P9.1 and P9.2 (NFKB1 p.S302Ffs*7) both suffered autoimmunehaemolytic anaemia, which is reported in NFKB1 haploinsufficient patients.24, 25 Differing AI/I is observed in patients with NKFB1 mutations, ranging from antibody deficiency, Behcet-like disease, to an autoinflammatory phenotype.26 The gene discussed is NFKB1; the disease is agammaglobulinemia.