Estrogen receptor alpha dinucleotide repeat polymorphism in Japanese patients with autoimmune thyroid diseases

BACKGROUND: The autoimmune thyroid diseases (AITDs), comprising Graves' disease (GD) and Hashimoto's thyroiditis (HT), appear to develop as a result of complex interactions between predisposing genes and environmental triggers. Susceptibility to AITDs is conferred by genes in the human leukocyte antigen (HLA) and genes unlinked to HLA, including the CTLA-4 gene. Recently, an association to some estrogen receptor (ER)α genotypes with breast cancer, hypertension, osteoporosis, generalized osteoarthritis, and some autoimmune diseases such as rheumatoid arthritis has been reported. We have analyzed a dinucleotide (TA)n repeat polymorphism lying upstream of the human ERα gene in patients with AITDs and in normal subjects. RESULTS: Seventeen different alleles were found in 130 patients with GD, 93 patients with HT, and 190 control subjects. There was no significant difference in the distributions of ERα alleles between patients and controls. CONCLUSIONS: The present results do not support an association between the ERα gene and AITD in the Japanese population.