Prevalence of Autism Spectrum Disorders Lower in Black and Hispanic Children

MedicalResearch.com Interview with:

Maureen Durkin, PhD, DrPH Professor and Interim Chair Department of Population Health Sciences University of Wisconsin School of Medicine and Public Health Madison, WI

Prof. Durkin

Maureen Durkin, PhD, DrPH
Professor and Interim Chair
Department of Population Health Sciences
University of Wisconsin School of Medicine and Public Health
Madison, WI 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Previous studies of the prevalence of autism spectrum disorder (ASD) among children in the U.S. have found two consistent patterns.  One is a higher prevalence among white non-Hispanic children than among black non-Hispanic or Hispanic children.  The other is a positive socioeconomic gradient, meaning that ASD prevalence in the U.S. is found to increase with increasing income and other indicators of socioeconomic status.

One of the findings of this new study is that the racial and ethnic differences in autism spectrum disorder prevalence are not explained by socioeconomic factors, because even after adjusting for socioeconomic factors, ASD prevalence was found to be significantly lower in black and Hispanic children than in white non-Hispanic children.  Another finding is that the gap in ASD prevalence between children of high and low socioeconomic status did not change over time between 2002 and 2010, though the overall prevalence of ASD more than doubled during this period.

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Multivitamins in Pregnancy May Be Associated With Lower Autism Risk

MedicalResearch.com Interview with:
Elizabeth DeVilbiss, PhD MPH
Dornsife School of Public Health
Drexel University

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Unfortunately, not much is known about how diet during pregnancy affects autism risk.  There have been studies in recent years about varied aspects of diet during pregnancy and autism risk involving multivitamins, iron, folic acid, vitamin D, and more, but the evidence is still inconclusive.

After adjusting for several potentially influencing factors in both mothers and children, we found that multivitamin use, with or without additional iron and/or folic acid, was associated with a lower likelihood of child autism spectrum disorder with intellectual disability relative to mothers who did not use folic acid, iron, and multivitamins.

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Autism Spectrum Disorder Found To Be Highly Heritable

MedicalResearch.com Interview with:

Sven Sandin, PhD Assistant Professor Department of Psychiatry Icahn School of Medicine at Mount Sinai New York, NY 10029

D. Sandin

Sven Sandin, PhD Assistant Professor
Department of Psychiatry
Icahn School of Medicine at Mount Sinai
New York, NY 10029 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: In 2014, we estimated the heritability of autism to be approximately 50%. Motivating us then was the lack of studies in autism heritability using population based and the findings from a twin-study in California finding the heritability to be substantially lower than the 80-90% estimated in previous studies. Since then continued efforts working with the questions on heritability and environmental factors for autism we found differences between different methods and different samples. When we went back to our previous data we found the heritability of autism to be higher than previously estimated. We found that our previous result was due to a methodological artifact where the adjustment for differences in follow-up used in that manuscript underestimated the heritability. Using methods used in other heritability studies the heritability is now estimated to 84%. Importantly, as previously concluded, there is no support for any ‘shared environmental factors’ in the etiology of autism, e.g. environmental factors shared between two siblings.

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Folic Acid May Reduce Risk of Autism Associated With Pesticide Exposure During Pregnancy

MedicalResearch.com Interview with:

Rebecca J. Schmidt, M.S., Ph.D.  Assistant Professor, Public Health Sciences UC Davis California

Dr. Schmidt

Rebecca J. Schmidt, M.S., Ph.D. 
Assistant Professor, Public Health Sciences
UC Davis California

MedicalResearch.com: What is the background for this study?

Response: Maternal folic acid taken near conception has been linked to reduced risk for autism in the child in previous studies.

Separate studies show that exposure to pesticides during pregnancy is associated with increased risk for autism.

Animal studies demonstrate that folic acid and other B-vitamins can attenuate effects of certain environmental contaminants, including pesticides.

This case-control study examined combined maternal folic acid and pesticide exposures in relation to autism in the child.

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Association of Brain White Matter Structure With Autism Spectrum Disorder and ADHD

MedicalResearch.com Interview with:

Dr. Adriana Di Martino, MD Associate Professor, Department of Child and Adolescent Psychiatry NYU Langone Health

Dr. Di Martino

Dr. Adriana Di Martino, MD
Associate Professor, Department of Child and Adolescent Psychiatry
NYU Langone Health

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: While there has been an increased awareness of the co-occurrence of symptoms of Attention Deficit/Hyperactivity Disorder (ADHD) in children with a primary diagnosis of ASD, only recently has there been an appreciation that a substantial proportion of children with ADHD may also have ASD traits. These symptom domains overlap pose a challenge for accurate recognition and targeted treatments, yet their underlying mechanisms have been unknown.

With more traditional diagnostic group comparisons we detected a significant influence of ASD on white matter organization, but our analyses of the severity of symptoms across individuals revealed an association between autistic traits and white matter organization, regardless of the individual’s diagnosis. These findings were mostly centered around the corpus callosum, a structure that enables communication between the left and right cerebral hemispheres.

