Primary immunodeficiencies (PID) [381 genes]

Primary immunodeficiency diseases (PID) comprise a heterogeneous group of more than 300 distinct hereditary disorders, each of them caused by a different gene defect. Our panel includes those genes that have been associated with a defective adaptive or innate immune response, either by causing a specific or combined B or T cell deficiency, a particular defect of phagocytes or host defences, or a deficiency of the complement system. Clinical manifestations are highly variable; however, most affected individuals share an increased vulnerability and susceptibility to infections affecting various body systems. The estimated prevalence of PID is about 1 in 1,200 births. The complexity and symptom overlap found in PID makes genetic testing essential for the understanding and diagnosis of the disease and a better management of the patient.

Currently, it is estimated that primary immunodeficiencies have a prevalence of 1-5/5,000.

Identifying a genetic defect responsible for the disease would allow a precise molecular diagnosis to be issued and make it possible to provide genetic counseling to the patient and their family members. In some cases, detecting a genetic variant can help explore specific treatment options.

Primary immunodeficiencies should be suspected when there is a high predisposition to moderate and severe infections. The presence of autoimmunity, autoinflammation, and hypersensitivity reactions, isolated or concurrent, are also typical manifestations of primary immunodeficiencies. Usually, these disorders manifest themselves at an early age, but they can be more evident in adulthood, so their expression affects all age groups.

Depending on the group of diseases, the yield of the genetic study varies between 10%-25%. Primary immunodeficiencies that affect adaptive immunity are those with the highest diagnostic yield.