OLR1 Gene Polymorphism and Oxidized LDL Levels in Metabolic Syndrome in Indian Population

OBJECTIVE

Metabolic syndrome (MetS) is associated with abnormal lipid profile and high cardiovascular risk. There is an increased prevalence of coronary artery disease and Type 2 Diabetes Mellitus in India. Oxidized Low Density Lipoprotein Receptor 1(OLR1), a cell surface endocytosis receptor recognize, internalize and degrade oxidized LDL (oxLDL) in vascular endothelium and plays a role in the pathogenesis of atherosclerosis. The aim was to explore the association of OLR1 gene polymorphism and measure the serum levels of ox-LDL in patients with MetS in Indian population.

MATERIALS AND METHODS

Forty cases fulfilling the IDF diagnostic criteria for MetS and 40 healthy controls having similar age and sex ratio were genotyped for OLR1 gene (SNP: IVS4-73C>T , rs3736234) by RFLP-PCR. Serum ox-LDL was estimated by ELISA.Their BP, BMI and waist circumference were measured. Fasting Plasma glucose, Serum Triglyceride and HDL-C were measured.

RESULTS

Serum oxLDL was significantly higher in MetS cases as compared to controls (p < 0.0001). Odds ratio of T allele of above OLR1 SNP among subjects with MetS was 14.79 (95%CI: 1.80-121.2, p < 0.05). But no association was found between the SNP and serum ox-LDL levels. People having TT allele had higher BMI compared to those having CC allele.

CONCLUSION

Ox LDL, being more atherogenic might contribute in the pathogenesis of MetS. The intronic SNP: IVS4-73 C>T of OLR1 gene increases the risk of developing MetS by a yet unknown mechanism that is independent of rise in ox-LDL. This OLR1 SNP probably influences BMI.

Phenylalanine hydroxylase deficiency in the Slovak population: genotype-phenotype correlations and genotype-based predictions of BH4-responsiveness

We investigated the mutation spectrum of the phenylalanine hydroxylase gene (PAH) in a cohort of patients from 135 Slovak PKU families. Mutational screening of the known coding region, including conventional intron splice sites, was performed using high-resolution melting analysis, with subsequent sequencing analysis of the samples showing deviated melting profiles compared to control samples. The PAH gene was also screened for deletions and duplications using MLPA analysis. Forty-eight different disease causing mutations were identified in our patient group, including 30 missense, 8 splicing, 7 nonsense, 2 large deletions and 1 small deletion with frameshift; giving a detection rate of 97.6%. The most prevalent mutation was the p.R408W, occurring in 47% of all alleles, which concurs with results from neighboring and other Slavic countries. Other frequent mutations were: p.R158Q (5.3%), IVS12+1G>A (5.3%), p.R252W (5.1%), p.R261Q (3.9%) and p.A403V (3.6%). We also identified three novel missense mutations: p.F233I, p.R270I, p.F331S and one novel variant: c.-30A>T in the proximal part of the PAH gene promoter. A spectrum of 84 different genotypes was observed and a genotype based predictions of BH4-responsiveness were assessed. Among all genotypes, 36 were predicted to be BH4-responsive represented by 51 PKU families. In addition, genotype-phenotype correlations were performed.