Hemochromatosis-causing mutations C282Y and H63D are not risk factors for atherothrombotic cerebral infarction

BACKGROUND

It has been suggested that iron metabolism may be involved in the pathogenesis of atherothrombotic cerebral infarction (ACI). The C282Y and H63D mutations in the hemochromatosis (HFE) gene are associated with increased serum iron levels and net iron accumulation. The aim of this study was to test the hypothesis that the C282Y and H63D mutations in the HFE gene are risk factors for ACI in a Slovene population.

MATERIAL/METHODS

The C282Y and H63D HFE gene mutations were tested in 96 Caucasian patients who had suffered an acute cerebral infarction, later confirmed as ACI, and 115 control subjects. Genotypes were determined by electrophoresis of the DNA digestion products from RsaI (C282Y) and MboI (H63D).

RESULTS

We failed to demonstrate that the C282Y and H63D mutations were risk factors for ACI in Caucasians. The percentage of C282Y and H63D genotypes (dominant model) in ACI-cases (C282Y: 7.3%, n=7; H63D: 28.1%, n=27) did not differ significantly (P=0.9 and P=0.7 respectively) from that of the controls (C282Y: 7.0%, n=8; H63D: 26.1%, n=30). Logistic regression analysis revealed that arterial hypertension, diabetes, and cigarette smoking are independent risk factors for ACI, whereas the C282Y and H63D HFE gene mutations are not.

CONCLUSIONS

We provided evidence that the C282Y and H63D HFE gene mutations were not risk factors for ACI in this Slovene population.

Using literature-based discovery to identify disease candidate genes

We present BITOLA, an interactive literature-based biomedical discovery support system. The goal of this system is to discover new, potentially meaningful relations between a given starting concept of interest and other concepts, by mining the bibliographic database MEDLINE. To make the system more suitable for disease candidate gene discovery and to decrease the number of candidate relations, we integrate background knowledge about the chromosomal location of the starting disease as well as the chromosomal location of the candidate genes from resources such as LocusLink and Human Genome Organization (HUGO). BITOLA can also be used as an alternative way of searching the MEDLINE database. The system is available at http://www.mf.uni-lj.si/bitola/.

Y microdeletions in the Istria county, Croatia

AIM

To establish the frequency of Y chromosome microdeletions in an unselected group of infertile Croatian men.

METHODS

An unselected group of 105 patients (male partners of infertile couples), both with idiopathic and non-idiopathic infertility, consecutively referred to the outpatient infertility clinic, gynecology department, General Hospital Pula, Istria County, Croatia, was examined for the presence or absence of Y chromosome microdeletions by polymerase chain reaction analysis.

RESULTS

One of the 105 men (0.95%, 95% CI = 0.17-5.2%) was found to have a microdeletion.

CONCLUSION

A low frequency of Y chromosome microdeletions was found in the group of unselected infertile Croatian men.

Oestrogen receptor dinucleotide (TA) polymorphism affects total and LDL cholesterol but does not predict premature myocardial infarction in Caucasian men

OBJECTIVE

The aim of this association study was to test the hypothesis whether the oestrogen receptor gene dinucleotide (TA) polymorphism is a risk factor for premature myocardial infarction in Caucasian men. Moreover, we investigated an association between oestrogen receptor gene dinucleotide (TA) polymorphism and serum lipid levels.

METHODS AND RESULTS

One hundred and thirty men with premature myocardial infarction were compared with healthy men. Cases and controls did not demonstrate a statistically significant difference in distribution of the oestrogen receptor dinucleotide (TA) gene polymorphism alleles. Neither did we demonstrate the length of the dinucleotide (TA) repeats of the oestrogen gene to be associated with premature myocardial infarction in Caucasian men. Subjects with larger alleles (both alleles of > or =19 repeats) differed from subjects with other genotypes in serum total and LDL cholesterol, but not in HDL cholesterol and triglycerides.

CONCLUSIONS

Despite an association between the oestrogen receptor gene dinucleotide (TA) polymorphism in the regulatory region of the alpha oestrogen receptor gene and serum total and LDL cholesterol, our study suggests that the oestrogen polymorphism is not associated with premature myocardial infarction in Caucasian men.

Human Y-specific STR haplotypes in the Western Croatian population sample

Nine Y-chromosome STR loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385 and YCAII) were analysed in a sample of 101 unrelated males from Croatia. Allelic frequencies and gene diversities for each Y-STR locus and haplotype diversity were determined. Ninety-one different haplotypes were obtained from 101 unrelated males and 84 haplotypes were unique. Three most common haplotypes were shared by 3% of the sample, one of them was not found in the online Y-STR Haplotype Reference Database (http://www.ystr.org/).

