Direct haplotyping of bi-allelic SNPs using ARMS and RFLP analysis techniques

Matrix Gla protein (MGP) promoter polymorphic variants and its serum level in stenosis of coronary artery

Although the role of matrix Gla protein (MGP) is not completely known but, its expression within subendothelial macrophages and vascular smooth muscle cells is suggested to be involved in vascular calcification. In this study, we investigated the associations between the serum MGP levels and the MGP promoter high minor allele frequency (MAF) variants with the development of stenosis in coronary arteries. Moreover, we evaluated the allele changes within predicted transcription factor elements with bioinformatics tools. 182 subjects were recruited from who underwent coronary angiography. The MGP promoter rs1800801, rs1800802 and rs1800799 genotypes and haplotypes were detected by ARMS-RFLP PCR techniques. The serum MGP concentration was measured using ELISA method. Jaspar profiles were used for scoring the polymorphic variations within the transcription factor elements. The genotype and two-allelic haplotype distributions were not significant between the patient and control groups (P > 0.05). The serum MGP levels had not significant differences between the genotypes (P > 0.1) and haplotypes (P > 0.4). Based on the prediction studies, we did not observe significant differences between the polymorphic scores in the predicted elements (P > 0.05). We concluded that the genotype and haplotype distributions of the MGP promoter high-MAF polymorphisms, as confirmed in the prediction studies and the serum MGP level are not significantly associated with the coronary artery disease. Based on the study results, the MGP protein did not play an important role in the development of stenosis of coronary arteries.

No association between MGP rs1800802 polymorphism and stenosis of the coronary artery

BACKGROUND AND OBJECTIVES

Matrix Gla protein (MGP) was originally isolated from bone but it is known to be expressed in several tissues including kidney, lung, heart, cartilage and vascular smooth muscle cells (VSMC) of the blood vessel wall. Since it inhibits calcification in subendothelial space of vessels thus, we evaluated the association of rs1800802(T > C) polymorphism and stenosis of the coronary artery.

DESIGN AND SETTING

Cross-sectional case-control.

SUBJECTS AND METHODS

One hundred eighty two subjects recruited on the basis of study protocol from who underwent coronary angiography. The controls (n=70) had normal coronary arteries (up to 5% stenosis). The patients (n=112) subdivided into three subgroups; single-vessel disease (SVD), two-vessel disease (2VD) and three-vessel disease (3VD) based on the number of stenosed coronary vessels (at least 50% stenosis). rs1800802 (T > C) polymorphism was determined by PCR-RFLP technique.

RESULTS

Genotype distribution was not significant between control and patient groups. In addition, there were no significant differences between rs1800802 (T > C) frequency and gender (P=.092), and also patient subgroups (one-, two- and three vessel disease) (P=.840).

CONCLUSION

We concluded that rs1800802 (T > C) polymorphism within the MGP promoter is not related to stenosis of the coronary artery.

Association between rs4673 (C/T) and rs13306294 (A/G) haplotypes of NAD(P)H oxidase p22phox gene and severity of stenosis in coronary arteries

Phagocytic NADH/NADPH oxidase is an important enzyme producing reactive oxygen species within subendothelial space of vessels. Findings have shown that p22phox subunit is an essential element related to the enzyme activity. Since some p22phox polymorphisms are thought to have functional roles in the enzyme thus, we studied the association between rs4673 (C242T) and rs13306294 (A/G) haplotypes and the severity of stenosis in coronary arteries. One hundred eighty-two subjects undergoing coronary angiography were recruited on the base of study design. Patients (n=114) had at least a stenosed coronary artery (>50% stenosis) and subdivided into three subgroups; SVD (n=28), 2VD (n=31) and 3VD (n=55) while controls (n=68) had the normal coronary arteries (<5% stenosis). The direct haplotyping technique of SNPs was performed using ARMS-RFLP-PCR method. Furthermore, alphabet-based tools predicted the changes of secondary structure at the rs4673 position. All haplotypes being proposed theoretically were found in the study population. The distribution of two-allele haplotypes had no significant difference between patients and controls (P=0.1). Although the rs4673 allele frequency was not significant between the groups (P>0.5), chi square test and multinomial regression analysis showed an observed high risk for rs13306294 A allele among patients. The bioinformatics tools predicted that the p22phox secondary structure is not changed due to the substitution of Tyr→His at the rs4673 position. We concluded that the polymorphisms have no allele linkage on the chromosome. In addition, the rs13306294 A allele is a potential factor of stenosis of coronary arteries that increases susceptibility for the extent of disease.