Autism researchers have long believed that there is more than one gene involved in autism, and that these genes are interacting with one another to create the spectrum associated with the disorder.

For the first time, scientists at MIT found that mice carrying mutations in two candidate genes for autism have more severe symptoms than those with only one mutation. The two genes studied were PTEN and serotonin transporter. In female mice, mutations in PTEN impaired sociability while those who also had mutations in the serotonin gene had worse symptoms.

"We found that two genetic risk factors for autism spectrum disorders (ASDs) act cooperatively in mice to influence brain size and social behavior, both of which are altered in ASDs," said Damon T. Page, a Picower Institute postdoctoral fellow and lead investigator of the study, which appeared in the February 10 issue of PNAS.

If this result translates to humans, the interaction of these genes could serve as biomarkers for certain subsets of individuals with ASD. It will also mean that drugs for the treatment of autism would need to target multiple genes.

Read details of the report at - Multiple Genes Implicated In Autism; Discovery Could Lead To Drugs Targeting Gene Interactions

b5 media’s very own Kristina Chew, PhD - the mastermind behind Autism Vox - is going to be on Good Morning America on abc tomorrow morning!

Both Kristina and Ari Ne’eman, the president of the Autistic Self-Advocacy Network (ASAN), were interviewed about autism, and the director for the National Institute of Mental Health (NIMH), Tom Insel, will be in the segment as well.

Be sure to watch Kristina, Ari Ne’eman, and Tom Insel on Good Morning America tomorrow. You may just learn a thing or to about autism and mental health from three really good sources!

Elaine Warburton  www.geneticsandhealth.com

Grace at Kids Health Notes and Kristina at Autism Vox have both written about the gene CNTNAP2 being unequivocally implicated in Type 1 Autism.

In her article CNTNAP2, an autism susceptibility gene which I highly recommend,  Kristina writes a personal account of her ongoing experience with her son Charlie’s autism and discusses the recent research findings.

Do read Grace’s article titled CNTNAP2 ‘unequivocally implicated’ in Type 1 autism which summarizes the three main pieces of research appearing in the American Journal of Genetics.

For the scientists:

Contactin Associated Protein-Like 2 is also known as CDFE; NRXN4; CASPR2; DKFZp781D1846. This gene encodes a member of the neurexin family which functions in the vertebrate nervous system as cell adhesion molecules and receptors. This protein, like other neurexin proteins, contains epidermal growth factor repeats and laminin G domains. In addition, it includes an F5/8 type C domain, discoidin/neuropilin- and fibrinogen-like domains, thrombospondin N-terminal-like domains and a putative PDZ binding site. This protein is localized at the juxtaparanodes of myelinated axons and associated with potassium channels. It may play a role in the local differentiation of the axon into distinct functional subdomains. This gene encompasses almost 1.5% of chromosome 7 and is one of the largest genes in the human genome. It may represent a positional candidate gene for the DFNB13 form of nonsyndromic deafness.

Genomic position - chromosome: 7; Location: 7q35-q36

Elaine Warburton

My colleague Kristina at Autism Vox has written a great article about the genetic basis of Autism.  Research has indicated that either a deletion or a duplication of a section of chromosome 16 seems to contribute strongly to susceptibility to autism.

I highly recommend you click on the following link to read more:

http://www.autismvox.com/like-father-like-son/

Elaine Warburton

Further to my article on Fragile X Syndrome the BBC health website has posted this article:

“Genetic engineering has been used to alleviate symptoms Fragile X in mice, which is a leading cause of inherited learning difficulties and autism. There is currently no treatment for Fragile X syndrome, also linked to epilepsy and abnormal body growth, but the new work raises hopes of progress.

A Massachusetts team were able to trigger big improvements in the mice by tweaking just one gene, FMRP. The researchers, from the Picower Institute for Learning and Memory at Massachusetts Institute of Technology, examined mice which lack the FMRP gene, and show many of the symptoms associated with fragile X.

They also created mice that not only lacked FMRP, but also had a 50% reduction in mGluR5. This second group of mice showed fewer symptoms of fragile X, fewer signs of abnormalities in the brain, and fewer signs of abnormal body growth. For example, loss of the FMRP gene produces overgrowth of connections between nerve cells called dendritic spines.   However, when coupled with a 50% reduction in mGluR5, spine density was completely normal. The ‘double mutant’ mice also showed substantial reduction in epileptic seizures.

Lead researcher Dr Mark Bear said: “These findings have major therapeutic implications for fragile X syndrome and autism.”

Fragile X syndrome is known to be caused by loss of the gene for “fragile X mental retardation protein” (FMRP), which is believed to act as a brake on protein synthesis in specific areas of brain circuitry. The authors’ idea was that loss of the “brake” would allow another protein that stimulates this process, called metabotropic glutamate receptor 5 (mGluR5), to function unchecked.

For further information on this research visit: www.cellpress.com

Elaine Warburton

Kristina at Autism Vox scooped me on the latest study (drat my need to sleep!) to come out showing that autism is most likely due to more than one gene. Dr. Gerard Schellenberg says there may be four to six major genes and another 20 to 30 genes having a minor role. This isn’t a big surprise because we know that complex diseases like autism, depression, heart disease, and cancer are the result of both genetic and environmental factors.

What I’ve repeatedly said here about genetics research on controversial diseases, disorders, or characteristics is that it is not about the elimination of “undesirable” people from the population. Genetic testing isn’t always about prenatal diagnosis and abortion. Certainly, there are some who believe in eugenics but the majority of scientists are looking for genetic information that enhances diagnosis and treatment.

Dr. Geraldine Dawson:

Once we discover these susceptibility genes, we can immediately screen infants to identify those at risk early in life. Early identification can lead to early intervention, which could have a much more dramatic effect.

Also, when a gene is discovered, you discover the underlying biology of autism at the molecular level. Once you understand the biology you can develop a prevention strategy including medical approaches. Genetic research is a good strategy for eventually designing effective medical treatments for autism.

Read more

Genetics and Health just gained two new sister blogs in the b5media Science and Health Channel: Autism Vox and Cancer Commentary.

Autism Vox is written by a previous Genetics and Health featured blogger, Dr. Kristina Chew. She writes with the grace of a classics professor and the perspective of a mother who has a child with autism. Autism Vox will advocate for the needs of people with autism and their caregivers.

Cancer Commentary is not your ordinary blog about cancer. Dr. Jane Chin, an expert in cancer biochemistry, writes about cancer therapies, healing, and society. It’s more than just the facts, it’s about life too. Readers interested in genetics may want to read Dr. Chin’s post on cancer classification.

Read more about these two blogs at the official b5media launch post.

NB: Don’t forget April is Autism Awareness Month.