ZAP70 deficiency
Other names	ZAP70 deficient SCID
ZAP70 deficiency has an autosomal recessive pattern of inheritance.

ZAP70 deficiency, or ZAP70 deficient SCID,^[1] is a rare autosomal recessive form of severe combined immunodeficiency (SCID) resulting in a lack of CD8+ T cells.^[2] People with this disease lack the capability to fight infections, and it is fatal if untreated.

It is cause by a mutation in the ZAP70 gene.

Presentation

Children with this condition typically present with infections and skin rashes.^[3] Unlike many forms of SCID, absolute lymphocyte count is normal and thymus is present.^{[citation needed]}

Cause

ZAP70 deficiency SCID is caused by a mutation is the ZAP70 gene, which is involved in the development of T cells.^[3]

Diagnosis

It is characterized by a lack of CD8+ T cells and the presence of circulating CD4+ T cells which are unresponsive to T-cell receptor (TCR)-mediated stimuli.^[4] Diagnosis is usually made within the first six months of life. Genetic testing is required.^[3]

Treatment

Hematopoietic stem cell transplantation is the only known cure for ZAP70 deficient SCID.^[5]

Epidemiology

ZAP70 deficiency SCID is estimated to occur in approximately 1 in 50,000 people. Fewer than fifty people with this condition have been identified.^[3]