Screening

Newly Published Genetics/Brain Tissue Study Will Help Refine the Search for Specific Early Genetic Markers of Risk of Autism in Babies and Toddlers

Source: 
PLoS Genetics
Date Published: 
March 22, 2012
Year Published: 
2012
Abstract: 

A new study of autism published today in PLoS Genetics has discovered abnormal gene activity and gene deletions in the same brain region that also has a 67% overabundance of brain cells. This region – the prefrontal cortex—is involved in social, emotional, communication and language skills. The finding brings new understanding of what early genetic abnormalities lead to excess brain cells and to the abnormal brain wiring that cause core symptoms in autism. Importantly, the study also shows that gene activity abnormalities in autism change across the lifespan.

By Dr. Eric Courchesne

A new study of autism published today in PLoS Genetics (Age Dependent Brain Gene Expression and Copy Number Anomalies in Autism Suggest Distinct Pathological Processes at Young Versus Mature Ages) has discovered abnormal gene activity and gene deletions in the same brain region that also has a 67% overabundance of brain cells.  This region – the prefrontal cortex—is involved in social, emotional, communication and language skills. The finding brings new understanding of what early genetic abnormalities lead to excess brain cells and to the abnormal brain wiring that cause core symptoms in autism. Importantly, the study also shows that gene activity abnormalities in autism change across the lifespan.

The research is one of the first to focus on gene activity inside the young autistic brain, and is the first to examine how gene expression activity changes across the lifespan in autism.  It is also one of the largest postmortem studies of autism to date. This close-up look inside the brain uncovered the presence of abnormal levels of activity in genes (“gene expression”) and gene defects (deletions of portions of DNA sequences) that control the number of brain cells and their growth and pattern of organization in the developing prefrontal cortex. The abnormal gene activity occurred in several networks that are important during prenatal brain development (cell cycle, neurogenesis, DNA damage detection and response, apoptosis and survival networks). This seems to rule out a number of current speculations about postnatal causes of autism and, combined with the new evidence of a 67% excess of prefrontal brain cells, points instead to prenatal causal events in a majority of cases.

The study’s direct examination of both mRNA and DNA from the same frontal cortex region in each individual is also a unique approach to discovering the genetics of abnormal brain development in autism.  The combined mRNA and DNA results indicate that a large and heterogeneous array of gene and gene expression defects disrupt prenatal processes that are critical to early prefrontal cortex formation. “Although DNA defects vary from autistic case to case, the diverse genetic deletions seem to underlie a relatively common biological theme, hitting a shared set of gene pathways that impact cell cycle, DNA damage detection and repair, migration, neural patterning and cell differentiation,” according to the study.  Importantly, the set of functional gene pathways identified by the study’s direct analyses of autistic brain tissue are consistent with those identified by previous studies that analyzed copy number variations in living autistic patients.

A second major discovery in this study is that the pattern of abnormal gene activity changes across the lifespan in autism. Thus, in adults with autism, the study found abnormal activity in genes involved in remodeling, repair, immune response and signaling. This raises opportunities for new research directions that ask whether and how such later alterations in genetic activity impact brain structure and function.  A hope is that perhaps this later, second stage of unusual genetic activity we detected in adults with autism has something to do with enhancing adaptive connections and pruning back earlier maladaptive connections.  Further research needs to better understand the impact of those later changes in genetic activity.

Findings in the new study will help refine the search for specific early genetic markers of risk of autism in babies and toddlers.  Next steps include identifying what causes the altered genetic activity at early stages of development, when nerve cells in prefrontal cortex arise and the first steps in creating brain circuitry are being taken.  Knowledge of these specific patterns of abnormal gene activity may also give rise to future studies that search for medical interventions that target abnormal gene activity in an age-specific fashion.

New Autism Research Reveals Brain Differences at 6 Months in Infants Who Develop Autism

Source: 
Center for Autism Research at The Children's Hospital of Philadelphia (CHOP)
Date Published: 
February 17, 2012
Abstract: 

A new study from the Infant Brain Imaging Network, which includes researchers at the Center for Autism Research at The Children's Hospital of Philadelphia (CHOP), found significant differences in brain development starting at age 6 months in high-risk infants who later develop autism, compared to high-risk infants who did not develop autism.

In the Brain, Signs of Autism as Early as 6 Months Old

Source: 
Science Daily
Date Published: 
January 30, 2012
Abstract: 

Measuring brain activity in infants as young as six months may help to predict the future development of autism symptoms.

Automated Imaging Inroduced To Greatly Speed Whole-Brain Mapping Efforts

Source: 
Medical News Today
Date Published: 
January 17, 2012
Abstract: 

A new technology developed by neuroscientists at Cold Spring Harbor Laboratory (CSHL) transforms the way highly detailed anatomical images can be made of whole brains.

Movement during brain scans may lead to spurious patterns

Source: 
SFARI
Date Published: 
January 16, 2011
Abstract: 

Head movements taint the results of many brain imaging studies, particularly those analyzing children or individuals with autism. That’s the sobering message from two independent studies published over the past few months in NeuroImage.

67% More Prefrontal Brain Neurons In Children With Autism

Source: 
Medical News Today
Date Published: 
November 8, 2011
Abstract: 

A small study found that male children with autism had larger brain weights and 67% more prefrontal brain neurons than children without autism.

Association Between Behavioral Features and Gastrointestinal Problems Among Children with Autism Spectrum Disorder

Source: 
Journal of Autism and Developmental Disorders - Maenner, M.J. et al.
Date Published: 
October 25, 2011
Year Published: 
2011

Recent reports suggest certain behaviors among children with autism spectrum disorders (ASD) may indicate underlying gastro-intestinal (GI) problems, and that the presence of these behaviors may help alert primary care providers to the need to evaluate a child with ASD for GI problems. The purpose of this population-based study of 487 children with ASD, including 35 (7.2%) with a medically documented history of GI problems, was to compare behavioral features of children with and without a history of GI problems. Unusual sleeping or eating habits and oppositional behavior were significantly associated with GI problems. These behaviors, however, were frequent in both children with and without GI problems, suggesting they may have limited utility in a screening capacity for GI problems.

University of Missouri researchers have found distinct differences between the facial characteristics of children with autism compared to those of typically developing children.

Source: 
Medical News Today
Date Published: 
October 22, 2011
Abstract: 

The face and brain develop in coordination, with each influencing the other, beginning in the embryo and continuing through adolescence. Now, University of Missouri researchers have found distinct differences between the facial characteristics of children with autism compared to those of typically developing children...

Having A Child With Autism Linked To Genetic Variant And Autoantibodies: Finding May Lead To Screening Test

Source: 
Medical News Today
Date Published: 
October 20, 2011
Abstract: 

A study by researchers at UC Davis has found that pregnant women with a particular gene variation are more likely to produce autoantibodies to the brains of their developing fetuses and that the children of these mothers are at greater risk of later being diagnosed with autism.

Diagnosing Autism At A Younger Age Could Lead To Earlier Interventions

Source: 
Medical News Today
Date Published: 
October 16, 2011
Abstract: 

Autism is normally diagnosed between the ages of 2 and 3, but new research is finding symptoms of autism spectrum disorders in babies as young as 12 months.