Detection of CTLA- 4 and PTPN22 Genes Polymorphisms and Relationship with Hyperthyroidism Patients in Thi-Qar Province�, Iraq.

Abstract

Rasha Salih Nuhair, Nabeel Mahdi Abid, Shaymaa Z.Al-Rumaidh

This study was conducted to identify the genetic polymorphisms of the cytotoxic T-lymphocyte-associated protein 4 (CTLA4) gene and protein tyrosine phosphatase non-receptor 22 (PTPN22) gene to investigate the possible association of their polymorphism with the development or progression of hyperthyroidism. Two genetic loci covering two regions within the CTLA4 and PTPN22 genes were amplified by PCR. Next, a direct sequencing strategy was performed for the observed PCR amplicons to assess the pattern of genetic polymorphism in the screened specimens. Subsequently, the observed variants were localized according to their positions within the referring genomic DNA sequences. The results indicated a significant increase (P<0.05) in thyroxin(T4) and triiodothyronine (T3) hormones while no significant changes of thyroid stimulating hormone (TSH) compared with health group. In addation , Our results indicated the presence of only one single nucleotide polymorphism (SNP) in the CTLA4 gene that was only localized in only one investigated patient sample compared with the normal referring sequences. This novel SNP, A81G, was observed in one samples, while no other SNP was detected in other samples . However, no variation was detected in all investigated samples concerning the investigated PTPN22 gene. In conclusion, the present study detected a novel A81G SNP within the targeted CTLA4 gene which may be associated with the progression of hyperthyroidism. Further large-scale screening studied is highly recommended to provide a more comprehensive view of this crucial genetic locus in Iraqi populations.