Media Releases

New genetic findings expected to accelerate autism testing and development of treatments

June 11, 2010

TORONTO, ON — Cana­di­an and inter­na­tion­al sci­en­tists have uncov­ered key changes in DNA in indi­vid­u­als with autism. The Phase 2 results of the multi­na­tion­al Autism Genome Project Con­sor­tium pub­lished in the June 9 advance online edi­tion of Nature, sub­stan­ti­ate the impor­tance of genes as sus­cep­ti­bil­i­ty fac­tors in autism spec­trum dis­or­ders.

This study is the largest of its kind, involv­ing 1,500 fam­i­lies and more than 120 sci­en­tists and clin­i­cians from across North Amer­i­ca and Europe. The team was led by Dr. Stephen Scher­er, cor­re­spond­ing author of the study, Senior Sci­en­tist at The Hos­pi­tal for Sick Chil­dren (Sick­Kids), Direc­tor of The Cen­tre for Applied Genomics at Sick­Kids and the McLaugh­lin Cen­tre at the Uni­ver­si­ty of Toron­to and Dr. Peter Szat­mari, co-prin­ci­pal inves­ti­ga­tor, Direc­tor of the Offord Cen­tre for Child Stud­ies and Pro­fes­sor at McMas­ter Uni­ver­si­ty. Dr. Dalila Pin­to, Post­doc­tor­al Research Fel­low at Sick­Kids, was lead author.

Using microar­rays (or gene-chip tech­nol­o­gy) in the high­est-res­o­lu­tion test­ing to date, researchers inves­ti­gat­ed indi­vid­u­als with autism spec­trum dis­or­ders (ASDs). ASDs, diag­nosed in one in 110 chil­dren, are a group of neu­rode­vel­op­men­tal con­di­tions result­ing in chal­lenges con­nect­ed to com­mu­ni­ca­tion, social under­stand­ing and behav­iour.

The researchers report­ed that indi­vid­u­als with ASDs tend­ed to car­ry more inser­tions and dele­tions affect­ing their genes — called copy num­ber vari­ants (CNV) — than did peo­ple in the con­trol group. Some of these CNVs appeared to be inher­it­ed, while oth­ers are con­sid­ered new, because they are found only in off­spring with autism and not in the par­ents. Dozens of new “autism risk genes” were dis­cov­ered, includ­ing some that might be help­ful in ear­ly diag­no­sis.

“We now know sev­er­al of the genes involved in autism and for the first time, we are able to tie many of these genes into the same bio­log­i­cal path­ways involved in brain func­tion,” says Scher­er. “Know­ing these autism genes are linked, we can begin to devel­op ther­a­pies to tar­get the com­mon path­ways involved.”

Szat­mari adds, “This study will lead to a par­a­digm shift when it comes our under­stand­ing of the root caus­es of autism and indeed oth­er neu­rode­vel­op­men­tal dis­or­ders. Pre­vi­ous­ly it was believed that autis­tic indi­vid­u­als share com­mon genet­ic vari­a­tions in a few genes. This research points to the fact that genet­ic vari­a­tions are actu­al­ly rare, mean­ing indi­vid­u­als with autism are genet­i­cal­ly quite unique. But as we dis­cov­er more and more of these vari­ants, the num­ber of cas­es of ASD we can explain increas­es sub­stan­tial­ly. ”

Accord­ing to Pin­to, “Anoth­er sur­pris­ing dis­cov­ery was the sig­nif­i­cant over­lap between autism sus­cep­ti­bil­i­ty genes and those genes that were pre­vi­ous­ly thought to be impli­cat­ed in intel­lec­tu­al dis­abil­i­ty. This sug­gests that at least some genet­ic risk fac­tors are shared at the path­way lev­el by dif­fer­ent men­tal health dis­or­ders and devel­op­men­tal dis­abil­i­ties, pro­vid­ing insights into pos­si­ble com­mon path­o­gen­ic mech­a­nisms”.

The study found that for about 10 per cent of the fam­i­lies stud­ied, there are some genet­ic clues that may assist in the ear­ly diag­no­sis of autism or relat­ed com­pli­ca­tions. The Cana­di­an researchers say the next step a goal is to set up mech­a­nisms and process­es so that all fam­i­lies who are inter­est­ed can have access to this test­ing.

“Guid­ed by these mas­sive genom­ic data sets, we can start to see the for­est through the trees, offer­ing answers and hope for fam­i­lies with autism,” says Scher­er.

