Group items tagged

Purpose of review: Autism is a biologically based disorder of brain development. Genetic factors - mutations, deletions, and copy number variants - are clearly implicated in causation of autism. However, they account for only a small fraction of cases, and do not easily explain key clinical and epidemiological features. This suggests that early environmental exposures also contribute. This review explores this hypothesis. Recent findings: Indirect evidence for an environmental contribution to autism comes from studies demonstrating the sensitivity of the developing brain to external exposures such as lead, ethyl alcohol and methyl mercury. But the most powerful proof-of-concept evidence derives from studies specifically linking autism to exposures in early pregnancy - thalidomide, misoprostol, and valproic acid; maternal rubella infection; and the organophosphate insecticide, chlorpyrifos. There is no credible evidence that vaccines cause autism. Summary: Expanded research is needed into environmental causation of autism. Children today are surrounded by thousands of synthetic chemicals. Two hundred of them are neurotoxic in adult humans, and 1000 more in laboratory models. Yet fewer than 20% of high-volume chemicals have been tested for neurodevelopmental toxicity. I propose a targeted discovery strategy focused on suspect chemicals, which combines expanded toxicological screening, neurobiological research and prospective epidemiological studies.

"A large study from Children's Hospital Boston and the Boston-based Autism Consortium finds that a genetic test that samples the entire genome, known as chromosomal microarray analysis, has about three times the detection rate for genetic changes related to autism spectrum disorders (ASDs) than standard tests. Publishing in the April issue of Pediatrics (and online March 15), the authors urge that CMA become part of the first-line genetic work-up for ASDs."

(CNN) -- A now-retracted British study that linked autism to childhood vaccines was an "elaborate fraud" that has done long-lasting damage to public health, a leading medical publication reported Wednesday.

Today, it is estimated that one in every 110 children is diagnosed with autism, making it more common than childhood cancer, juvenile diabetes and pediatric AIDS combined.

Some argue that these genes bring benefits - mental illness and genius have a long-standing link - but archaeologist Penny Spikins at the University of York, UK, goes further. She believes that mental illness and conditions such as autism persist at such high levels because in the past they were advantageous to humanity. "I think that part of the reason Homo sapiens were so successful is because they were willing to include people with different minds in their society - people with autism or schizophrenia, for example."

A new study of twins released online on Monday marked an important shift in thinking about the causes of autism.

"New research from Case Western Reserve University and University of Toronto neuroscientists finds that the brains of autistic children generate more information at rest - a 42% increase on average. The study offers a scientific explanation for the most typical characteristic of autism - withdrawal into one's own inner world. The excess production of information may explain a child's detachment from their environment. "