Objective: To assess the association of thyroperoxidase (TPO) gene polymorphisms with dyshormonogenesis in congenital hypothyroidism (CH).
Methods: The 17 exons and flanking introns of the TPO gene from 30 randomly selected samples were sequenced for the selection of single nucleotide polymorphisms (SNPs). In 136 patients with dyshormonogenetic CH and 141 healthy controls from the same region, the selected SNPs were genotyped by polymerase chain reaction (PCR) and direct sequencing or PCR-restriction fragment length polymorphism (RFLP).
Results: Six SNPs (rs9678281, rs376413622, rs1126797, rs4927611, rs732609 and rs1126799) were selected to determine the genotype for each sample. Among these, rs4927611 and rs732609 showed a significant difference between the two groups in both allelic and genotypic frequencies. With a recessive model of inheritance, rs732609 CC (OR=0.484, 95%CI: 0.253-0.927, P=0.04) and rs4927611 TT (OR=0.32, 95%CI: 0.112-0.915, P=0.047) were greater in the patients.
Conclusion: rs4927611 and rs732609 may be associated with dyshormonogenetic CH. rs4927611 TT and rs732609 CC are genotypes associated with potential risk for the disease.