Fast genetic tests let doctors diagnose a baby's critical illness

New Zealand doctors and scientists used high-speed genetic testing to diagnose a critically-ill baby.

A study published in the American Journal of Medical Genetics shows how rapid whole genome sequencing was used to diagnose the rare disease of a baby in neonatal intensive care at Auckland City Hospital.

Within 72 hours, the results showed a genetic mutation linked to an extremely rare disease called Baraitser-Winter syndrome, which affects the development of many parts of the body, including the face and the brain.

“Fewer than 100 cases of the disease have been reported worldwide and sadly Baraitser-Winter syndrome is not curable,” said Professor Frank Bloomfield, director of the University of Auckland’s Liggins Institute, which leads New Zealand’s research into pregnancy and babies.

“In this case, the testing gave the family certainty, and avoided unnecessary medical procedures, letting her parents spend as much time with her as possible.”

The Liggins Institute is looking at the potential for New Zealand to offer this type of testing routinely.

The case demonstrates “the value of rapid whole genome sequencing in the diagnosis of rare disorders in critically ill newborns,” Professor Bloomfield and his colleagues wrote in the genetics journal. “Rapid diagnosis provides certainty for the family in highly stressful situations in which they often are expected to contribute to major decisions about provision of care,” they said.

In the case of the critically ill child, doctors sent blood samples from the baby and her parents to Australia for analysis. (Differences between the genomes of the parents and the child can help in identifying an illness.)

“While the Covid-19 pandemic familiarized the public with rapid genomic tests for tracing chains of infection, people know much less about the potential for improved medical treatment,” says Professor Bloomfield.

The team led by Professor Bloomfield, included Dr Kristina Sibbin and colleagues from Auckland City Hospital along with academics from the university’s School of Biological Science, and the Liggins’ Professor Justin O’Sullivan and Dennis Nyaga.

The sequencing and analysis were carried out by the Victorian Clinical Genetics Service in Australia.

Each year, hundreds of children in New Zealand are born with critical illnesses which defy diagnosis. With 7,000 rare diseases in existence, even doctors with decades of experience can be stumped when a newborn is struggling for survival.