In Nature a group of researchers from Denmark and Iceland report the results of their studies of mutation rates of Icelandic parent-child groups. They found that the level of new mutations, called a “de novo mutations,” in their samples when father’s average age was 29.7 was 1.20?X?10?8 per nucleotide per generation, but that number increases by two every year. In round numbers one might estimate that at about 20 years of age a father’s single sperm cell could carry 25 new spontaneous mutations, but at 40 years of age it might carry more than 65.
Continue reading ‘Nature: De novo mutations, autism, and schizophrenia, redux’
In articles published online by Nature, Professors Stephan Sanders and colleagues and Brian J. O’Roak his colleagues reported additional evidence that rare mutations contribute to risk for Autism. By analyzing genetic material from parents who had children with Autism, the researchers were able to focus on differences in specific genes, what changed from one generation to the next. One team, working in the research lab of Professor Matthew State at Yale University, found strikingly unusual matches for a specific mutation at SCN2A. The other team, under the direction of Professor Evan Eichler at the University of Washington, found several candidates (including SCN1A) and a strong (4 to 1) relationship for older fathers.
Continue reading ‘De novo mutations and Autism redux’
In Pediatrics Professor Sally Ozonoff and her colleagues of the Baby Siblings Research Consortium have reported data indicating a substantially higher risk for Autism among siblings than had been previously found. Based on data from studies in the 1980s, estimates of the risk of Autism in a child given that an older sibling had Autism were in the range of 3 to 5%, the Consortium found that the risk may be as great as four times higher than that, perhaps as high as 20%.
The researchers in the Consortium used very careful methods in which they found 664 later-born, biological siblings of a child with Autism when that younger sibling was, on average, about 8 months old. They followed the development of the siblings and assessed whether they had the symptoms of Autism when they were 36 months old. They found almost 19% had scores above the cut-off for Autism. The risk for Autism was even greater for boys and when more than one older sibling had Autism.
Continue reading ‘Little sibs of children with ASD have greater risk of Autism’
The Council for Children with Behavioral Disorders (CCBD) is hosting a meeting at the Sheraton Norfolk Waterside Hotel in Norfolk (VA, US) and the registration deadline is tomorrow, 3 February 2011. CCBD has reduced the fees and there are spcial discounted rates for teams of three or more attendees.
Continue reading ‘CCBD conference 2011’
Brian Deer, the journalist who has doggedly pursued the story about a link between materials in vaccines and the onset of childhood Autism proposed by Dr. Andrew Wakefield and colleagues in the late 1990s, has published details explaining why he considers the original research establishing that link to have been fraudulent. In the first of a series of articles appearing in the prestigious British Medical Journal, Mr. Deer reports the results of his efforts to locate and interview the originally anonymous parents of the children included in the study by Dr. Wakefield et al.—which was published in the Lancet and then retracted—and it is sure to generate lots of heat, and perhaps a little bit of light.
Continue reading ‘Deer’s fraud case in BMJ’
The sugar-makes-kids-hyper hypothesis is still false. Dan Willingham stuck another fork in it. Roasty-toasty. All done. Fizzle.
Now, I’m not advocating a high-fructose, feed-’em-soda-and-sweets diet, to be sure. It’s just that folks need to disabuse themselves of the popular myth that children’s levels of behavioral activity are governed by consumption of sucrose (whether from sugar cane or sugar beet).
Professor Willingham, who pops bubbles with the best of them, lanced this one in his guest post, “The Answer Sheet: How sugar really affects kids.” The evidence is basically the same as what I covered in the mid 1990s under the title “Sugar High?.”
Writing in the American Journal of Psychiatry, John Gilmore and colleages reported that the size and structure of the brains of newborn boys—but not girls—who are at risk for developing schizophrenia differ from those of their peers. Using multiple scanning methods at different times during gestation and infancy, the researchers compared the brains of offspring of mothers who have schizophrenia to the offspring of mothers who do not have schizophrenia; they found that high-risk boys had larger brains and larger lateral ventricles than baby boys whose mothers did not have psychiatric illness.
Because the risk of developing schizophrenia is much greater for close relatives of schizophrenics, the differences between the groups provides a strong indicator of later potential development of disease. Professor Gilmore wondered “Could it be that enlargement is an early marker of a brain that’s going to be different?”
Continue reading ‘Brain features associated with neonatal risk for schizophrenia’