Association of the thyroglobulin gene polymorphism with autoimmune thyroid disease in Chinese population

This study was performed to identify the presence of previously reported thyroglobulin (Tg) gene single nucleotide polymorphisms (SNPs) in Han Chinese Asians, and to investigate their potential relation to autoimmune thyroid disease (AITD).

Polymorphisms were determined by polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP) in 228 Chinese patients with AITD (146 with Graves' disease and 82 with Hashimoto's thyroiditis) and 131 healthy Chinese controls.

(1) The occurrence of four common Tg gene SNPs (E10SNP24 T/G and E10SNP158 T/C in exon 10, E12SNP A/G in exon 12, and E33SNP C/T in exon 33) was confirmed in this Chinese population. No differences in allele and genotype frequencies were found between AITD patients and control subjects, or between male and female individuals in any group. Neither were differences in allele frequencies observed when Graves' disease (GD) or Hashimoto's thyroiditis (HT) patients were analyzed separately. (2) Haplotype analysis of these four SNPs revealed that the G-C-A-C haplotype was significantly associated with HT (P < 0.01, OR = 3.06, OR 95% CI [1.326-7.089]) and with serum anti-Tg antibody (Tg-Ab) positive AITD patients (P = 0.028, OR = 3.34).

Our study confirms the existence of four SNPs among Han Chinese. In addition, the association of one SNP haplotype with HT suggests that Tg may be an AITD susceptibility gene.