Thyroid autoimmunity (TAI) is defined as the presence of antithyroid antibodies – anti-thyroid peroxidase (TPO-Ab) and/or anti-thyroglobulin (TG-Ab) antibodies – and is the most common autoimmune condition in women of reproductive age, with a prevalence of 8–14% [1, 2]. This evidence concerns the gene TPO and Autoimmunity.