Our understanding of autism continued to deepen and expand in 2015 as an unprecedented number of advances and discoveries were published in scientific journals. These include previously unknown links between the brain and the immune system, as well as reassuring results from the largest comparative study of autism prevalence between vaccinated and unvaccinated children. At the same time, science’s first in-depth study of the autism genome shows that the genetic basis of the condition is far more complex than previously thought. What will our society at large make of these advances? To answer this question, we have selected below the most read and shared findings from autism research in 2015: Autism and disuse: the importance of shared screening In June, researchers reported that this particularly rare language disorder affects nearly 65% of children with autism. The report, published in the journal Developmental and Behavioral Pediatrics, highlights the need to screen for both disorders when evaluating a child for one of the conditions. Disuse disorders include muscles that involve difficulty regulating the production of sounds, so it is important to ensure that specialized treatments are added to autism intervention programs. Half of autism cases traced to rare genetic mutation, study finds In September, investigators reported that at least half of autism stems from one of about 200 genetic mutations found in children that are not present in either parent. The researchers found that many of these mutations completely disrupt the function of genes that are critical to early brain development. With more in-depth research, a new list of “high-impact” autism risk genes may help identify and guide treatment of the many subtypes of autism. Listen up, doctors! Parents can detect autism before it’s diagnosed Zwaigenbaum is one of the world’s leading experts on how to identify autism early. But just this year, his research team found that listening to a more discerning group of experts (parents) would allow doctors like him to make a more accurate diagnosis. Their report, published in the Journal of the American Academy of Child and Adolescent Psychiatry, describes how parents’ concerns when their children were 12 months old helped accurately predict a subsequent autism diagnosis. Large-scale study of autism and parental age finds that children born to teenage mothers are at high risk In June of this year, we received the results of the largest international study of parental age and autism risk. The surprise: a high rate of autism among children born to teenage mothers. The study also confirms previous research showing that the incidence of autism increases each year after parents reach the age of 40. The researchers concluded, ” These results suggest that multiple mechanisms influence the relationship between parental age and risk for autism spectrum disorders.” They also emphasized that while parental age has an impact on the risk of autism, the vast majority of children born to older as well as adolescent parents are not affected. Symptoms of ADHD can delay autism diagnosis by years Symptoms of attention deficit hyperactivity disorder (ADHD) can significantly delay the detection of autism, the researchers report in the journal Pediatrics. In the new study, children who were initially diagnosed with ADHD received their autism diagnosis an average of three years later than children with autism who did not have ADHD. This finding is particularly significant considering that more than half of children with autism also have some symptoms of ADHD to a greater or lesser degree. Because early intervention can lead to a significant improvement in the prognosis of children with autism, the authors urge careful assessment of autism in children with ADHD symptoms. Largest autism genome study to date finds most siblings carry different autism risk genes In January, the largest autism genome study ever conducted revealed that the genetic basis of the disorder is more complex than previously thought: even within the same family, most affected siblings carry different autism-related genes. The study was led by geneticist Stephen Scherer, director of the Autism Speaks MSSNG project, and its report appears as a cover article in the journal Nature Medicine. #4 Researchers call for greater attention to autism-related eating In July, a study of more than 100 children aged 3 to 11 years confirmed that those affected by autism have high rates of anorexia or extreme pickiness in their eating. Their parents also reported experiencing more meal-related behavioral problems, high levels of spousal stress, and a limited variety of foods consumed by the family compared to normally developing children. Researchers are calling on doctors and therapists to pay more attention to eating issues related to autism. The good news: behavioral therapies for autism have been shown to be effective in expanding the scope of the diet and improving the quality of meals consumed by the entire family. Large controlled study of vaccinated and unvaccinated children finds no association between MMR triple vaccine and autism In April, the American Medical Association (JAMA) published the largest-ever study comparing the incidence of autism in vaccinated and unvaccinated children. The survey, which tracked more than 95,000 children, echoed previous findings that there was no link between autism and the MMR vaccine. The study included more than 15,000 unvaccinated children and nearly 2,000 children at high risk for autism because they were born into families already affected by autism The study found a link between autism and epigenetic changes in fathers’ sperm In addition, in April, researchers reported an unusually large number of “epigenetic” changes in DNA in the sperm of fathers of children with autism. epigenetic” changes. Epigenetics involves regulating the timing and orientation of gene activity. The researchers suggest that because epigenetic changes in sperm can be passed on to offspring, they are likely to affect early brain development. As for what causes epigenetic changes, the researchers note that as a result of exposure to toxic chemicals, infections and other environmental hazards during the lifespan, they can accumulate in the cells that produce a man’s sperm. This accumulation with age may help explain why autism is highly prevalent in children with older fathers in the family. Discovery of brain-immune system link could advance understanding of autism In June, neurologists at the University of Virginia reported their discovery of a previously undiscovered system of lymphatic vessels in the membrane that wraps around the brain. Their discovery dramatically changes the scientific understanding of the relationship between the brain and the immune system and may improve the understanding of the role of inflammation in neurological disorders such as autism.