A coroner has said not providing a blood test for an ill boy was "a failure to provide basic medical care".
Callum Cartlidge died after he suffered a cardiac arrest at home in Redditch, Worcestershire, on 3 March 2017.
He was discharged from Worcestershire Royal Hospital the previous day with a diagnosis of gastroenteritis.
Recording a narrative verdict, the assistant coroner said the eight-year-old's death could have been prevented if a blood test had been done.
Assistant coroner David Reid said while not carrying out the blood test was a "serious failing", it was not a gross failing and he could not record a verdict of neglect .
Worcestershire Coroner's Court heard if the illness had been identified on 2 March Callum would have survived.
He had been suffering an Addisonian crisis, linked to undiagnosed Addison's Disease.
A medical expert told the inquest the test would have identified Callum's rare disease.