As the fastest growing and most commonly diagnosed neurological disorder in Canada, there's a rising awareness of autism among parents.

Developmental pediatrician at Holland Bloorview Kids Rehabilitation Hospital Dr. Melanie Penner says each child who falls on the autism spectrum is unique, and signs of the neurological disorder could begin to present themselves at different ages.

However, she noted that experts in diagnosing autism focus on two areas: social interaction and communication, and restricted or repetitive behaviours.

She said some signs of autism can become apparent as babies begin to play.

"How (are children) playing? Do they want to get their parents to play with them? Are they doing imaginative play, like giving stuffed animals a bath?" Penner told CTV's Canada AM on Tuesday.

Other signs parents can look for include:

  • Difficulty making eye contact
  • Not responding to their name
  • Trouble using body gestures or body language to communicate, such as pointing
  • Repetitive movement, such as flapping their hands
  • Resistance to any change in their routine. For example, do they want to eat the same meal, or eat off the same plate every day
  • Difficulty coping with bright lights or loud noises

Penner said if parents are concerned that their child may be showing signs of autism, it's best to seek medical advice as soon as possible.

"We know that these interventions are more effective at younger ages," she said. "We may be missing a window of time when (their) ability to learn those things is higher than it may be at older years."

Mom of two sons with autism speaks out

Toronto mom Susan Cosgrove said she noticed "differences" in her son Liam shortly after his second birthday.

"Behaviour-wise, he was having a hard time," Cosgrove told CTV's Canada AM. "There was a lot of screaming and not really being able to understand why he was screaming or letting us know what was bothering him."

Cosgrove said she decide to bring up her concerns with her doctor when she noticed that Liam had no interest in socializing with other children during play groups.

She said getting an autism assessment took so long that Liam was not diagnosed until he was three-and-a-half.

Cosgrove said, years later, when she had her second son Phoenix in 2013, he began regular developmental assessments at six-months-old.

At 18 months, she said doctors "flagged" Phoenix for autism.

"There were concerning behaviours," she said. "Things like his rigid play skill. He was very obsessed with numbers and reading and words, and it's very hard for him to go outside of these interests when he plays.”

While she had already gone through a similar experience a decade earlier, Cosgrove said Phoenix’s autism diagnosis came as a complete surprise.

"I just thought he was a really bright, very focused little guy," she said. "Having raised Liam, I really thought I would know, but they're so different."

Cosgrove said, over the years she's found herself becoming "an unexpected advocate," helping other parents who are going through a similar experience.

She shares her story and offers resources for parents on her blog The Possibility Parables.

"If they do end up with a child who receives a diagnosis…there are a lot of different emotions coming very quickly and everyone feels them very differently."