A boy who already has one of his grandmother's kidneys is set to have another transplant operation - thanks to his mum.

Nine-year-old Mark Bailey had his first transplant operation five years ago.

But recent tests have revealed he has started to reject the kidney his grandmother, Kathleen, donated to him.

His mum, Andrea, of Larch Road, Guisborough, is now undergoing tests to see if her kidney is compatible with her son.

She said: "I've had lots of tests and there's only one more to go.

"Then it will be a case of being on stand-by until Mark gets really ill and the operation goes ahead.

"It's strange because he is fine at the moment and full of energy and is very fit.

"But the doctors think it could be just before or just after Christmas when he starts rejecting the kidney more."

Mrs Bailey has managed to explain what is going on to Mark, who was too young to understand the first transplant operation.

She said: "We knew he would need another transplant at some time but we hoped he would be older, maybe with a family of his own.

"It is a lot for us all to go through but we are ready for it.

"Mark thinks once he has one of his mum's kidneys he'll be fine."

Meanwhile, life goes on as normal for Mark, who is a pupil at North Gate Junior School.

He hopes to compete in the transplant games in Newcastle next month, and will undergo tests just before the games.

If he is well enough, Mark plans to compete in a number of races, including the 50 metre dash.