CD4 and agammaglobulinemia: Rare variants in other inborn error of immunity–related genes filtered by whole exome sequencing in P3 and P4 were listed as benign or variant of unknown significance on gnomAD/ClinVar and did not align with reported clinical features or zygosity reported by the International Union of Immunologic Societies.71 Both were adult patients with hypogammaglobulinemia, both sharing reduced naive CD4+ T cells with the LIG4 p.R580Q mutation carriers of the index family (Table E1).