High resolution melting analysis to genotype the most common variants in the HFE gene.

BACKGROUND: High resolution melting (HRM) analysis of PCR amplicons was recently introduced as a closed-tube, rapid, and inexpensive method of genotyping. This study evaluated this system as an option for detecting the three most common mutations in the HFE gene (C282Y, H63D, S65C), accounting for the main form of hereditary haemochromatosis. METHODS: Ninety samples, previously screened by direct sequencing, and 27 controls were used. The analysis were performed on the Rotor Gene Q, using the commercial HRM mix containing the Eva Green dye (Qiagen). Specific primers allowed the amplification of the regions of interest in the HFE gene. Following amplification, a HRM analysis was conducted to detect DNA variants. The thermal denaturation profiles of the samples were compared with those of the controls. RESULTS: One hundred percent of heterozygous and homozygous samples were readily identified. Heterozygotes were easily identified because heteroduplexes altered the shape of the melting curves, but significant differences were also present in the melting curves of the homozygous carries compared with those of the wild-type subjects. CONCLUSIONS: HRM analysis is an appealing technology for HFE gene screening. It is a robust technique that can be widely adopted in diagnostic laboratories to facilitate gene mutation screening.

Sexual dysfunction is frequent in premenopausal women with diabetes, obesity, and hypothyroidism, and correlates with markers of increased cardiovascular risk. A preliminary report.

INTRODUCTION: Female sexual dysfunction (FSD) is characterized by reduced sexual appetite and altered psychologic and physiologic response to sexual intercourse; it is reported to be frequent in diabetes mellitus, but no data have been reported in thyroid disorders. AIMS: To compare the prevalence of FSD in diabetic, in obese, and in hypothyroid women vs. healthy women, and to correlate FSD with endocrine and metabolic profiles. METHODS: We evaluated, through a questionnaire (Female Sexual Function Index [FSFI]), the prevalence of FSD in 91 women affected by diabetes mellitus, obesity, or hypothyroidism, and in 36 healthy women, all aged 22-51 years and in premenopausal state. MAIN OUTCOME MEASURES: FSFI score, endocrine and metabolic parameters (triglycerides, high-density lipoprotein [HDL] and low-density lipoprotein [LDL] cholesterol, free-triiodothyronine (FT3), free-thyroxine (FT4), thyroid stimulating hormone [TSH], 17-beta-estradiol, testosterone, glycated hemoglobin 1c (HbA1c), thyroid autoantibodies, E-selectin, P-selectin, intercellular adhesion molecule-1 [ICAM-1], plasminogen-activator inhibitor-1 [PAI-1]), and anthropometric parameters (body mass index, waist, blood pressure [BP]). RESULTS: A reduced FSFI score was more frequent in diabetic, obese, and hypothyroid women vs. healthy women (P < 0.01). In the different groups of women, FSFI score was inversely correlated (pairwise correlation) with at least one of the following: HbA1c, TSH, LDL-cholesterol, PAI-1, diastolic BP, presence of thyroid Ab, and directly correlated with HDL-cholesterol (always P < 0.05 or less). At stepwise regression analysis, HDL-cholesterol (protective) and HbA1c, LDL-cholesterol, PAI-1, and diastolic BP (negatively) predicted reduced FSFI score. CONCLUSION: These data indicate an increased prevalence of sexual dysfunction in diabetic, in obese, and in hypothyroid women, associated with markers of cardiovascular risk.

Matrix metalloproteinase-1 and matrix metalloproteinase-3 gene promoter polymorphisms are associated with mortality in haemodialysis patients.

