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

OBJECTIVE: 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). METHODS: 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. RESULTS: (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). CONCLUSION: 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.

[Association of polymorphism of protein tyrosine phosphatase nonreceptor-22 gene with AITD].

AIM: To evaluate the association of PTPN22 gene polymorphism with autoimmune thyroid disease (AITD) in Chinese people and to analyze the relationship between SNP of CTLA-4 gene and SNP of PTPN22 gene. METHODS: 149 patients with Graves' disease (GD) and 82 patients with Hashimoto's thyroiditis (HT) as well as 131 healthy people as controls were investigated. PTPN22 gene polymorphism +1858 C>T and CTLA-4 gene polymorphism 49A>G were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). PTPN22 gene polymorphism -1123G>C at promoter was genotyped by single allele-specific primer polymerase chain reaction (SASP-PCR). RESULTS: (1) +1858C>T for PTPN22 gene was not polymorphic enough in patients and controls. (2) Statistic differences in alleles and genotype frequency of -1123G>C were observed between GD patients and controls (P=0.040, 0.013; OR=1.44, 2.33, respectively). (3) Differences in alleles and genotype frequency of 49A>G for CTLA-4 gene were observed in patients and controls. (4) Individuals with PTPN22 CC genotype and CTILA-4 G alleles had an increased risk of developing GD (OR=3.31, 95%CI: 2.69-8.89) compared with those with PTPN22 G alleles and CTLA-4 AA genotype. CONCLUSION: -1123 G>C SNP of PTPN22 gene is associated with GD. There is coordination between PTPN22 CC genotype and CTLA-4 G alleles in the development of GD.