In February 2017, GOSH asked the High Court to override the parents' decision, questioning the potential of nucleoside therapy to treat Charlie's condition.

In July 2017, after receiving a letter signed by several international practitioners defending the potential of the treatment and claiming to provide new evidence, GOSH applied to the High Court for a new hearing.

The case attracted widespread attention in Britain and around the world, with expressions of concern and assistance offered by figures including then U.S. President Donald Trump and Pope Francis.

[11]: 45, 58  By November, the doctors suspected that he had mitochondrial DNA depletion syndrome (MDDS), a set of rare diseases caused by mutations in genes essential for mitochondria to function.

[11]: 82  On 13 January, the GOSH doctors informed Charlie's parents that the brain damage had made the experimental treatment futile, and in light of the risk that he was suffering, they withdrew their support for it.

In June, immediately after the High Court had ruled that artificial life support should be withdrawn, the parents said that they wanted to take their son home to die or to bring him to a hospice, and that GOSH had denied this; the hospital would not comment due to Charlie's confidentiality.

[28] Congressmen Brad Wenstrup and Trent Franks announced that they intended to introduce legislation granting lawful permanent resident status in the U.S. to Charlie Gard and his family.

"[29] Trump said the U.S. would be "delighted to help",[9][30][31] Pence called Charlie's case "heartbreaking" and said that "the American people oughta [sic] reflect on the fact that for all the talk on the left about single-payer, that's where it takes us".

[28] The case was cited in the American press and social media as evidence in the debate there about the Administration's promise to repeal the Patient Protection and Affordable Care Act (Obamacare).

[note 1] In a letter that was made public, was presented to and rejected by the Court of Appeal and was sent to GOSH, Hirano and other doctors claimed to be able to provide new evidence to support the view that Charlie should be given nucleoside treatment.

In a public statement, GOSH explained why it had applied: "Two international hospitals and their researchers have communicated to us as late as the last 24 hours that they have fresh evidence about their proposed experimental treatment.

In its application to the High Court for a second hearing GOSH said that the parents, through their solicitors "not for the first time raised the prospect of criminal proceedings against the hospital and its staff".

[11][61] Charlie was joined as a party and a guardian ad litem was appointed under the Children and Family Court Advisory and Support Service (CAFCASS).

He described his work with people and mice with the TK2-mutation form of MDDS, reporting that the patients under the treatment improved muscular strength, becoming less dependent on ventilators, and did not develop seizures compared to those not receiving nucleoside supplements.

[11]: 68, 113–115 [64] The court appointed guardian testified that because of the risk that Charlie was in pain, and the low chance that the treatment would work, it was in his best interests to withdraw mechanical ventilation.

[66] In a "Category 1" case the parents who oppose the course of treatment for which the treating clinicians apply, and do not have a viable alternative therapeutic option to put before the court.

[66]: 57, 58  The distinction that would lead a case to be allocated to "Category 2" is that a viable alternative treatment option is put forward by the parents and the court is, therefore, required to choose between the two.

"[66]: 113  Of the "wholly new point of law" Lord Justice McFarlane said "If, contrary to my primary reading, Mr Justice Baker did intend to state, where a parent puts forward a viable option for treatment, that the High Court only has jurisdiction to interfere with a parent's choice of that medical treatment if the child is likely to suffer significant harm as a result, then, in my view, such a statement has no foundation as a matter of law, is contrary to established authority and is therefore plainly in error.

The Supreme Court had said at its earlier hearing that it had no authority in respect of a Declaration, additionally the application to stay caused it to face the unique dilemma of, in effect, acting against Charlie's best interests.

By consent, the reporting restrictions of his identity were lifted and he agreed to travel to London to examine Charlie and to take part in a conference with the GOSH medical team and other experts.

Mr Justice Francis arranged to hear further evidence after a medical conference of experts from around the world, including Hirano had been conducted on 17 July.

[43]: 13, 14  On 24 July, the barrister representing Chris Gard and Connie Yates withdrew their request to fly their son to New York and their challenge to withdrawing mechanical ventilation and proceeding with palliative care.

[78][79] On 24 July, Mr Justice Francis said "Given the consensus that now exists between parents, the treating doctors and even Dr Hirano, it is my very sad duty to confirm the declarations that I made in April this year, and I now formally do so.

The parents accused GOSH of delaying treatment until it was too late, with the mother complaining that the world-renowned children's hospital had "wasted time" in refusing to allow doctors from abroad to treat her son.

The High Court judge described these comments as "nonsensical", adding that "it was one of the pitfalls of social media that the watching world felt it right to have opinions without knowing the facts of the case".

[93] In the US the medical establishment handles these requests under "expanded access" or "compassionate use", which examines whether there is a reasonable chance of more benefit than harm for the patient; the extent of need; fairness; and the resources of everyone involved, including the people providing and administering the drug.

He argued that many children were being kept alive by artificial ventilation and that the accompanying pain and discomfort, which could be ameliorated, was not sufficient reason to override the parents right to decide.

"[1][2] It has been argued that the case had a negative impact on distributive justice, as Great Ormond Street Hospital incurred legal costs of £205,000, including VAT (money diverted from medical care to lawyers), and that distributive justice could be harmed further if proposed reforms known as 'Charlie's Law' (which would replace the best interests test with a significant harm test) are enacted.

Lady Hale in the Supreme Court "By granting a stay, even of short duration, we would in some sense be complicit in directing a course of action which is contrary to Charlie's best interests.

Put simply, this is about a sweet, gorgeous, innocent little boy who was born with a rare disease, who had a real, genuine chance at life and a family who love him so very dearly, and that's why we fought so hard for him.