The Autism Genome Project con­sists of 120 sci­en­tists from more than 50 insti­tu­tions rep­re­sent­ing 12 coun­tries who formed a first-of-its-kind autism genet­ics con­sor­tium. The Project began in 2002, when researchers from around the world came togeth­er to share their sam­ples, data and exper­tise to facil­i­tate the iden­ti­fi­ca­tion of autism sus­cep­ti­bil­i­ty genes.

The fund­ing to the Cana­di­an team which pro­vid­ed lead­er­ship in the iden­ti­fi­ca­tion and analy­sis of these genes came from pub­lic and pri­vate part­ners includ­ing major awards and sup­port from Genome Cana­da through the Ontario Genomics Insti­tute, the McLaugh­lin Cen­tre, the Cana­di­an Insti­tutes of Health Research, the Cana­di­an Insti­tute for Advanced Research, the Cana­da Foun­da­tion for Inno­va­tion, the Min­istry of Research and Inno­va­tion, the Ontario Inno­va­tion Trust, the Cather­ine and Maxwell Meighen Foun­da­tion, the Pre­mier’s Sum­mit Award in Med­ical Research, Autism Speaks, The Cen­tre for Applied Genomics, the Che­do­ke Health Cor­po­ra­tion, the May­ber­ry Fam­i­ly Fund, the Hamil­ton Health Sci­ences Foun­da­tion and Sick­Kids Foun­da­tion.

Pin­to was sup­port­ed by fel­low­ships of the Nether­lands Orga­ni­za­tion for Sci­en­tif­ic Research and the Roy­al Nether­lands Acad­e­my of Arts and Sci­ences.

About The Hos­pi­tal for Sick Chil­dren (Sick­Kids)
The Hos­pi­tal for Sick Chil­dren (Sick­Kids) is rec­og­nized as one of the world’s fore­most pae­di­atric health-care insti­tu­tions and is Canada’s lead­ing cen­tre ded­i­cat­ed to advanc­ing chil­dren’s health through the inte­gra­tion of patient care, research and edu­ca­tion. Found­ed in 1875 and affil­i­at­ed with the Uni­ver­si­ty of Toron­to, Sick­Kids is one of Canada’s most research-inten­sive hos­pi­tals and has gen­er­at­ed dis­cov­er­ies that have helped chil­dren glob­al­ly. Its mis­sion is to pro­vide the best in com­plex and spe­cial­ized fam­i­ly-cen­tred care; pio­neer sci­en­tif­ic and clin­i­cal advance­ments; share exper­tise; fos­ter an aca­d­e­m­ic envi­ron­ment that nur­tures health-care pro­fes­sion­als; and cham­pi­on an acces­si­ble, com­pre­hen­sive and sus­tain­able child health sys­tem. Sick­Kids is proud of its vision of Health­i­er Chil­dren. A Bet­ter World.™ For more infor­ma­tion, please vis­it www.sickkids.ca.

About the Uni­ver­si­ty of Toron­to
Estab­lished in 1827, the Uni­ver­si­ty of Toron­to has one of the strongest research and teach­ing fac­ul­ties in North Amer­i­ca, pre­sent­ing top stu­dents at all lev­els with an intel­lec­tu­al envi­ron­ment unmatched in depth and breadth on any oth­er Cana­di­an cam­pus. With more than 75,000 stu­dents across three cam­pus­es (St. George, Mis­sis­sauga and Scar­bor­ough) and over 450,000 alum­ni active in every region of the world, U of T’s influ­ence is felt in every area of human endeav­our. www.utoronto.ca

About McMas­ter Uni­ver­si­ty
McMas­ter Uni­ver­si­ty, one of four Cana­di­an uni­ver­si­ties list­ed among the Top 100 uni­ver­si­ties in the world, is renowned for its inno­va­tion in both learn­ing and dis­cov­ery. It has a stu­dent pop­u­la­tion of 23,000, and more than 140,000 alum­ni in 128 coun­tries.

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For more infor­ma­tion, please con­tact:

Matet Nebres
The Hos­pi­tal for Sick Chil­dren
416–813-6380
matet.nebres@sickkids.ca

Suzanne Gold
The Hos­pi­tal for Sick Chil­dren
416–813-7654, ext. 2059
suzanne.gold@sickkids.ca

Paul Can­tin
Uni­ver­si­ty of Toron­to Temer­ty Temer­ty Fac­ul­ty of Med­i­cine
416–978-2890
paul.cantin@utoronto.ca

Veron­i­ca McGuire
McMas­ter Uni­ver­si­ty
905–525-9140, ext. 22169