Of the 33 LT3S patients, 6 patients were with concomitant low TSH concentrations, thereby indicating changes in the hypothalamic-pituitary regulation; 1 patient was with concomitant low FT4 concentration, which may also be due to an impaired hypothalamic or pituitary regulation.22 Despite these changes, serum concentrations of anti-TG Ab, anti-TPO Ab, anti-TM Ab, and anti-TR Ab were normal in all patients enrolled in our study, which conformed there was no autoimmune thyroid disease in all the 39 individuals. This evidence concerns the gene TPO and autoimmune thyroid disease.