Biomarkers

Evidence found for the genetic basis of autism: Models of autism show that gene copy number controls

Submitted by Anonymous on October 5, 2011 - 11:40
Source: 
Science Daily
Link: 
http://www.sciencedaily.com/releases/2011/10/111003151819.htm
Date Published: 
October 5, 2011
Abstract: 

Scientists at Cold Spring Harbor Laboratory (CSHL) have discovered that one of the most common genetic alterations in autism -- deletion of a 27-gene cluster on chromosome 16 -- causes autism-like features. By generating mouse models of autism using a technique known as chromosome engineering, CSHL Professor Alea Mills and colleagues provide the first functional evidence that inheriting fewer copies of these genes leads to features resembling those used to diagnose children with autism.

Animal Model Research Could Lead To The Development Of Diagnostic Tests For Autism Based On Biomarkers

Submitted by Anonymous on September 13, 2011 - 23:00
Source: 
Medical News Today
Link: 
http://www.medicalnewstoday.com/releases/234318.php
Date Published: 
September 14, 2011
Abstract: 

The first transgenic mouse model of a rare and severe type of autism called Timothy Syndrome is improving the scientific understanding of autism spectrum disorder in general and may help researchers design more targeted interventions and treatments.

Multivariate Searchlight Classification of Structural Magnetic Resonance Imaging in Children and Adolescents with Autism

Submitted by Anonymous on September 4, 2011 - 23:00
Source: 
Biological Psychiatry
Link: 
http://www.biologicalpsychiatryjournal.com/article/S0006-3223(11)00727-X/abstract
Date Published: 
September 5, 2011
Abstract: 

Multiple brain regions, including those belonging to the default mode network, exhibit aberrant structural organization in children with autism. Brain-based biomarkers derived from structural magnetic resonance imaging data may contribute to identification of the neuroanatomical basis of symptom heterogeneity and to the development of targeted early interventions.

Distinct features of autistic brain revealed in novel Stanford/Packard analysis of MRI scans

Submitted by Anonymous on September 1, 2011 - 23:00
Source: 
Stanford University
Link: 
http://med.stanford.edu/ism/2011/september/menon.html
Date Published: 
September 2, 2011
Abstract: 

Researchers at the Stanford University School of Medicine and Lucile Packard Children's Hospital have used a novel method for analyzing brain-scan data to distinguish children with autism from typically developing children. Their discovery reveals that the gray matter in a network of brain regions known to affect social communication and self-related thoughts has a distinct organization in people with autism.

Attention deficit, autism share genetic risk factors

Submitted by Anonymous on August 22, 2011 - 13:36
Source: 
SFARI
Link: 
http://sfari.org/news-and-opinion/news/2011/attention-deficit-autism-share-genetic-risk-factors
Date Published: 
August 22, 2011
Abstract: 

People with autism and attention deficit hyperactivity disorder (ADHD) share some of the same underlying genetic risk factors, according to a study published this month in Science Translational Medicine. This is one of the first studies to find risk variants that are common to both disorders.
In searching for rare copy number variations (CNVs) — deletions and duplications in genetic material — in people with ADHD, the researchers found more than a dozen regions that include genes implicated in bipolar disorder, schizophrenia, intellectual disability and autism.

Researchers Reveal 18 Novel Subtype-Dependent Genetic Variants for Autism Spectrum Disorders and Identify Potential Genetic Markers for Diagnostic Screening

Submitted by Anonymous on April 28, 2011 - 04:43
Source: 
Science Daily
Link: 
http://www.sciencedaily.com/releases/2011/04/110427171517.htm
Date Published: 
April 28, 2011
Abstract: 

By dividing individuals with autism spectrum disorders (ASD) into four subtypes according to similarity of symptoms and reanalyzing existing genome-wide genetic data on these individuals vs. controls, researchers at the George Washington University School of Medicine and Health Sciences have identified 18 novel and highly significant genetic markers for ASD. In addition, ten of the variants were associated with more than one ASD subtype, providing partial replication of these genetic markers. This study thus identifies candidate genes for ASD and potential subtype-dependent genetic markers for diagnostic screening.

