New Protein-Based Blood Test May Speed Up Rare Disease Diagnosis: Study Shows

A new blood-based test could significantly accelerate the diagnosis of rare genetic diseases in babies and children, according to research presented at the annual conference of the European Society of Human Genetics. The method, developed by Dr. Daniella Hock and her team at the University of Melbourne, Australia, offers a fast, minimally invasive alternative to current diagnostic approaches, with results available in under three days.

While rare diseases are individually uncommon, they collectively affect about 300 million people worldwide. With more than 7,000 rare conditions linked to mutations in over 5,000 genes, diagnosing these diseases remains a challenge. Current testing methods are often slow, disease-specific, and lack sensitivity, leaving nearly half of suspected patients undiagnosed after years of invasive procedures and inconclusive results.

Dr. Hock's team has developed a proteomic test that analyzes thousands of proteins from just 1ml of blood. Unlike traditional genetic tests that examine DNA, this test sequences proteins—the functional products of genes—allowing scientists to see the downstream effects of genetic mutations. “The test is applicable to potentially thousands of different diseases, and it can even be used to detect new ones by providing the evidence needed to confirm that a genetic change is the likely cause of the disease,” says Dr. Hock.

“When the test is also performed on blood samples from parents we call it trio analysis. In recessively inherited conditions, this helps considerably in differentiating between carriers, who only have one copy of the defective gene, and the affected individual who carries two copies,” she adds.

For patients, a molecular diagnosis allows faster access to treatment and can end prolonged uncertainty. Families gain access to reproductive options like prenatal or preimplantation genetic testing. Health systems also benefit through cost savings by streamlining diagnosis and enabling early, targeted care.

“Our new test can identify more than 8,000 proteins in peripheral blood mononuclear cells (PBMCs) covering more than 50% of known Mendelian and mitochondrial disease genes, as well as enable us to discover new disease genes,” says Dr. Hock.

Reference: Santos Gonzalez F, Hock DH, Thorburn DR, Mordaunt D, Williamson NA, Ang CS, Stroud DA, Christodoulou J, Goranitis I. A micro-costing study of mass-spectrometry based quantitative proteomics testing applied to the diagnostic pipeline of mitochondrial and other rare disorders. Orphanet J Rare Dis. 2024 Nov 29;19(1):443. doi: 10.1186/s13023-024-03462-w. PMID: 39609890; PMCID: PMC11605922.