New light on genetics of autism

September 14, 2012

The genetics of autism is complex and possibly influenced by mutations with very large effects. EU genomics research has found more candidate genes that increase susceptibility to the condition.

The EU 'Using European and international populations to identify susceptibility loci' (Autism Molgen) project has completed a comprehensive study of European patients with (ASDs). The study group consisted of around 100 multiplex families where two or more individuals are affected and more than 370 simplex families where one member of the family has an ASD.

The benefit of advanced genomic techniques was used to study the involvement of both previously identified associated genes as well as new candidate alleles. Molecular genetics techniques included linkage studies, association studies and mutation screening.

Using linkage studies to help refine the position of important loci and help identify possible new , logarithm of the odds (LOD) scores were applied to linkage data. A positive score indicating the presence of linkage was achieved for the long arm of chromosome 2, (2q), confirming the importance of this region in ASDs.

Two new candidate genes were identified among (SNPs) using the transmission disequilibrium test (TDT) to test presence of linkage between a marker and a trait. Additional association studies using a further 37 genes revealed a further 5 key genes susceptibility for further study.

Recent research has reported that may play a large role in predisposition to ASDs. A key example is in the case of neuroligins – alterations in genes encoding neuroligins are implicated in autism and other cognitive disorders. Neuroligins are involved in the healthy functioning of synapses. Rare variants with possible functional effects were identified. These included non-synonymous changes altering the position of an amino acid in a protein, stop codon mutations that shorten a protein and splice site mutations that can result in aberrant products. All types of mutation were found both in genes associated with ASD and in other plausible candidates.

Comprehensive genetic data amassed by Autism Molgen has positively identified new susceptibility alleles for ASDs. Future research can focus on functional studies for the genes involved. Given that the incidence of ASDs is reportedly rising by the decade, the project research can contribute to the elucidation of this highly complex condition.

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

Related Stories

Mutations in 3 genes linked to autism spectrum disorders

April 4, 2012

Mutations in three new genes have been linked to autism, according to new studies including one with investigators at Mount Sinai School of Medicine. All three studies include lead investigators of the Autism Sequencing Consortium ...

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 ...

Recommended for you

New autism genes are revealed in largest-ever study

September 29, 2015

In the largest, most comprehensive genomic analysis of autism spectrum disorder (ASD) conducted to date, an international research team led by UC San Francisco scientists has identified 65 genes that play a role in the disorder, ...

Probing the mysterious perceptual world of autism

October 23, 2015

The perceptual world of a person with autism spectrum disorder (ASD) is unique. Beginning in infancy, people who have ASD observe and interpret images and social cues differently than others. Caltech researchers now have ...


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.