A genetic test to predict a baby’s risk of developing autism has been developed by Melbourne researchers, paving the way for earlier intervention to improve behaviour and functioning.

Neuropsychologist Renee Testa said children were often diagnosed with autism at age three or four and only after there was ”a significant and negative impact on a child’s level of functioning”.

She said in some instances clinicians still had doubts about whether a child had autism and needed to monitor their behaviour over another year.