Genetics

Researchers Reveal First Autism Candidate Gene That Demonstrates Sensitivity to Sex Hormones

Source: 
Science Daily
Date Published: 
February 17, 2011
Abstract: 

George Washington University researcher, Dr. Valerie Hu, Professor of Biochemistry and Molecular Biology, and her team at the School of Medicine and Health Sciences, have found that male and female sex hormones regulate expression of an important gene in neuronal cell culture through a mechanism that could explain not only higher levels of testosterone observed in some individuals with autism, but also why males have a higher incidence of autism than females.

Surprising View of Brain Formation: Discovery of a New Mechanism May Have Implications for a Host of Diseases

Source: 
Science Daily
Date Published: 
February 10, 2011
Abstract: 

A study from The Scripps Research Institute has unveiled a surprising mechanism that controls brain formation. In the new study, Mueller and colleagues focused on a protein called reelin. They found reelin is a key player in the migration of new nerve cells to the neocortex, the part of the brain responsible for higher-order functions, such as language and movement. The findings have implications for understanding a host of diseases, including some forms of mental retardation, epilepsy, schizophrenia, and autism.

Autism and Increased Paternal Age Related Changes in Global Levels of Gene Expression Regulation

Source: 
PloS One, Alter et al.
Date Published: 
February 2011
Year Published: 
2011

This study, performed by researchers at the University of Pennsylvania, analyzed the level of gene expression in children with autism, compared with a control group. The researchers hypothesized that the variability in the pattern of the overall of gene expression levels would be associated with variability in hippocampal-dependent behaviors, which include short-term memory and spatial navigation. Additionally, the group tested whether increased paternal age was associated with variance of gene expression. A decrease in the variability of gene expression levels was associated with the diagnosis of autism and increased paternal age. The research team believes this change to be caused by the down-regulation of gene expression pathways involved in protein synthesis regulation in the blood of children with autism and children with older fathers. Thus, the researchers concluded that alterations at the gene level of gene expression regulation are related to autism and increased paternal age.

Autism Risk Linked To Space Between First And Second Pregnancy

Source: 
Medical News Today
Date Published: 
January 10, 2011
Abstract: 

A second child is three times more likely to be diagnosed with autism if they are born within twelve months of their siblings, compared to those born three or more years apart, researchers from the Lazarsfeld Center for the Social Sciences at Columbia University, New York revealed in the journal Pediatrics. The investigators gathered information on 660,000 second children born in California between 1992 to 2002.

A Set Of Brain Proteins Is Found To Play A Role In Over 100 Brain Diseases And Provides A New Insight Into Evolution Of Behavior

Source: 
Medical News Today
Date Published: 
December 21, 2010
Abstract: 

In research just published, scientists have studied human brain samples to isolate a set of proteins that accounts for over 130 brain diseases. The paper also shows an intriguing link between diseases and the evolution of the human brain.

Researchers Develop Mouse Model To Help Find How A Gene Mutation Leads To Autism

Source: 
Medical News Today
Date Published: 
December 20, 2010
Abstract: 

Researchers from Mount Sinai School of Medicine have found that when one copy of the SHANK3 gene in mice is missing, nerve cells do not effectively communicate and do not show cellular properties associated with normal learning. This discovery may explain how mutations affecting SHANK3 may lead to autism spectrum disorders (ASDs). The research is currently published in Molecular Autism.

Altered Functional Connectivity in Frontal Lobe Circuits Is Associated with Variation in the Autism Risk Gene CNTNAP2

Source: 
Pediatrics, Scott-Van Zeeland et al
Date Published: 
December 2010
Year Published: 
2010

People with a common variant of the CNTNAP2 gene, a gene associated with a heightened risk of autism, ADD/ADHD and other language difficulties, have a "disconnect" between their frontal lobe and other areas of the brain important for language, according to this fMRI study. The disconnect may help explain some of the language and communication difficulties that are characteristic of autism. About one-third of all people carry the variant of the CNTNAP2 gene.

Regardless of whether the test subjects had autism or not, children with the CNTNAP2 "risk" gene showed more activity in the frontal lobe of the brain during a "language learning" task than those without the 'risk' gene.

Changes in Prefrontal Axons May Disrupt the Network in Autism

Source: 
Journal of Neuroscience, Zikopoulos and Barbas
Date Published: 
December 2010
Year Published: 
2010

A post-mortem investigation measuring features of the different axons traveling beneath the cortical surface. The crux of the study is whether in autism there are changes in axons, "which are the conduit for neural communication." In comparison to control samples, autism brain tissue had fewer large axons connecting regions of the prefrontal cortex to the other areas of cortex.  Added to this connection imbalance is a thinner coat of axon insulation, called myelin. These findings may help explain why individuals with autism do not adequately shift attention, engage in repetitive behavior, and avoid social interactions.

Children With Autism Have Mitochondrial Dysfunction, Study Finds

Source: 
Science Daily
Date Published: 
November 30, 2010
Abstract: 

Children with autism are far more likely to have deficits in their ability to produce cellular energy than are typically developing children, a new study by researchers at UC Davis has found. The study, published in the Journal of the American Medical Association (JAMA), found that cumulative damage and oxidative stress in mitochondria, the cell's energy producer, could influence both the onset and severity of autism, suggesting a strong link between autism and mitochondrial defects.

Brain Scans Detect Autism's Signature

Source: 
Science Daily
Date Published: 
November 16, 2010
Abstract: 

An autism study by Yale School of Medicine researchers using functional magnetic resonance imaging (fMRI) has identified a pattern of brain activity that may characterize the genetic vulnerability to developing autism spectrum disorder (ASD).

The team identified three distinct "neural signatures": trait markers -- brain regions with reduced activity in children with ASD and their unaffected siblings; state markers -- brain areas with reduced activity found only in children with autism; and compensatory activity -- enhanced activity seen only in unaffected siblings. The enhanced brain activity may reflect a developmental process by which these children overcome a genetic predisposition to develop ASD.