BACKGROUND: Vascular calcification and accelerated atherosclerosis are major causes of death in haemodialysis (HD) patients. Matrix metalloproteinases (MMPs) are a family of enzymes, involved in the biology of extracellular matrix and in atherogenesis. MMP1 and MMP3 contribute to the enlargement and instability of atherosclerotic plaque, respectively. The common polymorphisms on MMP1 (2G/2G) and MMP3 (6A/6A) gene promoters have been related to increased coronary artery calcification and to carotid artery stenosis. The aim of this study was to evaluate the association of MMP1 and MMP3 polymorphisms with end-stage renal failure (ESRD) and all-cause mortality risk in HD. METHODS: Ninety-nine HD patients, followed-up for 36 months, and 133 matched controls were genotyped for the two polymorphisms. HD patients' characteristics were age 64 +/- 13 years, males 64%, diabetic 24%, hypertensive 62%, smokers 38%, dyslipidaemic 28%, all undergoing standard HD thrice weekly. RESULTS: ESRD was strongly associated with the combination of 2G/2G and 6A/6A homozygosity: OR 2.57 (0.95-7.4), P = 0.037, but not with isolated 2G/2G and 6A/6A homozygosity (P = 0.09 and P = 0.11, respectively). Isolated 2G/2G was associated with all-cause mortality risk independently from age, gender, diabetes, hypertension, smoking, dyslipidaemia, C-reactive protein, albumin, dialysis vintage and history of cardio-vascular disease: HR 2.96 (1.29-6.80), P = 0.01. A trend for the association of mortality and isolated 6A/6A homozygosity was also observed: HR 3.01 (0.88-10.26), P = 0.078. Combination of 2G/2G and 6A/6A homozygosity significantly increased the mortality risk in the same Cox regression model: HR 4.69 (1.72-12.81), P = 0.003. CONCLUSIONS: In this study, we demonstrated for the first time that MMP-1 and MMP-3 gene polymorphisms are negative prognostic risk factors for all-cause mortality in HD patients, independently from traditional risk factors. These data may have important implications for better understanding the pathogenesis of the increased mortality in HD patients.

Genetic control of chemokines in severe human internal carotid artery stenosis.

BACKGROUND AND PURPOSE: Atherosclerosis is an inflammatory disease. Chemokines and chemokine receptors are known to be involved in atherogenesis. Common single nucleotide polymorphisms (SNPs) affect transcription in response to inflammatory stimuli. The aim of this study was to evaluate the correlations between MCP-1, RANTES, SDF-1, CCR2, and CCR5 gene polymorphisms with increased risk of internal carotid artery (ICA) stenosis. METHODS: Hundred and twelve patients, consecutively recruited for ICA occlusive disease, and 282 controls were genotyped for MCP-1-2518G, RANTES-403A, CCR5Delta32, CCR2 V64I, and SDF-1-801A polymorphisms. RESULTS: The frequency of the SDF-1A allele was significantly different between cases and controls: 0.32 vs. 0.20, respectively (OR 1.81; 95% CI 1.25-2.60; p=0.007). The frequency of the RANTES-403G allele was significantly higher in patients with stenosis >70% (OR, 2.45; 95% CI 1.12-5.71; p=0.015). No significant differences were observed with the other polymorphisms. CONCLUSION: The reported results seem to correlate the polymorphisms of the genes encoding for SDF-1, RANTES with pathogenesis and progression of ICA occlusive disease. Although suggestive, these results need confirmation in prospective cross-sectional studies.

Serum fetuin-A levels link inflammation and cardiovascular calcification in hemodialysis patients.

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of mortality in hemodialysis (HD). An elevated incidence of cardiovascular calcifications (CVC) is observed in HD. Fetuin-A is an important inhibitor of CVC. Reduced fetuin-A levels associate with inflammation and increased cardiovascular (CV) mortality in HD. In this study we investigated the association of fetuin-A levels and CVC. METHOD: We evaluated a cohort of 115 patients (67 males), aged 63 +/- 16 years with a HD vintage >or=9 months. Presence of CVC was assessed by ultrasound imaging of the abdominal aorta, common carotid arteries, bilateral ilio-femoral axis, aortic and mitral cardiac valves. The presence of CVC was analyzed as a CVC score (CVCS) (0-7) according to the number of CVC sites. Patients were arbitrary stratified in three groups: group I (CVCS = 0), group II (0 < CVCS < 6) and group III (CVCS >or= 6). Patients without CVC were younger, non-diabetic and with a negative history for CV events. RESULTS: Patients with evidence of CVC in more than 5 sites had lower serum fetuin-A levels (0.41 +/- 0.22 g/l) compared to patients with CVCS = 0 (0.51 +/- 0.17 g/l, p = 0.048). In addition a worse CVCS was associated with higher serum levels of C-reactive protein (p = 0.002) and fibrinogen (p < 0.001). Serum fetuin-A levels lower than 0.290 g/l were associated with higher risk of a worse CVCS, independently from traditional risk factors. CONCLUSION: Chronic inflammation in HD patients leads to lower serum fetuin-A levels. The present study confirms the independent and significant association between reduced serum fetuin-A levels and multi-site CVC in HD.

