Skip to main content
The Globe and Mail
Support Quality Journalism.
The Globe and Mail
First Access to Latest
Investment News
Collection of curated
e-books and guides
Inform your decisions via
Globe Investor Tools
Just$1.99
per week
for first 24 weeks

Enjoy unlimited digital access
Enjoy Unlimited Digital Access
Get full access to globeandmail.com
Just $1.99 per week for the first 24 weeks
Just $1.99 per week for the first 24 weeks
var select={root:".js-sub-pencil",control:".js-sub-pencil-control",open:"o-sub-pencil--open",closed:"o-sub-pencil--closed"},dom={},allowExpand=!0;function pencilInit(o){var e=arguments.length>1&&void 0!==arguments[1]&&arguments[1];select.root=o,dom.root=document.querySelector(select.root),dom.root&&(dom.control=document.querySelector(select.control),dom.control.addEventListener("click",onToggleClicked),setPanelState(e),window.addEventListener("scroll",onWindowScroll),dom.root.removeAttribute("hidden"))}function isPanelOpen(){return dom.root.classList.contains(select.open)}function setPanelState(o){dom.root.classList[o?"add":"remove"](select.open),dom.root.classList[o?"remove":"add"](select.closed),dom.control.setAttribute("aria-expanded",o)}function onToggleClicked(){var l=!isPanelOpen();setPanelState(l)}function onWindowScroll(){window.requestAnimationFrame(function() {var l=isPanelOpen(),n=0===(document.body.scrollTop||document.documentElement.scrollTop);n||l||!allowExpand?n&&l&&(allowExpand=!0,setPanelState(!1)):(allowExpand=!1,setPanelState(!0))});}pencilInit(".js-sub-pencil",!1); // via darwin-bg var slideIndex = 0; carousel(); function carousel() { var i; var x = document.getElementsByClassName("subs_valueprop"); for (i = 0; i < x.length; i++) { x[i].style.display = "none"; } slideIndex++; if (slideIndex> x.length) { slideIndex = 1; } x[slideIndex - 1].style.display = "block"; setTimeout(carousel, 2500); } //

Stephen Scherer, director of the Centre for Applied Genomics, Hospital for Sick Children, is pictured in a handout photo. A Canadian-led international research team has identified several new genetic mutations that appear to be linked to autism spectrum disorder, using a method that looks at the entire DNA code of affected individuals.

Handout

Efforts to trace the hidden factors underlying autism have received a potent boost from a Canadian-led study that combed through the whole genomes of autistic individuals and their families.

The findings, which include variations in four genes not previously linked to autism, are expected to improve prospects for early detection of autism in children and help guide the search for effective treatments.

"For the first time, we can really look at inherited variants," said Stephen Scherer, director of the Centre for Applied Genomics at the Toronto Hospital for Sick Children.

Story continues below advertisement

Along with Dr. Scherer, more than three dozen authors were involved in the international study, published online on Thursday by the American Journal of Human Genetics. Participating institutions included Duke University, BGI-Shenzhen, a major sequencing centre in China, and the advocacy organization Autism Speaks.

The million-dollar pilot study is an initial step toward a larger international effort to decode the entire DNA sequences of 10,000 families who are coping with autism over the next five years, including about 1,000 in Canada.

Researchers have long known that genes must play a crucial role in many cases of autism spectrum disorder (ASD), a broad range of syndromes characterized by problems with communication and social development. While the overall incidence of ASD in the general population is just over 1 per cent, the odds that the sibling of an autistic child will also appear in the spectrum of syndromes jump to 18 per cent. Yet most autistic individuals do not carry any of the gene variants already linked to ASD, meaning that dozens, if not hundreds, of gene combinations that could trigger it remain unknown. Typically, only one in five individuals with ASD can be linked to a specific genetic risk factor.

For the study, the group sequenced the whole genomes of 32 Canadians with full blown autism as well as those of their parents and some other family members. They found specific genetic variants – changes in individual genes – linked to ASD in about half of the families. Some of the variants occurred spontaneously while others were inherited. In at least one case, researchers were able to determine that a sibling who was not previously thought to have ASD was in fact on the spectrum and carried a relevant gene.

One goal of the study is to help identify young children who are likely to have ASD. Currently, the average age for diagnosis of ASD in Canada is about four and a half. Earlier diagnosis and intervention have been shown to improve outcomes and help families prepare to care for their autistic children.

"If there's a family history or a suspicion, we can do a genome sequencing to prioritize kids and get them into programs much earlier," Dr. Scherer said. With information gleaned from whole genome sequencing, families found to have specific gene variants that are linked to ASD might also be fast-tracked for drug trials that target the effects of those anomalies.

The study is the largest to date to apply whole-genome sequencing to autism and "a nice proof of principle" that dramatic improvements in genetic technologies will translate into clinical benefits, said Jonathan Sebat, director of the Beyster Center for Molecular Genomics of Psychiatric Diseases at the University of California, San Diego, which published a smaller whole-genome study last December.

Story continues below advertisement

In recent years, "the genetics of autism has just been blown wide open," Dr. Sebat added, with DNA sequencing making it possible not only to link genes to the risk of developing ASD but illuminating the precise biological causes of autism, currently thought to involve a breakdown in the formation and maintenance of connections between brain cells.

"Whole-genome sequencing is really the direction where we anticipate the field going, not just for research but clinically in the upcoming years," said Eric Morrow, a geneticist and child psychiatrist at Brown University in Rhode Island, who called the new work "exciting."

Your Globe

Build your personal news feed

  1. Follow topics and authors relevant to your reading interests.
  2. Check your Following feed daily, and never miss an article. Access your Following feed from your account menu at the top right corner of every page.

Follow the author of this article:

View more suggestions in Following Read more about following topics and authors
Report an error Editorial code of conduct
Due to technical reasons, we have temporarily removed commenting from our articles. We hope to have this fixed soon. Thank you for your patience. If you are looking to give feedback on our new site, please send it along to feedback@globeandmail.com. If you want to write a letter to the editor, please forward to letters@globeandmail.com.

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff. Non-subscribers can read and sort comments but will not be able to engage with them in any way. Click here to subscribe.

If you would like to write a letter to the editor, please forward it to letters@globeandmail.com. Readers can also interact with The Globe on Facebook and Twitter .

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff. Non-subscribers can read and sort comments but will not be able to engage with them in any way. Click here to subscribe.

If you would like to write a letter to the editor, please forward it to letters@globeandmail.com. Readers can also interact with The Globe on Facebook and Twitter .

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff.

We aim to create a safe and valuable space for discussion and debate. That means:

  • Treat others as you wish to be treated
  • Criticize ideas, not people
  • Stay on topic
  • Avoid the use of toxic and offensive language
  • Flag bad behaviour

If you do not see your comment posted immediately, it is being reviewed by the moderation team and may appear shortly, generally within an hour.

We aim to have all comments reviewed in a timely manner.

Comments that violate our community guidelines will not be posted.

Read our community guidelines here

Discussion loading ...

To view this site properly, enable cookies in your browser. Read our privacy policy to learn more.
How to enable cookies