DUOX2 (OMIM: 606759), TG (OMIM: 188450), and TPO (OMIM: 606765) are the genes most frequently implicated in cases of TDH; however, other genes have also been included in the “Congenital Hypothyroidism: A 2020–2021 Consensus Guidelines Update” as genes associated with TDH, such as DUOX1, DUOXA2, SLC5A5 (NIS), SLC26A4 (PDS), SLC26A7, IYD (DEHAL1), GNAS, and TSHR (OMIM: 603372) (16). This evidence concerns the gene IYD and hypothyroidism.