Association between serum level of anti-TPO titer and polymorphisms G1193/C Exon 8 and C2145/T Exon 12 of thyroid peroxidase gene in an Iranian population

Background: autoimmune thyroid diseases (aitd) are common, with important epidemiological data, including family and twin studies, supporting a strong genetic background on the etiology of aitd.objectives: the aim of this study was to assess the relationship between two polymorphisms of thyroid peroxidase gene (tpo) and serum level of anti-tpo titer in an iranian population.patients and methods: a sample of 184 participants from the tehran lipid and glucose study was selected as the case (no.=112) and control (no.=72) groups. inclusion criteria for cases were anti-tpo and anti-tg>100u/l with a history of hypothyroidism. anti-tpo level in subjects was measured by the elisa kit. genomic dna was extracted using salting-out/proteinase k method. polymorphism detection of exon 8 and 12 was done using the pcr-rflp method. the pcr products were incubated with restriction enzymes sacii and bsri, respectively.results: the c allele frequency of c2145/t polymorphism exon 12 (rs732608) was observed in 71.2% of patients and 28.8% of normal individuals. this allele was significantly associated with increased levels of anti-tpo [(tt, 140±330 pmol/l; vs. cc, 436±380 pmol/l; p < 0.001), (or: 9.2)]. the g1193/c was not polymorphic and no association between this snp and the level of serum anti-tpo was found in this study.conclusions: we found that the c allele polymorphism in c2145/t exon 12 is associated with the high level of serum anti-tpo and that carriers of this allele are predisposed to disease 9.2 times more than those, who have no c allele. the selected polymorphism of exon 8 has no effect on increased levels of anti-tpo.