GATA2 and infectious mononucleosis: Identical twins with GATA2 insufficiency, due to a stop codon (R330X) in one allele, presented with symptoms of infectious mononucleosis; one had three hospitalizations for anorexia and dehydration accompanied by anemia, fatigue, weight loss, and fever for 3 months with 20,600 copies of EBV DNA/ml of blood (29).