Author Interviews, Autism, Genetic Research, Schizophrenia, UCLA / 26.05.2017
Gene Dosage at 22q11.2 Helps Determine Schizophrenia vs Autism Brain Differences
MedicalResearch.com Interview with:
[caption id="attachment_34886" align="alignleft" width="120"]
Dr. Bearden[/caption]
Carrie Bearden, Ph.D.
Professor, Departments of Psychiatry and Biobehavioral Sciences and Psychology
Semel Institute for Neuroscience and Human Behavior
University of California, Los Angeles
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: A 22q11.2 deletion confers the highest known genetic risk for schizophrenia, but a duplication in the same region is strongly associated with autism and is less common in schizophrenia cases than in the general population.
Thus, we became interested in trying to understand whether there were differences in brain development that might predispose to one condition vs. the other.
Dr. Bearden[/caption]
Carrie Bearden, Ph.D.
Professor, Departments of Psychiatry and Biobehavioral Sciences and Psychology
Semel Institute for Neuroscience and Human Behavior
University of California, Los Angeles
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: A 22q11.2 deletion confers the highest known genetic risk for schizophrenia, but a duplication in the same region is strongly associated with autism and is less common in schizophrenia cases than in the general population.
Thus, we became interested in trying to understand whether there were differences in brain development that might predispose to one condition vs. the other.













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.





Dr. Richard Deth[/caption]
MedicalResearch.com Interview with:
Dr. Richard Deth PhD
Professor of Pharmacology
Department of Pharmaceutical Sciences
Nova Southeastern University
Medical Research: What is the background for this study?
Dr. Deth: Vitamin B12 plays a crucial role in regulating and promoting methylation reactions (the attachment of a carbon atom to molecules), including DNA methylation. Recent research has identified methylation of DNA and consequential changes in gene expression as crucial factors in brain development, as well as in memory formation and maintenance of brain function during aging. More specifically, the cause(s) of neurodevelopmental disorders such as autism remain obscure, although numerous studies have demonstrated oxidative stress and low plasma levels of the antioxidant glutathione (GSH) in autism.
Medical Research: What are the main findings?
Dr. Deth: We found that brain levels of vitamin B12, especially the methylation-regulating form known as methylB12, decrease significantly with age, even though blood levels don’t show a similar decrease. Importantly, much lower levels of methylB12 were found in subjects with autism and schizophrenia compared to normal subjects of a similar age. Animal studies showed that impaired GSH formation is associated with decreased brain B12 levels.
Dr. Diana Schendel[/caption]
MedicalResearch.com Interview with:
Diana Schendel, Professor MSO
Department of Public Health
Institute of Epidemiology and Social Medicine and
Department of Economics and Business National Centre for Register-based Research
Aarhus University
Denmark
Medical Research: What is the background for this study? What are the main findings?
Dr. Schende: Elevated mortality has been reported in persons with autism spectrum disorder (ASD), especially with comorbid epilepsy and intellectual disability. The effect of comorbidity on the risk for mortality in ASD, however, has not been rigorously examined in large, population-based studies. Our study aim was to investigate ASD mortality patterns overall and to assess the specific effects of comorbid mental, behavioral, and neurologic disorders on ASD mortality into young adulthood. Our study comprised a nation-wide Danish cohort of 1.9 million children of whom 20,492 were diagnosed with ASD. We observed 68 deaths in persons with ASD; 83% of the persons with ASD who died had comorbid mental/behavioral or neurologic disorders. The risk for mortality was two-fold higher in persons with
Dr. Chugani[/caption]
MedicalResearch.com Interview with:
Diane C. Chugani, PhD
Director, Nemours Neuroscience Research
Nemours—AI DuPont Hospital for Children
Wilmington, DE 19803
Medical Research: What is the background for this study? What are the main findings?
Dr. Chugani: This clinical trial was performed at 5 sites throughout the country and was lead by our team at Wayne State University and Children’s Hospital of Michigan in Detroit. The study was sponsored by the National Institutes of Health through an Autism Centers of Excellence Network grant. Based upon our previous PET scanning studies showing low serotonin synthesis in the brains of young children with autism, we tested whether the serotonin-like drug buspirone would be beneficial in treating young children with Autism Spectrum Disorder. We found that low doses of buspirone were effective in reducing repetitive behaviors with no significant side effects in this group of children.