With the heat of summer hitting its peak and starting to break around the country as families get ready for the school year, this week’s look at autism in the news highlights three recent studies that look to environmental, genetic, and maternal factors as means to better understanding the possible causes behind autism.
We want to provide the best education possible at the Autism Academy, that means finding out everything possible about autism. To be able to support our children with autism we need to continue educating each other to learn everything about autism research.
First up, as research into determining possible environmental causes behind autism has decreased with more researchers looking at genetics and the brain, a new study renewed the focus on the environment when researchers found that exposure to high levels of PCBs while still in the womb increases children’s chances of developing autism. PCBs, or polychlorinated biphenyls, are man-made chemicals once used in a wide range of products, from electrical appliances to fluorescent lighting.
Although these chemicals have been banned since the 1970s when politicians heeded the public’s concern about the health risks posed by PCBs entering the water and environment. However, they do not break down easily, leaving many parts of the country still reporting high rates of PCBs in the environment. The study itself discovered that when pregnant mothers were found to have substantial levels of PCBs in their blood, their children are 80 percent more likely to develop autism. As one researcher put it, this new study adds another “puzzle piece” to the autism puzzle, which many believe to be a combination of environmental factors and genetic susceptibility.
In other research news, there have been a number of new studies looking at the genetics of siblings with autism to determine how their genes differ. The team of researchers UCLA found that in families with more than one sibling with autism, there is a considerable amount of difference in the types of gene variations found. The genetic risk for autism is extremely complex,” said lead researcher Dr. Daniel Geschwind. He is a professor of human genetics at the David Geffen School of Medicine at University of California, Los Angeles. “Even in ‘multiplex’ families [where more than one child has autism], it’s not as obvious as thought,” he said.
Studies of siblings have proven particularly fruitful due to the fact that when a family has one child with autism, they have a one-in-five chance of giving birth to another child with autism.
In particular, they looked at gene alterations known as copy-number variants (CNVs), which can lead to the gain or loss of normal DNA. CNVs can be inherited from parents due to defects in the parents’ sperm or eggs. As multiple CNVs have been tied to autism, the researchers discovered that in families with more than one child with autism, inherited CNVs played a bigger role in autism risk than non-inherited versions.
While this outcome was expected, what surprised scientists is that when one sibling has a CNV known to be linked to autism, the other sibling tended not to have the same gene variant. In theorizing potential reasons as to why this is, one argument is that those siblings without a similar CNV likely have a harder-to-pinpoint genetic mutation that scientists have yet to discover.
Finally, in our last study of the week, a recent meta-analysis that looked at 15 different studies found that mothers who develop an infection while pregnant are 12 percent more likely to have a child later diagnosed with autism. However, this rate varied greatly depending on the infection type, location, timing, and severity; mothers who were hospitalized due to an infection, the autism risk rises to 30 percent. It also increases the later during a pregnancy that an infection occurs.
By continuing research on autism and educating our children we’ll figure out where autism originates from. Continue reading our blog about autism to learn more about autism research, activities, and more topics. If you are interested in sending your child to a school for children with autism, contact us.