A special school pupil with a complex condition has "come on in leaps and bounds" since using a new form of picture communication.

Zakari Simpson, who cannot swallow, has made real progress thanks to the introduction of a new method of communication based on picture cards.

The Picture Exchange Communication System (PECS), taken up three months ago, has enabled eight-year-old Zak, who suffers from behavioural problems similar to autism, to make himself understood by pointing at pictures of the things he wants.

Dad Gordon Mullaney, of Greaves Street, Little Horton, said: "He is coming on in leaps and bounds. We can have a reasonable conversation with him now and understand what he wants without him getting wound up.

"Before all we got were grunts and groans but now he can manage words and he is doing really well."

The communication system relies on a book of pictures used by the child to indicate what is wanted.

Now plans are underway at his school in Idle to create a personal book for Zak, incorporating photographs of his parents, belongings and favourite places to go.

Mr Mullaney said: "They have been to the house and taken pictures of things personal to Zak which they will put together into a special book for him."

The deputy head teacher at Greenfield, Zak's school, Ralph Penny-Larker, said: "We have seen a massive change in Zak since he started communicating through picture exchange.

"The idea is that they make sentences by looking through their picture book and pointing to the picture of what they want. It stops them getting distressed because people don't understand them.

"Zak's behaviour used to be quite challenging because he was getting frustrated but now it is far less so because he can communicate with the people around him."

Zak was featured in the Telegraph & Argus last year when his mystery medical condition was highlighted by an appeal for a home adventure playground for him. Medics warned his parents that food and saliva breathed onto his chest may have caused permanent lung damage and last year doctors admitted they may never find a name for the rare condition, which also causes behavioural problems similar to autism.

"They still don't know what it is," said Mr Mullaney, who works as a matchday steward at Bradford City's Valley Parade.

"But he's doing pretty well at the moment. The mild winter meant he only got six chest infections, which is a lot less than last year, and with the weather getting warmer he seems to be doing well at the moment."