Additional laboratory features that heighten suspicion include myelodysplasia marked by anemia and thrombocytopenia, lymphopenia with B‐lymphocytopenia, hypogammaglobulinemia, or impairment of isotype classification switching, with elevated IgM and absent or low IgA and IgG [1, 7]. The gene discussed is CD40LG; the disease is anemia (phenotype).