothers and sisters with autism had different DNA mutations underlying their disorders, Dr. Stephen Scherer of The Hospital for Sick Children in Toronto, Canada and colleagues found. "It's random mutation in these families. It just happens to be lightning striking twice," Scherer said. "It just happens to be lightning striking twice." The findings, published in the journal Nature Medicine, add to other research that shows "autism" is a broad term for a range of developmental disorders that are barely related to one another. The catchall name could be making it seem like one disorder is affecting many kids, when in fact it's a range of conditions. "It is largely just a random effect," Scherer said. "Everybody in the population accumulates new mutations in the genome when they are conceived." Autism spectrum disorder can range from the mild social awkwardness, including Asperger's syndrome, to profound mental retardation, debilitating repetitive … Continue reading →

Less than a third of autistic brothers and sisters share the same genetic risk factors. Photograph: Jane Bown A major study of autism in families has found that brothers and sisters who have the condition often carry different genetic risk factors that make them prone to the disorder. Research on 85 families found that siblings with autism had the same genetic risk factors less than one third of the time. In nearly 70% of cases, tests on the siblings revealed little or no overlap in the mutations known to contribute to the condition. The findings challenge the presumption that the same genetic risk factors are at work when autism runs in families. We knew that there were many differences in autism, but our recent findings firmly nail that down, said Stephen Scherer at the University of Toronto. This means we should not be looking just for suspected autism-risk genes, as is typically done in diagnostic genetic testing, Scherer added. Instead, he said a full assessment of a persons genome was needed if genetic information was ever going to inform their treatment. In years of research, scientists have identified more than 100 genetic mutations that seem to contribute to autism, suggesting … Continue reading →

IMAGE:Professor Dimitrios Stamou heads a team specializing in investigating single cells and cell membranes along with a multidisciplinary team from Bio-Nanotechnology and Nanomedicine Laboratory, Nano-Science Center, Department of Chemistry, University... view more Credit: Photo: Jes Andersen/University of Copenhagen. The findings of Professor Dimitrios Stamou, Post Doc Jannik Bruun Larsen and a multidisciplinary team from Bio-Nanotechnology and Nanomedicine Laboratory, Nano-Science Center, Department of Chemistry are published under the title "Membrane curvature enables N-Ras lipid anchor sorting to liquid-ordered membrane phases" in the highly respected journal Nature Chemical Biology. Ras-proteins inhabit the interior wall of each and every cell in the human body. Their role is to activate cell division or cell growth, so cancers develop if the protein starts to permanently trigger cells to grow and split: A process known as misregulation. Ras misregulates if it misses its correct location on the cell wall; its membrane. What Stamou and Larsen discovered is that Ras cannot reach its designated location if the membrane has the wrong shape, explains Professor Dimitrios Stamou. "If the curvature of the cell is right, Ras goes to the right place. If the membrane is too straight or too bent, it does not. And Ras is very much … Continue reading →