Thyroid peroxidase gene polymorphisms and autoimmune thyroid disease

Thyroid peroxidase (TPO) as the key enzyme in thyroid hormones synthesis, expressed mainly in thyroid cells, and this enzyme considered as a major thyroid microsomal antigen; antibodies against TPO (anti-TPO) has been determined by assessing the antibodies directed against the thyroid gland. Anti-TPO is an important marker to diagnose the autoimmune thyroid diseases (AITDs) and also to estimate its clinical source. AITDs include the Graves’ disease (GD) and Hashimoto’sthyroiditis (HT); the annual incidence of GD worldwide is estimated to be 5cases per 10000 people, and this estimation isabout 3-5 per 10000 people for HT. Thyroid peroxidase gene is located on 2p25 and contains 17 exons. Published moleculargenetic studies suggested that TPO gene variations such as mutations and polymorphisms are one of the most commoncauses of thyroid dyshormonogenesis .The majority of TPO genetic variations localized in exon 8, 9, 10 and 11, which encode the catalytic site, and these variations may alter the structure of TPO protein, and leading to produce autoantibody against it. The results of studies in Iranian population confirmed that TPO gene polymorphisms could be associated with Anti-TPO levels and AITD. Conclusion Genetic and environmental factors which promote complex diseases such as AITD are largely unknown. According to studies, which assesse the role of genetic factors in autoimmune thyroid diseases, multiple-gene polymorphisms appear to be needed to develop the AITD and these factors may differ between geographic populations

کلیدواژه ها:

thyroid peroxidase ، autoimmune thyroid disease ، polymorphism