Genomics

Gene Variants in Autism Linked to Brain Development

Source: 
Science Daily
Date Published: 
March 7, 2011
Abstract: 

New 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.

Gene Variants in Autism Linked to Brain Development

Source: 
Journal of Molecular Psychiatry, Gai et al.
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.

New Autism Susceptibilty Genes Identified

Source: 
Medical News Today
Date Published: 
June 10, 2010
Abstract: 

Mount Sinai researchers and the Autism Genome Project Consortium (AGP) announced that they have identified new autism susceptibility genes that may lead to the development of new treatment approaches. These genes, which include SHANK2, SYNGAP1, DLGAP2 and the X-linked DDX53-PTCHD1 locus, primarily belong to synapse-related pathways, while others are involved in cellular proliferation, projection and motility, and intracellular signaling

New Genetic Risk Factor for Both Autism and Schizophrenia

Source: 
Science Daily
Date Published: 
November 4, 2010
Abstract: 

Researchers have uncovered a prominent genetic risk factor for autism spectrum disorders and schizophrenia is a small genomic deletion. Remarkably, they found the same deletion on chromosome 17 in 24 separate patients. This CNV was absent in 52,448 controls, making the finding statistically significant. Someone with this deletion is 13.58 times more likely to develop ASD or schizophrenia than is someone lacking this CNV. This gene mutation is also known to cause kidney disease (renal cysts and diabetes syndrome, RCAD).

Gene Scan Finds Link Across Array of Childhood Brain Disorder

Source: 
EurekAlert
Date Published: 
August 22, 2010
Abstract: 

Mutations in a single gene can cause several types of developmental brain abnormalities that experts have traditionally considered different disorders. With support from the National Institutes of Health, researchers found those mutations through whole exome sequencing – a new gene scanning technology that cuts the cost and time of searching for rare mutations. Whole exome sequencing can be applied to dozens of other rare genetic disorders where the culprit genes have so far evaded discovery. Such information can help couples assess the risk of passing on genetic disorders to their children. It can also offer insights into disease mechanisms and treatments.

Developmental Problems, Some Exist in the Genes

Source: 
Medical News Today
Date Published: 
August 18, 2010
Abstract: 

DNA for each individual contains variants that are more or less common in the overall population.

Some gene variations are actually genetic deletions, where sections of DNA 'code' are missing entirely. These variants are likely to have important effects on gene function and, therefore, likely to contribute to diseases associated with that gene. But what happens when multiple genes are disrupted in a single family?

Disturbances in Certain Genes Play a Role in Autism

Source: 
Medical News Today
Date Published: 
August 17, 2010
Abstract: 

Together with colleagues from an international research group, autism researcher Christopher Gillberg of the University of Gothenburg, Sweden, has found in a new study that autism can be partially explained by abnormalities in certain genes. The group's results could, in the long run, pave the way for more appropriate treatments for autism.

In the article the group reveals that a survey of 1,000 individuals with autism and 1,300 without showed that Copy Number Variants (CNVs) sub-microscopic abnormalities in the chromosomes are heavily over-represented in autistic people.

Functional Impact of Global Rare Copy Number Variation in Autism Spectrum Disorders

Source: 
Nature, Pinto et al
Date Published: 
July 2010
Year Published: 
2010

A genome-wide analysis reveals that people with ASDs carry a higher load of rare copy-number variants — segments of DNA for which the copy number differs between individual genomes — which are either inherited or arise de novo. The results implicate several novel genes as ASD candidates and point to the importance of cellular proliferation, projection and motility as well as specific signalling pathways in this disorder.

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.

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.