UCLA scientists have discovered a variant of a gene called CACNA1G that may increase a child's risk of developing autism, particularly in boys. The journal Molecular Psychiatry publishes the findings in its May 19 advance online edition.
Classic autism strikes boys four times more often than girls. When including the entire spectrum of autism disorders, such as the milder Asperger syndrome, boys are diagnosed 10 times more often than girls.
"This is a strong finding," said Dr. Stanley Nelson, professor of human genetics at the David Geffen School of Medicine at UCLA. "No one has scrutinized the role that CACNA1G plays in autism.
"We found that a common form of the gene occurs more frequently in the DNA of families that have two or more sons affected by autism, but no affected daughters," he explained. "Our study may explain why boys are more susceptible to the disorder than girls."
Nelson and his colleagues zeroed in on a region of Chromosome 17 that previous studies have tied to autism. The research team scoured the DNA of 1,046 members of families with at least two sons affected by autism for common gene variants.
A variant is a gene that has undergone subtle changes from the normal DNA yet is shared by a significant portion of the population.
The researchers used tools of the Human Genome Project to scan thousands of variants across all genes in the suspicious region of the chromosome and to pluck out the most common forms.
"We wanted to identify what was happening in this region of Chromosome 17 that boosts autism risk," said Nelson. "When the same genetic markers kept cropping up in a single region of the DNA, we knew we had uncovered a big clue."
The researchers traced the genetic markers to CACNA1G, which helps move calcium between the cells. They discovered that the gene has a common variant that appears in the DNA of nearly 40 percent of the population.
"This alternate form of CACNA1G consistently increased the correlation to autism spectrum disorder, suggesting that inheriting the gene may heighten a child's risk of developing autism," observed Nelson.
How the gene contributes to higher autism risk remains unclear, but Nelson emphasized that it cannot be considered a risk factor on its own.
"This variant is a single piece of the puzzle," he said. "We need a larger sample size to identify all of the genes involved in autism and to solve the whole puzzle of this disease."
The UCLA team's next step will be to sequence the gene in people who possess the altered variant in order to identify the exact change that increases autism risk. These subtle variations offer potential markers for the real mutation causing greater susceptibility to the disease.
Nelson's coauthors included Samuel Strom, Jennifer Stone, John ten Bosch, Barry Merriman, Rita Cantor and Daniel Geschwind, all of UCLA. The study was funded by the National Institute of Mental Health and Cure Autism Now, which has since merged with Autism Speaks.
The DNA samples and clinical data were provided by families who donated blood to the Los Angeles–based Autism Genetic Resource Exchange (AGRE), a program created and funded by Cure Autism Now.
"When parents like me first formed AGRE, this was our dream, that talented scientists would use our gene bank to collaborate and bring us closer to understanding autism," said Jon Shestack, co-founder of Cure Autism Now and a board member of Autism Speaks. "AGRE has played an important role in almost every major autism genetics paper in the past five years."
Autism is a complex brain disorder that strikes in early childhood. The condition disrupts a child's ability to communicate and develop social relationships and is often accompanied by acute behavioral challenges. The Centers for Disease Control and Prevention report that one in 150 American children is diagnosed with an autism spectrum disorder. The diagnosis of autism has expanded tenfold in the last decade.
Elaine Schmidt | EurekAlert!
Switch-in-a-cell electrifies life
18.12.2018 | Rice University
Plant biologists identify mechanism behind transition from insect to wind pollination
18.12.2018 | University of Toronto
Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.
Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...
The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.
Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...
What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
18.12.2018 | Materials Sciences
18.12.2018 | Physics and Astronomy
18.12.2018 | Physics and Astronomy