Genetics of Autoimmune Thyroid Diseases in Asians

Autoimmune thyroid diseases (AITDs), including Graves’ disease (GD) and Hashimoto’s thyroiditis (HT), are among the commonest autoimmune disorders, affecting approximately 2-5 % of the population. Epidemiological data support strong genetic influences on the development of AITD. The identification of genes placing individuals at an increased risk for the development of AITD has been a slow process. However, over the last 20 years real progress has been made with the mapping of novel loci, via a number of different approaches. The first AITD gene discovered, Human Leucocyte Antigen (HLA)/Major Histocompatibility Complex (MHC), is associated with both GD and HT. Non-MHC genes that confer susceptibility to AITD can be classified into two groups: (1) immune-regulatory genes (e.g: CD40, CTLA-4, and PTPN22); (2) thyroidspecific genes—thyroglobulin and TSH receptor genes. These genes interact with environmental factors, such as infection, likely through epigenetic mechanisms to trigger disease. In this review, we will summarize the latest findings on AITD susceptibility genes in Asians in comparison with Caucasians.