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). Here, SLC5A5 is linked to cyclic hematopoiesis.