The parents of a boy with a rare genetic condition are returning to court in an 18-month legal battle to get him a "life-changing" drug on the NHS.
The seven-year-old, known only as Child A, has phenylketonuria (PKU), which means his body cannot process an amino acid found in most protein-rich foods.
He also has severe autism which means he has issues eating the specific foods he needs, leading to dangerous levels of protein in his blood.
If left untreated the condition can cause brain damage and irreversible disabilities.
Doctors treating the boy at Birmingham Children's Hospital have advised that he should be prescribed a drug known as Kuvan, which would reduce the danger and let him lead a more normal life.
NHS England has refused to give him the expensive treatment, which it says is not cost-effective.
His family has been battling the decision in the courts since October 2016.
The boy's father previously branded the decision "extremely frustrating, unfair and inhumane" and added: "No family should have to fight with the NHS for over 18 months to ensure that their child is given proper treatment.
"It is clear to me they do not want to fund this life-changing drug."
Professor Anita MacDonald, consultant metabolic dietitian at Birmingham Children's Hospital, said it has brought "appalling strain" to the family and added: "The NHS' refusal to provide the treatment is not in the best interests of the child."
Eric Lange, chairman of the National Society for Phenylketonuria, described the decision as "shocking and inhumane" and accused the NHS of "failing people with PKU in the UK".
"The UK is one of the few countries not using BH4 (Kuvan), which is widely used across the EU and even in lower income countries such as Russia and Bulgaria," he said.
The case is due before Dame Geraldine Andrews at London's High Court on Tuesday for a two-day review hearing.