Study explains functional links between autism and genes

June 21, 2012

A pioneering report of genome-wide gene expression in autism spectrum disorders (ASDs) finds genetic changes that help explain why one person has an ASD and another does not. The study, published by Cell Press on June 21 in The American Journal of Human Genetics, pinpoints ASD risk factors by comparing changes in gene expression with DNA mutation data in the same individuals. This innovative approach is likely to pave the way for future personalized medicine, not just for ASD but also for any disease with a genetic component.

ASDs are a heterogeneous group of developmental conditions characterized by social deficits, difficulty communicating, and repetitive behaviors. ASDs are thought to be highly heritable, meaning that they run in families. However, the genetics of autism are complex.

Researchers have found rare changes in the number of copies of defined genetic regions that associate with ASD. Although there are some hot-spot regions containing these alterations, very few genetic changes are exactly alike. Similarly, no two autistic people share the exact same symptoms. To discover how these genetic changes might affect and, thus, the presentation of the disorder, Rui Luo, a graduate student in the Geschwind lab at UCLA, studied 244 families in which one child (the proband) was affected with an ASD and one was not.

In addition to identifying several potential new regions where copy-number variants () are associated with ASDs, Geschwind's team found genes within these regions to be significantly misregulated in ASD children compared with their unaffected siblings. "Strikingly, we observed a higher incidence of haploinsufficient genes in the rare CNVs in probands than in those of siblings, strongly indicating a functional impact of these CNVs on expression," says Geschwind. Haploinsuffiency occurs when only one copy of a gene is functional; the result is that the body cannot produce a normal amount of protein. The researchers also found a significant enrichment of misexpressed genes in neural-related pathways in ASD children. Previous research has found that these pathways include other genetic variants associated with autism, which Geschwind explains further legitimizes the present findings.

Explore further: Further support for a role of synaptic proteins in autism spectrum disorders

More information: Luo et al.: "Genome-wide Transcriptome Profiling Reveals the Functional Impact of Rare De Novo and Recurrent CNVs in Autism Spectrum Disorders." DOI 10.1016/j.ajhg.2012.05.011

Related Stories

Further support for a role of synaptic proteins in autism spectrum disorders

February 9, 2012
A new study combines genetic and neurobiological approaches to confirm that synaptic mutations increase the risk of autism spectrum disorders (ASDs). It also highlights a role for modifier genes in these disorders. Published ...

18 novel subtype-dependent genetic variants for autism spectrum disorders revealed

April 27, 2011
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 ...

Study shows delays in siblings of children with autism spectrum disorders

May 16, 2012
A new University of Miami (UM) study shows that one in three children who have an older sibling with an Autism Related Disorder (ASD) fall into a group characterized by higher levels of autism-related behaviors or lower levels ...

Study finds new ADHD genes, links susceptibility with autism and other neuropsychiatric conditions

August 10, 2011
New research led by The Hospital for Sick Children (SickKids) and the University of Toronto has identified more genes in attention deficit hyperactivity disorder (ADHD) and shows that there is an overlap between some of these ...

Recommended for you

Genome editing reveals role of gene important for human embryo development

September 20, 2017
Researchers have used genome editing technology to reveal the role of a key gene in human embryos in the first few days of development. This is the first time that genome editing has been used to study gene function in human ...

A piece of the puzzle: Eight autism-related mutations in one gene

September 19, 2017
Scientists have identified a hotspot for autism-related mutations in a single gene.

Scientists identify key regulator of male fertility

September 19, 2017
When it comes to male reproductive fertility, timing is everything. Now scientists are finding new details on how disruption of this timing may contribute to male infertility or congenital illness.

New assay leads to step toward gene therapy for deaf patients

September 18, 2017
Scientists at Oregon State University have taken an important step toward gene therapy for deaf patients by developing a way to better study a large protein essential for hearing and finding a truncated version of it.

Genomic recycling: Ancestral genes take on new roles

September 18, 2017
One often hears about the multitude of genes we have in common with chimps, birds or other living creatures, but such comparisons are sometimes misleading. The shared percentage usually refers only to genes that encode instructions ...

Biologists identify gene involved in kidney-related birth defects

September 18, 2017
A team led by University of Iowa researchers has identified a gene linked to rare, often fatal kidney-related birth defects.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.