A revolutionary blood test is set to change how rare genetic diseases are diagnosed in infants and children, providing results in less than three days and possibly removing the necessity for invasive procedures.

Presented at the European Society of Human Genetics conference, this test needs just 1ml of blood, which is much less invasive than procedures such as muscle biopsies that often require general anesthesia in young patients.

While rare diseases are, the name suggests, uncommon — there are over 7,000 rare diseases affecting an estimated 300 million people globally.

Numerous individuals remain undiagnosed throughout their lives because of inconclusive tests, while others endure waiting for years or even decades to obtain precise results.

By incorporating samples from both parents — a method known as trio analysis — this game-changing test can distinguish between carriers and affected parties with greater accuracy and speed.

“The ability to use so little blood from infants and to produce robust results with a rapid turnaround time has been revolutionary to families,” co-author Dr Daniella Hock, a senior postdoctoral researcher at the University of Melbourne, Australia, said in a press release.

“Moreover, the use of familial samples for trio analysis greatly improves the differentiation between carrier and affected individuals with higher confidence, and that has exceeded our initial expectations. We believe that the use of this test in clinical practice will bring considerable benefits to patients, their families and to healthcare systems by reducing the diagnostic time.”

Beyond providing swift diagnoses, the test offers families access to appropriate treatments, prognoses and reproductive options to prevent the recurrence of disease in future pregnancies.

For healthcare systems, this single analysis could replace a battery of targeted tests, leading to reduced costs and earlier interventions.

“Non-invasive agnostic approaches such as genome sequencing and protein analysis will allow us to reach a diagnosis more rapidly in the future,” Professor Alexandre Reymond, chair of the conference, said.

“They will also permit the solving of previously unsolvable cases, thus helping families worldwide.”

This advancement aligns with global efforts to enhance early detection of genetic conditions.

For instance, NHS England is launching a scheme to screen 100,000 newborns for over 200 genetic conditions through whole genome sequencing.

And researchers at Columbia University have created a rapid test that accurately detects whether a fetus has extra or missing chromosomes — the test costs as little as $50 to run and the results are returned within hours.