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Study Finds Diet Not Connected to GI Problems in Children With Autism

MedicalResearch.com Interview with:

Bradley James Ferguson, PhD University of Missouri School of Medicine

Dr. Ferguson

Bradley James Ferguson, PhD
University of Missouri School of Medicine 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Many individuals with autism spectrum disorder (ASD) have gastrointestinal problems, such as constipation, irritable bowel syndrome and abdominal pain, but the cause of these GI issues is not currently known. Previous research from our laboratory showed a significant positive relationship between cortisol levels and GI problems, especially for constipation. However, it is possible that other factors such as diet may affect GI functioning, especially since many children have altered diets. This study examined 32 different nutrients in the children’s diets, as assessed by a food frequency questionnaire that assessed the participant’s diet over the past month, and how each nutrient was related to upper and lower GI tract symptom scores over the past month created from the Questionnaire on Pediatric Gastrointestinal Symptoms – Rome III. The results showed no significant relationships between any of the nutrients and GI symptoms, suggesting that diet was not associated with GI symptoms in this sample.

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MRI At Six Months Can Predict Which High Risk Babies Will Develop Autism

MedicalResearch.com Interview with:

Joseph Piven, MD The Thomas E. Castelloe Distinguished Professor of Psychiatry UNC School of Medicine Director of the Carolina Institute for Developmental Disabilities Co-senior author of the study

Dr. Piven

Joseph Piven, MD
The Thomas E. Castelloe Distinguished Professor of Psychiatry
UNC School of Medicine
Director of the Carolina Institute for Developmental Disabilities
Co-senior author of the study

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Babies with older siblings with autism are at an increased risk (20%) of getting autism over the general population (1%).  Infants who later are diagnosed with autism don’t have any of the stigmata of autism in the first year of life. The symptoms of autism unfold in the first and particularly in the second year of life and beyond.

We have evidence to support the idea that behavioral symptoms of autism arise from changes in the brain that occur very early in life. So we have employed MRI and computer analyses to study those early brain changes and abnormalities in infancy to see if early brain changes at 6 months of age can predict whether babies at high-risk of developing autism will indeed develop the condition at age two.

For this particular study, we used data from MRIs of six-month olds to show the pattern of synchronization or connection across brain regions throughout the brain and then predict which babies at high familial risk of developing autism would be most likely to be diagnosed with the condition at age two.

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Baby Teeth Can Expose Toxic Levels of Minerals Associated With Autism

MedicalResearch.com Interview with:

Manish Arora, PhD Associate Professor Environmental Medicine & Public Health Icahn School of Medicine at Mount Sinai

Dr. Arora

Manish Arora, PhD
Associate Professor
Environmental Medicine & Public Health
Icahn School of Medicine at Mount Sinai

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Autism has both genetic and environmental risk factors. Our aim was to study if exposure to toxic metals, such as lead, or disruptions in the uptake of essential nutrient elements such as manganese or zinc would be related to autism risk. Furthermore, we were interested in not only understanding how much exposure had taken place but also which developmental periods were associated with increased susceptibility to autism risk.

Researchers suspect that the risk factors for autism start early in life, even prenatally, but measuring in utero exposures is technically very challenging. We used a newly developed technique that uses lasers to map growth rings in baby teeth (like growth rings in trees) to reconstruct the history of toxic metal and essential nutrient uptake. We applied this technology in samples collected from twins, including twins who were discordant for autism. This allowed us to have some control over genetic factors.

We found that twins with autism had higher levels of lead in their teeth compared to their unaffected twin siblings. They also had lower levels of zinc and manganese. The lower uptake of zinc was restricted to approximately 10 weeks before birth to a few weeks after birth, indicating that as a critical developmental period.

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Gene Dosage at 22q11.2 Helps Determine Schizophrenia vs Autism Brain Differences

MedicalResearch.com Interview with:

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

Dr. Bearden

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.

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Metformin Reverses Some Autism Symptoms In Animal Model

MedicalResearch.com Interview with:
Ilse Gantois, PhD

Research Associate
Dr. Nahum Sonenberg’s laboratory
Department of Biochemistry
McGill University

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Fragile X syndrome (FXS) is a neurodevelopmental disorder characterized by cognitive impairment and affects 1 in 4000 males and 1 in 6000 females. About 60% of persons with Fragile X also have autism spectrum disorder. FXS is caused by absence of Fragile X protein (FMRP), which results in hyperactivation of ERK (extracellular signal-regulated kinase) and mTORC1 (mechanistic target of rapamycin complex 1) signaling. We show that treatment with metformin, the most widely used FDA-approved antidiabetic drug, suppresses translation by inhibiting the ERK pathway, and alleviates a variety of behavioural deficits, including impaired social interaction and excessive grooming. In addition, metformin also reversed defects in dendritic spine morphogenesis and synaptic transmission.
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