[Association of polymorphisms G1193/C exon 8 and C2145/T exon 12 with anti-TPO titer in Iranian population]

ABSTRACT

Autoimmune thyroid diseases [AITD] are common and it is important to identify the genetic determinants. 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. We selected 184 individuals from Tehran Lipid and Glucose Study, categorized as the Anti-TPO- [n=72] and Anti-TPO+ [n=112] groups. Inclusion criteria for cases was Anti-TPO and Anti-Tg>100U/L with a history of hypothyroidism. Anti-TPO levels in subjects were measured by the ELISA kit. Genomic DNA was extracted using Saltingout/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. The C allele frequency of C2145/T polymorphism Exon 12 [rs732608] was observed in 71.2% of patients and in 28.8% of normal individuals. This allele was significantly associated with increased levels of Anti-TPO [[T 140 +/- 330 pmol/L; vs. C 436 +/- 380 pmol/L; P<0.001], [OR 9.2]]. The G1193/C was not associated with the level of serum Anti-TPO in this study. We demonstrated that the C allele polymorphism in C2145/T exon 12 is associated with high levels of serum Anti-TPO and that carriers of this allele are predisposed to disease 9.2 times more than those who do not have A allele