Matrix GLA protein gene polymorphisms: clinical correlates and cardiovascular mortality in chronic kidney disease patients.

BACKGROUND: Increased vascular calcification plays an important role in the pathogenesis of cardiovascular events in chronic kidney disease (CKD) patients. It is the result of an active ossification process counteracted by 'protective' proteins, such as matrix GLA protein (MGP). Polymorphisms of MGP have been identified. METHODS: The aim of this study was to define the distribution of two MGP polymorphisms (-7, -138) in 99 hemodialysis (HD) patients, in 26 patients with CKD stage 3 and in 135 age- and sex-matched healthy controls. Patients were followed up for 12 months to record any cardiovascular deaths. The cause of death was determined by medical doctors, considering the medical history of each patient. The primers were designed with Primer Express software. RESULTS: MGP -138TT homozygotes were more frequent in the HD group versus controls (p = 0.0004). Additionally, the frequency of the T allele was significantly higher in the HD group (p = 0.0006). The frequency of the A allele of MGP-7 was significantly higher both in the HD group (p = 0.033) and in the CKD group (p = 0.0017) versus controls. MGP-7 GG homozygotes were significantly less common in the CKD group than in controls (p = 0.037). Combination -138TT -7AA was significantly more frequent in both CKD patients (p = 0.001) and in HD patients (p = 0.029) than in controls. Seventeen out of 99 HD patients experienced fatal cardiovascular events. Sixteen (94.1%) were -138TT homozygotes and either -7AA homozygotes or -7GA heterozygotes. CONCLUSION: This study suggests that CKD and HD patients have a different distribution of MGP gene polymorphism as compared with the normal population. Altered MGP gene polymorphism may be a negative prognostic factor for the progression to end-stage renal disease and for cardiovascular events in CKD patients.

Internal carotid artery occlusive disease and polymorphisms of fractalkine receptor CX3CR1: a genetic risk factor.

BACKGROUND AND PURPOSE: Fractalkine (FKN), a chemokine expressed by inflamed endothelium, induces leukocyte adhesion and migration via the receptor CX3CR1. The polymorphisms V249I and T280M affect receptor expression and function. The role of FKN in atherosclerosis has been recently demonstrated. The aim of this study was to investigate a possible association between CX3CR1 polymorphisms and increased risk of internal carotid artery (ICA) occlusive disease. METHODS: We studied 108 patients consecutively recruited for ICA occlusive disease, 84 of whom underwent operation for carotid endarterectomy, and 204 subjects without ICA occlusive disease (controls). Polymorphic genotypes were determined by polymerase chain reaction and sequencing analysis. RESULTS: The adjusted odds ratio (OR) associated with the presence of the M280 (TM+MM versus TT genotype) was 0.55 (95% CI: 0.29 to 0.99; P=0.037). Therefore, this allele is associated with a reduced risk of ICA occlusive disease. No significant differences were observed in I249 distribution. The frequency of I249 allele was significantly higher in cases of hard plaques, which are considered more stable than soft ones (OR: 0.38; 95% CI: 0.13 to 1.05; P=0.037). Multiple logistic regression analysis using the common risk factors and the I249 and M280 allele variants revealed that the M280 allele was an independent risk factor for ICA stenosis (P=0.047). CONCLUSIONS: The results show that the CX3CR1 M280 is an independent genetic risk factor for ICA occlusive disease and that I249 is involved in the stability of carotid plaques. Even if obtained from a relatively limited patient series, these results might have relevant implications for treatment of ICA stenosis and possibly prevention of carotid related stroke. Further prospective cross-sectional studies are needed to confirm these results.

