Health-care specialists in Montreal are trying to understand why such a high number of autistic children come from immigrant families, a phenomenon seen in major cities across North America.

Autism, or autistic spectrum disorder, is a neuropsychiatric disorder that affects aptitude for communication and personal interaction.

Some evidence suggests the autism rate among new Canadians is high, but there is little research to understand why, as immigrant families struggle with a chronic shortage of autism services as well as language and cultural challenges.

In Montreal, a clinician said more than half the children enrolled in rehabilitation services come from immigrant families.

"Maybe we can help the children earlier in their life, and then we'll have less action to do when they are older," said Dr. Andre Masse, who runs one of the city's largest clinics for children, connected to the University of Montreal.

Dr. Vikram Dua with the British Columbia Autism Assessment Network said he also sees a lot of children of immigrants at his Vancouver clinic,but is cautious about drawing conclusions.

"'Families who are immigrants, they tend to be younger," said Dua. "They tend to have more children compared to the non-immigrant population."

Masse will ask the Quebec government for help funding research on the topic. One of the first studies, an international paper that includes children enrolled in schools in Montreal, will be published later this year.

In the meantime, a centre in Montreal is helping immigrant families navigate the health-care system.

"They are very anxious about the future of their children," said Teresa Penafil of the centre. "They do not necessarily at the beginning understand what it means to be autistic."

Montreal resident Jennifer Trinh, 9, has a severe form of autism and has been on a waiting list for rehabilitation care for more than two years.

"That's a very bad situation," said Jennifer's father, Anh Hoa Trinh, wincing at the thought of waiting much longer.