Author Interviews, Autism, Genetic Research, Nature / 12.11.2017
Mechanism Identified Linking ASD and Intellectual Disability, Opening Door To Development of Treatment Options
MedicalResearch.com Interview with:
[caption id="attachment_38196" align="alignleft" width="200"]
Dr-Woo-Yang Kim[/caption]
Woo-Yang Kim, Ph.D
Associate Professor
Department of Developmental Neuroscience
Munroe-Meyer Institute
University of Nebraska Medical Center
Omaha, NE 68198-5960
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Autism impairs the ability of individuals to communicate and interact with others. About 75 percent of individuals with autism also have intellectual disability, which is characterized by significant limitations in cognitive functions and adaptive behaviors. While autism and intellectual disability are currently defined using behavioral criteria, little is known about the neuropathogenesis of these conditions.
Recent genetic studies have reported that haploinsufficiency of ARID1B causes autism and intellectual disability. However, the neurobiological function of ARID1B during brain development is unknown.
Our study investigated the neurobiological role of the gene in brain development. Using genetically-modified mice, we found that Arid1b haploinsufficiency leads to an excitation-inhibition imbalance by reducing the number of GABAergic interneurons in the cerebral cortex. Furthermore, we showed that treatment with a GABAA-receptor positive allosteric modulator rescues ASD-like behavior and cognitive dysfunction in Arid1b-haploinsufficient mice, suggesting an association between lower numbers of GABAergic interneurons and behavioral outcomes.
Our findings suggest a pathogenic mechanism for Autism Spectrum Disorder and intellectual disability.
Dr-Woo-Yang Kim[/caption]
Woo-Yang Kim, Ph.D
Associate Professor
Department of Developmental Neuroscience
Munroe-Meyer Institute
University of Nebraska Medical Center
Omaha, NE 68198-5960
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Autism impairs the ability of individuals to communicate and interact with others. About 75 percent of individuals with autism also have intellectual disability, which is characterized by significant limitations in cognitive functions and adaptive behaviors. While autism and intellectual disability are currently defined using behavioral criteria, little is known about the neuropathogenesis of these conditions.
Recent genetic studies have reported that haploinsufficiency of ARID1B causes autism and intellectual disability. However, the neurobiological function of ARID1B during brain development is unknown.
Our study investigated the neurobiological role of the gene in brain development. Using genetically-modified mice, we found that Arid1b haploinsufficiency leads to an excitation-inhibition imbalance by reducing the number of GABAergic interneurons in the cerebral cortex. Furthermore, we showed that treatment with a GABAA-receptor positive allosteric modulator rescues ASD-like behavior and cognitive dysfunction in Arid1b-haploinsufficient mice, suggesting an association between lower numbers of GABAergic interneurons and behavioral outcomes.
Our findings suggest a pathogenic mechanism for Autism Spectrum Disorder and intellectual disability.


















David Beversdorf, M.D.
Associate professor in the departments of radiology, neurology and psychological sciences
University of Missouri and
Missouri University Thompson Center for Autism and Neurodevelopmental Disorders
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Beversdorf: Our previous work had demonstrated in retrospective surveys a higher incidence of prenatal psychosocial stress exposure during the late 2nd and early 3rd trimester in pregnancies where the offspring had developed autism spectrum disorder (ASD). This had been confirmed in other studies, including a study examining the timing of exposure to tropical storms during pregnancy. However, not everyone exposed to stress during pregnancy has a child with ASD, so we began to look at genetic risk for augmented stress reactivity. This initial exploration involved examination of the interaction between stress exposure during ASD-associated pregnancies and the maternal presence of variations in one gene well known to affect stress reactivity. Variations in this gene were also targeted as they have been associated with ASD in some studies. We found in two independent groups of patients (one in Missouri, one in Ontario, Canada) that maternal presence of at least one copy of the stress-susceptible variant of this gene is associated with the link between maternal stress exposure during this time window of pregnancy and subsequent development of ASD in the offspring.
Dr. Steven Hicks[/caption]
Steven Daniel Hicks, M.D., Ph.D.
Penn State Hershey Medical Group Hope Drive, Pediatrics
Hershey, PA 17033
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Hicks: This research was inspired by results of the CHARGE study (examining environmental influences on autism) which showed that specific pesticides (including pyrethroids) increased the risk of autism and developmental delay, particularly when mothers were exposed in the 3rdtrimester.
We recognized that the department of health sprayed pyrethroids from airplanes in a specific area near our regional medical center every summer to combat mosquito borne illnesses. We asked whether children from those areas had increased rates of autism and developmental delay. We found that they were about 25% more likely to be diagnosed with a developmental disorder at our medical center than children from control regions without aerial spraying of pyrethroids.