Matrix metalloproteinase-1 and matrix metalloproteinase-3 gene promoter polymorphisms are associated with carotid artery stenosis.

BACKGROUND AND PURPOSE: The matrix metalloproteinases (MMPs) are a family of enzymes that are important in the resorption of extracellular matrix and are involved in atherogenesis. Recently, 2 common polymorphisms on MMP-1 (1G/2G) and MMP-3 (5A/6A) gene promoters have been described. The aim of this study was to investigate a possible association between MMP polymorphisms and increased risk of internal carotid artery (ICA) stenosis. METHODS: We studied 91 patients consecutively recruited for ICA stenosis who had undergone carotid endarterectomy and 133 subjects without ICA stenosis (controls). Polymorphic genotypes were determined by polymerase chain reaction and sequencing analysis. RESULTS: The frequency of the 6A allele was significantly different between cases and controls: 0.62 and 0.50, respectively (odds ratio [OR], 1.58; 95% CI, 1.08 to 2.33; P=0.017). The frequency of 6A/6A genotype was significantly higher in cases with involvement of both carotids (OR, 3.13; 95% CI, 1.14 to 8.5; P=0.026) and in patients with stenosis >70% (OR, 2.55; 95% CI, 1.07 to 6.07; P=0.033). No significant differences were observed in MMP-1 distribution. Patients who were homozygous for both the 6A and 2G alleles had an elevated relative risk of ICA stenosis (OR, 2.66; 95% CI, 1.23 to 5.72; P=0.016). Multiple logistic regression analysis using the common risk factors and the 6A and 2G allele variants revealed that the 6A allele was an independent risk factor for ICA stenosis (P=0.049). When 6A/6A and 2G/2G were combined, the risk factor for ICA stenosis was 3-fold higher (OR, 3.31; 95% CI, 1.48 to 7.42; P=0.004). CONCLUSIONS: Homozygosity for the 6A allele of the MMP-3 promoter is associated with carotid stenosis and, in association with MMP-1 2G homozygosity, predicts an increased risk of ICA stenosis. Even if obtained from a relatively limited patient series, these results might have relevant implications for treatment of ICA stenosis and possibly prevention of carotid-related stroke.

Independent risk factor for moderate to severe internal carotid artery stenosis: T786C mutation of the endothelial nitric oxide synthase gene.

BACKGROUND: NO synthesized from L-arginine by the constitutive endothelial NO synthase (eNOS) plays a key role in the atherosclerotic process. We investigated whether common variants in the NOS3 gene (a T786C mutation in the 5' flanking region and the polymorphism on exon 7 that produced the Glu298Arg polymorphism in the protein) are associated with an increased risk of moderate to severe internal carotid artery (ICA) stenosis. METHODS: We studied 88 patients consecutively operated for ICA stenosis and 133 healthy controls. A T786C mutation in the 5' flanking region and the polymorphism in exon 7 that produces the Glu298Asp polymorphism in the protein were explored by PCR and fluorescent probe analysis. RESULTS: Genotype distribution was significantly different between patients and controls only for T786C, the CC genotype frequency being 26% and 13%, respectively [odds ratio (OR), 2.26; 95% confidence interval (CI), 1.14-4.46; P = 0.018]. Moreover, the CC genotype was significantly more frequent in a subgroup of patients with ulcerative plaques compared with patients with nonulcerative lesions (44% vs 17%; OR, 3.82; 95% CI, 1.79-8.14; P = 0.003). Multiple logistic regression analysis using the most frequent risk factors and the eNOS gene variant showed that the CC genotype is an independent risk factor for ICA stenosis (P = 0.023). CONCLUSION: C allele homozygosity in position 786 of the eNOS promoter seems to be an independent risk factor for the development of moderate to severe ICA stenosis, especially ulcerative lesions.