Rapid Blood Test Diagnoses Thousands of Rare Genetic Diseases

Although rare genetic diseases are uncommon, there are over 7,000 different diseases caused by mutations in more than 5,000 known genes, affecting around 300 million people globally. Despite their rarity, these diseases can leave about half of all patients with a suspected rare disease undiagnosed. Current diagnostic methods for these undiagnosed conditions are typically slow, often focused on specific diseases, and not always sensitive enough. As a result, affected individuals and families may experience years or even decades of inconclusive tests and invasive procedures, which can cause significant distress. Now, a new rapid testing method is expected to significantly improve the diagnosis of rare diseases in infants and children, according to research published in Genome Medicine.

Researchers from the University of Melbourne (Victoria, Australia) and the Murdoch Children's Research Institute (MCRI, Parkville, Australia) have developed a blood-based method capable of analyzing thousands of proteins in a single, untargeted test. Most genes contain the DNA sequence that provides the instructions for producing proteins, which are the molecular machines in cells and tissues. What makes this test unique is that it sequences proteins instead of the genes themselves. This data helps scientists understand how changes in the gene sequence can affect the corresponding protein’s function, potentially leading to disease. The test is versatile, applicable to thousands of different diseases, and even capable of detecting new, previously unidentified diseases by offering the evidence needed to confirm that a genetic alteration is the likely cause.

Not only is the proteomic test fast, but it is also minimally invasive. It requires just 1ml of blood from infants, with results available in less than three days for patients in urgent care. For patients, this molecular diagnosis means quick access to appropriate treatment, if available, as well as a prognosis and an end to a long series of invasive tests. For families, receiving a diagnosis can provide options for preventing the disease in future pregnancies through prenatal or preimplantation genetic testing. Healthcare systems also benefit, as this method replaces multiple targeted tests with a single analysis, reducing healthcare costs by minimizing the need for extensive testing and enabling early intervention with the right treatment. The researchers hope that this test will become a standard part of diagnostic procedures for rare and other genetic diseases in clinical laboratories.

“The ability to use so little blood from infants and to produce robust results with a rapid turnaround time has been revolutionary to families,” said Dr. Daniella Hock, a Senior Postdoctoral Researcher at the University of Melbourne. “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.”