MIT Researchers Recreate Autism in Mice

Submitted by Anonymous on March 20, 2011 - 04:55
Source: 
Medical News Today
Link: 
http://www.medicalnewstoday.com/articles/219485.php
Date Published: 
March 20, 2011
Abstract: 

By mutating a single gene, researchers at MIT and Duke have produced mice with two of the most common traits of autism - compulsive, repetitive behavior and avoidance of social interaction. In this study, the researchers focused on one of the most common of those genes, known as shank3. Shank3 is found in synapses - the junctions between brain cells that allow them to communicate with each other. Feng, who joined MIT and the McGovern Institute last year, began studying shank3 a few years ago because he thought that synaptic proteins might contribute to autism and similar brain disorders, such as obsessive compulsive disorder.

Gene Variants in Autism Linked to Brain Development

Submitted by bcrawford on March 1, 2011 - 00:00
Source: 
Journal of Molecular Psychiatry, Gai et al.
Link: 
http://www.nature.com/mp/journal/vaop/ncurrent/full/mp201110a.html
Date Published: 
March 2011
Year Published: 
2011

This research on the genomics of autism confirms that the genetic roots of the disorder are highly complicated, but that common biological themes underlie this complexity. In the current study, researchers have implicated several new candidate genes and genomic variants as contributors to autism, and conclude that many more remain to be discovered. While the gene alterations are individually very rare, they mostly appear to disrupt genes that play important functional roles in brain development and nerve signaling. While an association between genomic variants in certain nervous system processes and autism has been hypothesized in the past, this research definitively links these biological functions to autism. 

"This large study is the first to demonstrate a statistically significant connection between genomic variants in autism and both synaptic function and neurotransmission," said senior author Peter S. White, Ph.D., a molecular geneticist and director of the Center for Biomedical Informatics at The Children's Hospital of Philadelphia. Synapses are the contact points at which nerve cells communicate with other nerve cells, while neurotransmitters are the chemical messengers carrying those signals.

"Prior genomic studies of autism have successfully identified several genes that appear to confer risk for autism, but each gene appears to contribute to only a small percentage of cases," said the lead author, Xiaowu Gai, Ph.D. "Our approach considered whether groups of genes with common biological functions collectively accounted for a greater percentage of autism risk."

-- via Science Daily http://www.sciencedaily.com/releases/2011/03/110301111243.htm.

Shank3 Mutant Mice Display Autistic-like Behaviors and Striatal Dysfunction

Submitted by bcrawford on March 1, 2011 - 00:00
Source: 
Nature, Peça et al.
Link: 
http://www.nature.com/nature/journal/v472/n7344/full/nature09965.html
Date Published: 
March 2011
Year Published: 
2011

Currently, the neurological basis of autism spectrum disorders (ASDs) is poorly understood. “Shank3 is a postsynaptic protein, whose disruption at the genetic level is thought to be responsible for the development of 22q13 deletion syndrome (Phelan-McDermid syndrome) and other non-syndromic ASDs”. In this study, mice with the Shank3 deletion were seen to exhibit “self-injurious repetitive grooming and deficits in social interaction.” Cellular, electrophysiological, and biochemical analyses revealed defects at striatal synapses and cortico-striatal circuits in Shank3 mutant mice. The study’s findings demonstrate that Shank3 plays a critical role in the development of neuronal connectivity. The study also established a causality between a disruption in the Shank3 gene and the beginning of autistic-like behaviors in mice.

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

Submitted by Anonymous on February 17, 2011 - 05:03
Source: 
Science Daily
Link: 
http://www.sciencedaily.com/releases/2011/02/110216185402.htm
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.