Hollywood's Iron Man star Robert Downey Jnr is leading a campaign to raise awareness of a rare disease affecting a Kent girl.

Little Leah Baldock is only nine but has already spent most of her life in and out of hospital.

The schoolgirl from Sittingbourne suffers from a rare and life-threatening condition called Rohhad Syndrome of which there are only 100 confirmed cases in the world.

The Rohhad Syndrome Awareness video

It makes healthy children gain weight, attacks the automatic nervous system which controls breathing and the heart and affects hormones.

Leah has taken part in a promotional video raising awareness of the disease, featuring Hollywood star Downey Jnr.

Leah's Sheppey-born mum Michelle said: "We first knew something was wrong when Leah was three. But we had to fight to get anyone to take us seriously."

Leah, who goes to Minterne Community Junior School, needed an eight-hour operation to remove a tumour and has been in and out of hospital ever since.

The disease keeps her awake at night and leaves her with chronic exhaustion.

Dad Mark, who runs his own roofing company from the family's home in Peony Crescent, Eden Village, Sittingbourne, said: "Leah went years without a proper diagnosis until we ended up at Great Ormond Street Children's Hospital.

"It is vital awareness of this condition is raised so other children don't have to wait so long. More research is needed."

American actor Robert Downey Jnr signed up to the campaign after getting a letter from Scottish sufferer Aaron Hunter whose mum and dad Elisabeth and Ian founded the Rohhad Association.

On Friday five-piece band Marylebone Jelly headline a charity concert at The Appleyard, formerly the UKP Leisure Club, in the Avenue of Remembrance, Sittingbourne, to raise funds for the association.

The show is the brainchild of Michelle's friend Heather Attwell.

She said: "I watched a video on the Rohhad website which features Leah and cried my eyes out. These poor children have to suffer so much.

"Because the video effected me so much I felt I had to do something and organised the charity night."

Marylebone Jelly's lead singer Ed Austin said: "Rohhad is a life-threatening, complex and rare condition with many symptoms including rapid-onset obesity. Many children do not make it to adulthood. With research, we may find a cure for lovely Leah and all the other brave children."

Rohhad is an acronym of rapid-onset obesity (RO), hypothalamic dysregulation (H), hypoventilation (H) and autonomic dysregulation (AD).

Dance tickets are £10 from The Appleyard on 01795 427852.

For details about the condition, visit www.rohhadassociation.com.