Copy Number Variations

Functional impact of global rare copy number variation in autism spectrum disorders

Source: 
Nature
Date Published: 
June 7, 2010
Abstract: 

This study analysed the genome-wide characteristics of rare (<1% frequency) copy number variation in ASD using dense genotyping arrays. When comparing 996 ASD individuals of European ancestry to 1,287 matched controls, cases were found to carry a higher global burden of rare, genic copy number variants (CNVs), especially so for loci previously implicated in either ASD and/or intellectual disability. Among the CNVs there were numerous de novo and inherited events, sometimes in combination in a given family, implicating many novel ASD genes such as SHANK2, SYNGAP1, DLGAP2 and the X-linked DDX53–PTCHD1 locus. We also discovered an enrichment of CNVs disrupting functional gene sets involved in cellular proliferation, projection and motility, and GTPase/Ras signaling. Our results reveal many new genetic and functional targets in ASD that may lead to final connected pathways.

Mutations in the SHANK2 Synaptic Scaffolding Gene in Autism Spectrum

Source: 
Nature Genetics, Berkel et al
Date Published: 
June 2010
Year Published: 
2010

Using microarrays, the department of molecular human genetics in Heidelberg, Germany identified de novo copy number variations in the SHANK2 synaptic scaffolding gene in two unrelated individuals with autism-spectrum disorder (ASD) and mental retardation. DNA sequencing of SHANK2 in 396 individuals with ASD, 184 individuals with mental retardation and 659 unaffected individuals (controls) revealed additional variants that were specific to ASD and mental retardation cases, including a de novo nonsense mutation and seven rare inherited changes. Their findings further link common genes between ASD and intellectual disability.

IntegraGen Announces Publication of Four Genetic Variants in Autism

Source: 
Medical News Today
Date Published: 
May 14, 2010
Abstract: 

IntegraGen SA, a French biotechnology company dedicated to gene discovery, announced today the publication of the results of a collaborative study reporting the use of a combined analysis of multiple genetic variants in a genetic score to help identify individuals at high risk of developing autism.

Schizophrenia Shares Genetic Links with Autism, Genome Study Shows

Source: 
Scientific American
Date Published: 
May 10, 2010
Abstract: 

Schizophrenia involves some of the same genetic variations as autism and attention deficit disorders, a new whole-genome study has confirmed. In an effort to assess some of the common genetic variations that might underpin this fairly common but thorny mental illness, researchers sequenced DNA from 1,735 adults with schizophrenia and 3,485 healthy adults. Across the patients that had the disease, the researchers found many frequent variations related to copying or deleting genes, known as copy-number variations.

Better Genetic Test for Autism?

Source: 
Science Daily
Date Published: 
March 15, 2010
Abstract: 

A large study from Children's Hospital Boston and the Boston-based Autism Consortium finds that a genetic test that samples the entire genome, known as chromosomal microarray analysis, has about three times the detection rate for genetic changes related to autism spectrum disorders (ASDs) than standard tests.

The Top 10 Everything of 2009.# 7: New Research on Autism

Source: 
Time Magazine
Date Published: 
December 8, 2009
Abstract: 

TIME recognized New Research on Autism as #7 of its Top 10 Medical Breakthroughs of 2009.

Autism-Risk Gene Rewires the Brain in a Way That Disrupts Learning and Language Acquisition

Source: 
Medical News Today
Date Published: 
November 3, 2010
Abstract: 

Researchers at UCLA have discovered how an autism-risk gene rewires the brain, which could pave the way for treatments aimed at rebalancing brain circuits during early development. Dr. Geschwind and team examined the variations in brain function and connectivity resulting from two forms of the CNTNAP2 gene - one form of the gene increases the risk of autism. The researchers suspected that CNTNAP2 might have an important impact on brain activity. They used fMRI (functional magnetic resonance imaging) to scan 32 children's brains while they were performing tasks related to learning. Only 16 of them had autism.

The imaging results confirmed their suspicions. All the children with the autism-risk gene showed a disjointed brain, regardless of their diagnosis. Their frontal lobe was over-connected to itself, while connection to the rest of the brain was poor, especially with the back of the brain. There was also a difference between how the left and right sides of the brain connected with each other, depending on which CNTNAP2 version the child carried.

The authors believe their findings could help identify autism risk earlier, and eventually lead to interventions that could enhance connections between the frontal lobe and the left side of the brain.

Genome Wide Study of Autism Published in Nature

Source: 
EurekAlert
Date Published: 
October 7, 2009
Abstract: 

In one of the first studies of its kind, an international team of researchers has uncovered a single-letter change in the genetic code that is associated with autism. The finding, published in the October 8 issue of the journal Nature, implicates a neuronal gene not previously tied to the disorder and more broadly, underscores a role for common DNA variation. In addition, the new research highlights two other regions of the genome, which are likely to contain rare genetic differences that may also influence autism risk.

Genome-Wide Analyses of Exonic Copy Number Variants in a Family-Based Study Point to Novel Autism Susceptibility Genes

Source: 
PLOS Genetics, Bucan M, Abrahams BS, Wang K, Glessner JT, Herman EI, et al.
Date Published: 
June 2009
Year Published: 
2009

The study identified 27 different genetic regions where rare copy number variations - missing or extra copies of DNA segments - were found in the genes of children with autism spectrum disorders, but not in the healthy controls. The researchers, including geneticists from the University of Pennsylvania School of Medicine and The Children's Hospital of Philadelphia (CHOP) compared genetic samples of 3,832 individuals from 912 families with multiple autistic children against genetic samples of 1,070 disease-free children. Besides the identification of 27 regions harboring rare variants in children with ASDs, the study also uncovered two novel genes where variations were found, BZRAP1 and MDGA2 - thought to be important in synaptic function and neurological development, respectively. Interestingly, key variants on these genes were passed down in some, but not all, of the affected individuals in families.

Newly Found Genetic Variation Linked to Autism

Source: 
Nature
Date Published: 
April 2009
Year Published: 
2009

A newly identified genetic variant could account for up to 15 percent of autism cases, say researchers who studied genes that are important in connecting brain cells.  Researchers say the variant is carried by about 65 per cent of people with autism.