The parents of Charlie Gard, the baby at the centre of a high-profile legal battle, say they are planning to start a charity with the money they raised for his treatment.

Charlie Gard died on 28 July a week short of his first birthday, as a result of a rare condition called mitochondrial depletion syndrome.

His parents, Chris Gard and Connie Yates, had raised £1.3m via the fundraising platform GoFundMe to take him to America for experimental treatment, but Great Ormond Street Hospital, which was treating the baby, objected, saying the treatment was unlikely to help. Gard and Yates appealed to the High Court against a ruling that treatment should be withdrawn and that Charlie should be allowed to die, but eventually conceded that nothing could be done for him.

Today in a statement on their campaign website, Gard and Yates thanked donors for their support and announced their plans for the money which had been donated.

“In the following weeks we will be setting up The Charlie Gard Foundation: a foundation that will help other children with mitochondrial diseases, and rare childhood illnesses,” the statement said.

The charity will fund research on rare medical conditions, as well as providing information for parents in a similar situation on parental rights and the availability of treatment and expert clinicians.

The statement said: “All existing donations from our GoFundMe fundraising account – and any new donations – will now go towards Charlie’s foundation.”

Go Fund Me has contributed an extra £10,000 to the fund, the statement said, describing the donation as “a wonderful gesture”.

The statement said: “We feel that the foundation will be a lovely legacy for Charlie, and we hope that you will all continue to support us in honouring the life of our little warrior as he helps other poorly children and their families.”

A GoFundMe spokeswoman confirmed its donation but declined to comment further.