Children with rare diseases in England are among the first in the world to be receiving a form of pioneering DNA testing which could more than double the chances of diagnoses - thanks to scientists at the University of Exeter.
In just a single test, whole exome sequencing looks for thousands of rare conditions by identifying genetic mutations in a patient's DNA.
It can improve and speed up diagnoses of children with rare diseases, of which there are between 6,000 and 8,000 known ones.
80% of these have a genetic factor.
NHS England hopes up to 700 children will benefit from the tests each year.
Since they were first rolled out on the NHS on 1 October 2019, 80 babies and children have been tested - just under half have received diagnoses.
It's being offered to children in neonatal or paediatric intensive care units when it's suspected they have a genetic condition.
The test, delivered by the South West Genomic Laboratory Hub, costs around £2,000 and has the potential to more than double the chance of a successful diagnosis.
How does it work?
- It looks for mutations in pieces of an individual's DNA that provide instructions for making proteins, usually taken from a blood sample.
- The majority of disease-causing variants are thought to lie within these regions, known collectively as the exome.
- The technique is faster than standard genetic tests.
The new testing can also show which patients are unlikely to respond to certain treatments.
This could prevent children from having to take unnecessary medication and experience the potential side effects.
Henry Dunn from Exeter had the new test at 20 months old after he experienced a range of undiagnosed problems and a spell in hospital after he was born.
Within a week of having the pioneering treatment he was diagnosed with a rare disease - Costello syndrome - than can affect several organ systems and lead to an increased risk of childhood cancer.
He was closely monitored and after developing cancer twice, it was detected early enough and successfully treated on both occasions.
Henry is now in remission. His mother, Lauren Dunn, said that without the exome sequencing, her son's diagnoses and treatment "would likely have been delayed."
NHS England has high hopes for its future.
Heath Secretary Matt Hancock is also optimistic.