ZAP70 deficiency
ZAP70-related severe combined immunodeficiency (ZAP70-related SCID) is a cell-mediated immunodeficiency caused by abnormal T-cell receptor (TCR) signaling. Affected children usually present in the first year of life with recurrent bacterial, viral, and opportunistic infections, diarrhea, and failure to thrive. Severe lower respiratory infections and oral moniliasis are common. Affected children usually do not survive past their second year without hematopoietic stem cell transplantation (HSCT)