As experts call for more UK research into the causes and treatment of autism, BBC News Online talks to the mother of a nine-year-old autistic boy.
Autism tends to be picked up in toddlers
Anna Parton, from Bromley, Kent, had to spend £12,000 and devise her own care plan to give her son Robert the help she felt he needed.
She was devastated when Robert was diagnosed with autism at age three.
But she said: "I really knew from when he was about 10 weeks old that there was something wrong.
"He was very, very good and very, very quiet.
"He smelt funny, I know it sounds strange but I'm a dietician and I thought it must be a metabolic disorder.
"When Robert was two, he barely spoke and didn't understand what I was saying. He would go up to things and lick them, or smell the ground.
"I asked my health visitor, my peers and people at work what they thought was wrong, but all of them said 'oh don't worry, he's just little, don't be silly'."
'No sense of danger'
Anna added: "I had to push for speech therapy - we were told we had to wait 18 months for the first appointment. By then he was almost three.
"I got into internet research. When I typed in 'speech problems' I got about 100,000 results, I thought 'where do I start?'
"By the time we went to speech therapy he was screaming for most of the day - that was his main form of communication.
"If he didn't like you he would pee on you, or hit you.
"He had no sense of danger. Once we were at the beach and he just started running into the sea, with all his clothes on, and didn't stop.
"My husband found it hard at work, and my older son was affected - Robert would come into his room and rip all his toys up.
"I used to get comments from people like 'that child needs a good smack'.
"I thought I was the worst parent in the world. I thought I had done something horribly wrong to create this monster.
"When I began to suspect Robert was autistic, we were told it would be two-and-a-half years before we could get a proper diagnosis, and without one you're stuffed.
"The emotional needs of the family are completely overlooked, you get nothing compared to families coping with something like cancer."
She said there were just two NHS autism workers in Bromley.
"Robert was diagnosed when he was three, only because we jumped up and down and pushed and pushed them, so we managed to jump the queue.
"The system absolutely stinks.
"Once we got a diagnosis we could tap into people. No-one could help us until we got it.
"I took a career break and worked with Robert for almost four years at home.
"I went on every course known to man. These are expensive - the Son-Rise programme in Boston, US, alone cost $1,000 a day.
"Parents of autistic children are desperate. You'd go naked in the high street if it could help your child.
"Because there isn't much research, even the consultants can't help you.
"Suddenly you have to become an expert."
Anna developed her own one-on-one programme to help Robert, and recruited volunteers to help her.
They gave Robert around 10,000 hours of therapy over three years.
"We were doing a child-centred, child-led programme, based on play.
"We started out by just watching him, then copying what he did.
"Eventually he started to notice and altered his behaviour to include us, and allow us to join in with his play."
She said: "We wanted to carry on, but when he was seven he actually said 'Mummy I want to go school now'."