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 [1], 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 [2], 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.

Earlier this month at the 58th Annual Meeting of the American Society of Human Genetics in Philadelphia, researchers reported the results of two genome-wide genetic analyses, identifying five significant loci that contribute to autism susceptibility, three of which have not been reported previously [1], as well as a novel association of genetic variation on chromosome 5 with autism [2].

Today, one in 150 children is diagnosed with autism. In fact, more children will be diagnosed with autism this year than with cancer, diabetes and AIDS combined [3]. Autism is a brain development disorder that impairs a person’s ability to communicate or interact socially. The disorder is associated with restricted and repetitive behavior. While there is no cure for autism, with appropriate treatment and education, many children can learn and develop. The genetics of autism are the focus of much study, as it is unclear whether the disorder is due to rare mutation(s) or multigene interactions.