In F6, two siblings (a, b) with CH were both homozygous for TG p.W1051L and p.C726Y but one sibling (F6b) harbored an additional, maternally inherited heterozygous DUOX2 mutation (p.Q686*), previously described in association with transient CH (21). The gene discussed is DUOX2; the disease is cyclic hematopoiesis.