Researchers from the University of Western Australia have created a genetic test, including a panel of 120 genes, to help diagnose primary immunodeficiency disorders (PIDs).
The scientists trialed the test in a group of 22 individuals with symptoms of having a PID, but no clear diagnosis and genetic variants indicative of disease diagnosis were uncovered in a third of the group.
There are more than 450 known PIDs, but accurate and early diagnosis for those affected has historically been difficult.
“Despite major advances in the molecular and genetic characterization of PIDs over the last 20 years, timely and accurate diagnosis of PID remains a challenge. This is particularly evident for the more common types of PID, such as common variable immunodeficiency (CVID), where there is a wide spectrum of clinical manifestations and late onset of symptoms,” write the authors in the Journal of Molecular Diagnostics.
The 22 individuals who took part in the study met the European Society for Immunodeficiencies/Pan-American Group for Immunodeficiency diagnostic criteria for CVID, which is the most common type of PID, impacting around 1 in 25,000 people. They did not have a prior genetic diagnosis.
The team looked for variants that could be pathogenic in 120 genes previously linked to immune function. Overall, 130 genetic variants were detected in the group and examined further using next generation sequencing.
Variants defined as pathogenic, or likely pathogenic, were found in 6 of the 22 individuals tested in the genes: ICOS, TNFRSF13B, TNFRSF13C, and AICDA. Variants of unknown significance, which could also be pathogenic, were also observed in 4 additional participants in the genes: IL21R, ICOS, NFKB2, and CD40LG.
Identification of the genetic variant causing CVID can be helpful for patients and healthcare providers, as it can help direct treatment better and give patients a better idea of prognosis of their condition. It can also help prospective parents who are carriers of these variants to make decisions about having a family.
“Recent advances in genetic technology allow affordable testing of multiple genes from the same individual. We can therefore identify a specific gene that may lead to frequent infections in patients. An earlier and more accurate diagnosis may improve the patient outcome and prevent complications,” explained Lloyd D’Orsogna, a senior lecturer at the University of Western Australia in Perth, in a press statement.
“I hope the new age of genetic medicine enables earlier and more accurate diagnosis, likely leading to better treatment and outcomes for all.”