Abstract
Zeta associated protein (ZAP) 70 deficiency is a rare disease. ZAP70 deficiency results in an autosomal recessive form of severe combined immunodeficiency (SCID) that is characterized by a selective absence of CD8 T cells. The diagnosis should be suspected in patients presenting with a severe combined immunodeficiency phenotype and selective deficiency of CD8 T cells. Sequencing of the ZAP70 gene can confirm the diagnosis. We wanted to emphasize that immunodeficiencies should also be remembered in the differential diagnosis by presenting a 5-month-old patient who applied to our clinic with complaints of skin rash and cough, was given respiratory support with mechanical ventilation for a long time, and was diagnosed with ZAP70 deficiency.