Kyle Sell is nearly 5, but he has never talked, does not know his own name and has only just moved from a cot to a bed.
More than 30 psychologists, paediatricians, dieticians and occupational therapists have been in and out of his life - but not one of them has been able to tell his mother Jenny what is wrong with him.
She and the rest of the family have moved around the country trying four different district health boards - including Capital & Coast and Hutt Valley - in an effort to find answers and support.
He could manage only "pre-talking babble", had trouble eating and sleeping, and could not walk until he was 2 , Mrs Sell said.
The hardest time was when he was upset and unable to be reasoned with.
"Most of the time I don't know what's wrong with him, and I'm his mother."
The lack of diagnosis for Kyle made it hard to get the right support. "Medically he is very well, so I am blessed. But [people] have no idea what he's like to manage."
Many people assumed he had autism, she said, but doctors had told her his late development was not typical of an autistic child.
At one point Mrs Sell, who is a paediatric nurse, thought his characteristics indicated the neuro-genetic disorder Angelman syndrome, but all genetic testing came back clear.
"There's a lot of guilt there as well. As a mum you wonder, what did I do wrong?"
She kept being told to grieve over the child Kyle could have been.
"[But] I feel I will never be able to move on from that grief because it's in my face the whole time.
"I have this little boy I have to love. As a mum, as a family, it absolutely runs our life."
But Kyle was still her boy who loved music, had recently had a "real breakthrough" in being able to climb ladders, and loved to jump on the trampoline with his 7-year-old sister.
People often complimented her on her blond-haired, "normal"-looking boy, but "what's going to happen when he's no longer cute?" she said.
The family, now based in Auckland, continue the quest to get more support and guidance for schooling options for Kyle.
Mrs Sell worries that he may never be able to cope in mainstream schooling, and does not know what his future holds once he turns 5 in July.
He is not yet toilet-trained and screams at the sight of a potty.
"My boy is going to need more than an hour with a teacher aide a day."
- The Dominion Post
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