Therefore, because of its retrospective nature, a limitation in our study is that we lacked information about the consumption of drugs or supplements that may interfere with various steps of thyroid hormone metabolism that may increase the risk for hypothyroidism, including a history of previous surgery or radiation therapy on the thyroid gland or head and neck area, the presence of anti-thyroglobulin antibodies, and secondary or tertiary hypo/hyperthyroidism causes. The gene discussed is TG; the disease is hypothyroidism.