TWO OXFORD siblings took to the stage with A-list celebrities last week at a gala held by an American children's charity.

Ace and Sky Manthey have been involved with the UK branch of the American charity, Over the Wall, since Ace was diagnosed with acute lymphoblastic leukaemia when he was three years old.

The audience of nearly 500 at the SeriousFun Children’s Network Gala at the Roundhouse in London included Jude Law, Game of Thrones’ actor Aiden Gillen and TV presenter Natalie Pinkham who was the MC for the evening.

Ace is now 11 and in remission, and along with his Sky was chosen by Over the Wall to appear with others on stage at the star-studded gala, performing renditions of upbeat pop songs like Miley Cyrus’ 'The Climb' and Katy Perry’s 'Firework'.

Over the Wall provides children with serious illnesses the opportunity to be kids again by offering free summer camps across the country.

Their father Ian Manthey heard about the camps while Ace was in John Radcliffe Hospital receiving chemotherapy. He decided to enrol Ace’s sister Sky in a sibling camp that provides support and engagement for children whose siblings are battling diseases.

He said: “Sky was shy and reluctant to go but she was transformed at camp. Before she wasn’t very confident. But afterwards she was taking the lead in the school plays.”

Seeing what a positive impact the experience had on Sky, he decided to enrol Ace in a camp when at eight years old.

He continued: “He had the best time of his life. He asked if he could go on another camp straight away. There is a picture of him holding a bow and arrow. He has jeans on and mud on his face. Anyone looking at that picture would just see a kid who is happy—but to me, I saw that was the first real smile on Ace I had ever seen. He had a real proper smile.”

The umbrella organisation, SeriousFun, was founded by actor Paul Newman in 1988. There are over 30 camps and programmes around the world to support and encourage children faced with immeasurable strife and allow them to enjoy themselves surrounded by those who understand their struggle.

Clea Newman, director of special initiatives for SeriousFun and Newman's youngest daughter, said: "I am utterly thrilled to have been part of such a special event. Ace, Sky and all the campers involved made it an evening to remember. More importantly, they have helped us to raise money which will go directly to helping provide hundreds of children living with serious illness the chance to have some fun and, in my father’s words, 'raise a little hell' at a SeriousFun children’s camp."