Giving out the new behavioural signs of autism spectrum disorders (ASD), scientist now say that about half of all cases of the disorder may be diagnosable at about one year of age, the earliest the disorder has ever been diagnosed.

After evaluating the social and communication development in ASD from 14 to 36 months of age, researchers from the Kennedy Krieger Institute in Baltimore, Maryland found that approximately half of all children with autism can be diagnosed around their first birthday.

Lead author Dr. Rebecca Landa, director of Kennedy Krieger's Center for Autism and Related Disorders, said in a news release: "The fact that we can identify this at such a young age is extremely exciting because it gives us an opportunity to diagnose children with ASD very early on when intervention may have a great impact on development."

The study, which is published in the Archives of General Psychiatry, followed 107 children considered at high risk for autism spectrum disorders. They all had a brother or sister with autism while 18 children studied had no family history of the disorder.

According to WebMD, the researchers have asked the parents and pediatricians to lookout for the following signs of the disorder in toddlers:

- Abnormalities in initiating communication with others: Rather than asking for help with something, the child may struggle alone without looking around for assistance.

- Impaired ability to initiate and respond to opportunities to share experiences with others: Children with autism may not follow their parents gaze or initiate contact with others.

- Irregularities when playing with toys: Instead of using a toy as it is meant to be used, like picking up a toy fork and pretending to eat with it, the child may do something unusual with the toy.

- Significantly reduced variety of sounds, words, and gestures used to communicate: Compared with typically developing children, children with autism have a much smaller inventory of sounds, words, and gestures that they use to communicate with others.