ZAP-70 (zeta-associated protein 70) deficiency is an immunodeficiency involving impaired T-cell activation caused by a signaling defect. It is a primary immunodeficiency disorder that involves cellular immunity deficiencies. Inheritance is autosomal recessive. ZAP-70 is important in T-cell signaling and in T-cell selection in the thymus. This deficiency causes T-cell activation defects.
They generally present during infancy or early childhood with recurrent infections similar to those in severe combined immunodeficiency (SCID); however, they live longer, and the deficiency may not be diagnosed until they are several years old.
Blood Testing necessary includes Complete blood count, including absolute WBC count and differential, is done; immunoglobulin levels are measured. Responses to mitogens and to standard vaccine antigens are determined to evaluate WBC and antibody function.
Patients have normal, low, or elevated serum immunoglobulin levels and normal or elevated numbers of circulating CD4 T cells but essentially no CD8 T cells.
Treatment of ZAP-70 deficiency generally involves preventing infection, managing acute infection, and replacing missing immune globulins.
The ZAP-70 deficiency is fatal unless treated by hematopoietic stem cell transplantation.