TNFRSF13B and immunodeficiency, common variable, 2: Whole-exome sequencing identified a maternally inherited heterozygous frameshift variant in TNFRSF13B (c.105del, p. Glu36LysfsTer48; MAF0.0000544), classified as likely pathogenic and consistent with an immunoglobulin A deficiency type 2 and common variable immunodeficiency type 2 phenotype.