In primarily antibody deficiencies, BTK mutations (e.g., c.1483G>A) were frequently identified in Bruton’s agammaglobulinemia, whereas CVID instances displayed various variants like c.310T>C (p.Cys104Arg) in TNFRSF13B, commonly regarded as variants of uncertain significance. This evidence concerns the gene TNFRSF13B and agammaglobulinemia.