Although the patient survived beyond infancy, he fulfilled the SCID diagnostic criteria according to the Primary Immune Deficiency Treatment Consortium (PIDTC) criteria definition, based on the presence of a confirmed pathogenic ZAP70 variant, severely reduced CD4+ and CD8+ counts (<300 cells/μL), and a clinical history of recurrent infections and growth failure[8]. The gene discussed is CD4; the disease is Immunodeficiency.