A quarterly publication of the Autism Research Institute

The Autism Research Review International is quarterly publication of the Autism Research Institute

Spring, 2019 | Number 2, Volume 33

Gene linked to autism also shown to affect the gut

Individuals with autism spectrum disorders (ASD) frequently suffer from gastrointestinal problems as well, and new research suggests that these GI problems may stem from the same gene mutations that cause brain and behavioral symptoms.

In a 2003 study, one group of researchers identified a specific gene mutation that causes some cases of ASD. The mutation alters the “Velcro” between neurons which keeps them in close contact. This study involved two brothers with ASD who also had GI problems.

Now, a separate group of researchers has extended this work by conducting a series of studies on the structure and function of the gut in mice that have the same gene mutation. They report that this mutation affects gut contractions, the number of neurons in the small intestine, the speed at which food moves through the small intestine, and the gut’s responses to the neurotransmitter GABA. In addition, the researchers detected significant differences in the gut microbiomes of mice with the mutation and control mice, even though both groups were kept in identical environments. 

While the specific mutation the researchers studied is rare, they note that more than 150  autism-associated gene mutations alter neuronal connections. Study coauthor Elisa Hill-Yardin says, “The link we’ve confirmed suggests a broader mechanism, indicating that the mutations that affect connections between neurons could be behind the gut problems in many patients.”

Hill-Yardin says the group’s discoveries could someday lead to the development of therapies specifically designed to work on neurotransmitters in the gut. She adds, “Another promising path for future research is investigating how gene mutations in the nervous system relate to microbes in the gut. We know these microbes interact with the brain via the gut-brain axis, so could tweaking them improve mood and behavior? While this wouldn’t reverse the gene mutation, we might be able to tone down its effects and make a real difference in the quality of life for people with autism and their families.”


Citations

“Gastrointestinal dysfunction in patients and mice expressing the autism-associated R451C mutation in neuroligin-3,” Suzanne Hosie, Melina Ellis, Mathusi Swaminathan, Fatima Ramalhosa, Gracia O. Seger, Gayathri K.Balasuriya, Christopher Gillberg, Maria Råstam. Leonid Churilov, Sonja J. McKeown, Nalzi Yalcinkaya, Petri Urvil, Tor Savidge, Carolyn A. Bell, Oonagh Bodin, Jen Wood, Ashley E. Franks, Joel C. Bornstein, and Elisa L. Hill-Yardin, Autism Research, May 22, 2019 (free online). Address: Elisa L. Hill-Yardin, School of Health and Biomedical Sciences, RMIT

University, 225-245 Clements Drive, Bundoora, Victoria 3083 Australia, [email protected]

—and—

“Research confirms gut-brain connection in autism,” news release, RMIT University, May 30, 2019.