Some children who are accurately diagnosed in early childhood with autism lose the symptoms and the diagnosis as they grow older, a study supported by the National Institutes of Health has confirmed . The research team made the finding by carefully documenting a prior diagnosis of autism in a small group of school-age children and young adults with no current symptoms of the disorder.
According to an article in the Morbidity and Mortality Weekly Report, a publication of the U.S. Centers for Disease Control and Prevention (CDC), the prevalence of autism spectrum disorder (ASD) is higher than ever . The CDC periodically surveys the prevalence of ASD, looking during each surveillance period at the percentage of 8-year-old children who have current ASD diagnoses. In 2000, a survey of children born in 1992 revealed that one in 150 had ASD. These numbers have been steadily climbing, such that the most recent survey — completed in 2008 and surveying children born in 2000 — indicates that one in 88 children has ASD. The numbers are even more disturbing for male children, who have an ASD prevalence of one in 54.
While the alleged link between vaccines — particularly the measles, mumps, and rubella (MMR) vaccine — and autism has been thoroughly discredited in more than 20 well-conducted studies of vaccine side effects , fears about the side effects of vaccination nevertheless remain a major factor influencing the healthcare decisions some parents make. This has led to an increasing percentage of unvaccinated children in the U.S. in recent years, which in turn has ramifications for public health.
A recent study published in the Journal of the American Medical Association, however, sheds new light on physiological roots — though not causes — of autism , and in so doing rules out the potential for any link between vaccination and development of the disease. In the study, researchers examined the size and number of neurons in the prefrontal cortex of young deceased males with autism, and compared the data to that obtained from young deceased non-autistic males.
The largest and most rigorous twin study of its kind to date has found that shared environment influences susceptibility to autism more than previously thought.
The study, supported by the National Institutes of Health, found that shared environmental factors — experiences and exposures common to both twin individuals — accounted for 55% of strict autism and 58% of more broadly defined autism spectrum disorders (ASD). Genetic heritability accounted for 37% of autism and 38% of ASD. Random environmental factors not shared among twins play a much smaller role.
Autism Spectrum Disorder (ASD) researchers now can use data from over 10,000 participants enrolled in ASD studies. The National Database for Autism Research (NDAR), created by the National Institutes of Health, recently made the data available. Researchers can now use the NDAR portal to perform queries that simultaneously yield results from multiple datasets. The portal was designed to provide tools to define and standardize data collected by different laboratories under different protocols. It was also built to ensure a collaborative approach and open data access to the whole ASD research community.