Many genes associated with CH and GIS have been described in the literature: defects in iodine uptake by thyrocytes (NIS/SLC5A5 mutations), partial or total iodine organification defects (P/TIOD) (mutations in the TPO, DUOX2, DUOXA2, and PENDRIN (SLC26A4) genes), defects in the synthesis, storage, or release of TG, or IYD defects (DEHAL1) (57). The gene discussed is DUOX2; the disease is cyclic hematopoiesis.