Scientists at Auckland University's Centre for Brain Research say they have gained new understandings of the causes of autism, opening up new avenues for possible treatment.
The ground-breaking research, done in collaboration with Stanford University in the United States, looked at brain cell communication and genetic mutations in people with autism.
The team discovered that autism was caused by mutated brain proteins, called Shank3, weakening communication between brain cells.
Head researcher Jo Montgomery said that the discovery was exciting because it meant treatments could be investigated.
"Brain cells are incredibly sociable cells in the brain and they talk to each other all the time," she said.
"There are about 10 trillion brain cells connected by about 10 billion synapses which gives you an idea of how much chatter is going on in your brain at one time, and all that chatter underlies how you see things, how you move, how you learn and how you remember things.