Brave little Alex Herbert made his first tentative steps into the outside world yesterday since undergoing a bone marrow transplant to cure a rare genetic disorder.

The four-year-old from Barnard Castle has spent much of the last six months being treated for the disorder at Newcastle General Hospital's Bubble Unit.

Diagnosed as having XLP, the same virus that claimed the life of his brother in June, Alex was confined to an isolation "bubble" for weeks after the transplant.

The virus attacks the immune system, turning the most minor infection into a potentially lethal threat, and despite undergoing two bone marrow transplants, his seven-year-old brother Edward never recovered.

But despite the continual threat of infection, Alex is steadily recovering from the bone marrow donated from his older brother Michael, and could even be starting school within six months.

And yesterday he proved his determination to overcome the disorder by posing and smiling for a picture at Teesdale Sports Centre, in Barnard Castle.

Alex accepted a check for £1,000, from the Province of Durham Freemasons, on behalf of Newcastle General Hospital's Bubble Appeal, which helps children suffering from similar disorders as the Herbert's.

The sports centre is also raising funds for the appeal through the sponsored Channel Challenge.

The event encourages people to swim the equivalent length of the Channel in the centre's swimming pool, and both Alex's mother, Alyson, and brother Michael, have signed up.

But it was Alex's spirit and courage which put a smile on the faces of his parents yesterday, who admitted they were slightly nervous about his first public appearance since leaving hospital.

Mrs Herbert said: "He's been so brave, and it has given us all hope. He knows how bravely his brother Edward fought, and he is determined to get through this.

"He even puts an arm around me when I get upset, and every night before he goes to bed he looks up at the sky from his bedroom window and says goodnight to Edward.

"We're all determined to overcome this and the help and support we have received has been overwhelming."

To support the Bubble Appeal call Newcastle General Hospital, on 0191-267 5761.