Genetic markers of restenosis after coronary angioplasty and after stent implantation

Apart from coronary artery bypass grafting, percutaneous transluminal coronary angioplasty (PTCA) and intracoronary stent placement are well established treatment strategies for CAD. Substantial differences exist in the mechanisms of restenosis between conventional PTCA and stenting. Arterial remodeling is the main contributor to lumen re-narrowing after PTCA, whereas neointimal hyperplasia is almost the sole mechanism of restenosis after stenting. Several reports have demonstrated that genetic factors may be involved in the pathogenesis of restenosis after PTCA and in-stent restenosis. In this review the candidate genes involved in the pathogenesis of restenosis are analyzed as potential genetic markers of restenosis after PTCA and in-stent restenosis. The I/D angiotensin-I converting enzyme gene polymorphism, gene polymorphisms of the endothelial nitric oxide synthase (Glu298Asp, -786T>C), the glycoprotein IIIa PlA1/A2 gene polymorphism, gene polymorphism of the estrogen (PvuII), allele 2 of the interleukin-1ra gene, and the GT repeats in heme oxygenase-1 gene promoter may be used as genetic markers for in-stent-restenosis. On the other hand, only the stromelysin-1 5A/6A gene polymorphism and allele 2 of the interleukin-1ra gene may be used as a genetic marker for restenosis after PTCA.

Fibrinogen polymorphisms TaqI, HaeIII and BclI are not associated with a higher risk of deep vein thrombosis

High fibrinogen is recognised as a risk factor for atherosclerosis. It seems that high fibrinogen is also a risk factor for deep vein thrombosis (DVT). It has been shown that certain polymorphisms in fibrinogen genes can influence the fibrinogen level. In this study, fibrinogen levels and the frequency of the polymorphisms TaqI, HaeIII and BclI were studied in 114 patients with DVT and 244 healthy subjects. In non-smokers, fibrinogen levels above 5 g/l were associated with an increased risk of DVT (odds ratio 3.3, 95% confidence interval 1.6-7.0). The frequencies of common alleles were similar in patients and healthy subjects for all polymorphisms. An association between fibrinogen levels and the polymorphisms TaqI, HaeIII and BclI was found in healthy subjects, but not in the patients. It was concluded from these data that the polymorphisms TaqI, HaeIII and BclI are not major risk factors for DVT.

Aldose reductase (AC)n gene polymorphism and susceptibility to diabetic retinopathy in Type 2 diabetes in Caucasians

Genetic factors are implicated in the development of diabetic retinopathy, and the aldose reductase (AC)n gene is a candidate gene for the development of diabetic retinopathy in patients with Type 2 diabetes. In the association study, a relationship between the aldose reductase (AC)n gene polymorphism and the development of diabetic retinopathy in patients with Type 2 diabetes were studied. We tested the hypothesis whether the Z-2 allele of the aldose reductase gene is a risk factor for the development of diabetic retinopathy in a group of Caucasian participants with Type 2 diabetes. Two hundred and five participants with Type 2 diabetes were enrolled in the study: 124 participants with Type 2 diabetes with diabetic retinopathy were compared with 81 diabetic participants without retinopathy with diabetes duration of more than 10 years. Eight alleles of the aldose reductase (AC)n gene polymorphism were detected: Z+6, Z+4, Z+2, Z, Z-2, Z-4, Z-6, and Z-8. An increased frequency of the Z-2 allele was found in the patients with diabetic retinopathy compared with the patients without diabetic retinopathy (39.1% vs. 26.5%; P value=.009, chi2=6.9). Our results suggest that the Z-2 allele of the aldose reductase gene is a risk factor for the development of diabetic retinopathy in a group of Caucasian participants with Type 2 diabetes.

Are the T/C polymorphism of the CYP17 gene and the tetranucleotide repeat (TTTA) polymorphism of the CYP19 gene genetic markers for premature coronary artery disease in Caucasians?

Gender differences in CAD have been clearly documented, and sex hormones have been recognized to influence the risk of CAD. The cytochrome P450c17alpha gene (CYP17) and the CYP19 gene influence concentrations of sex hormones. In this cross-sectional association study we tested the hypothesis whether the T/C polymorphism of the CYP17 gene and the tetranucleotide repeat (TTTA) polymorphism of the CYP19 gene are genetic markers for CAD in Caucasians. The TT genotype of the CYP17 gene polymorphism was not associated with premature CAD in men and women combined (OR 0.9; 95% CI = 0.6-1.4; P = 0.7), in men only (OR 1; 95% CI = 0.6-1.8; P = 0.7), and in women only (OR 0.8; 95% CI = 0.5-1.4; P = 0.4). The tetranucleotide repeat (TTTA) CYP19 gene polymorphism was not associated with premature CAD. Moreover, the genotypes containing the longer alleles (A6 or A7) were not associated with a lower incidence of CAD, and the genotypes containing the shorter alleles (A1 or A2) were not over-represented in the CAD patients. We may conclude that in Caucasian subjects neither the T/C CYP17 gene polymorphism nor the tetranucleotide repeat (TTTA) polymorphism of the CYP19 gene contributes to the genetic susceptibility to CAD, therefore they may not be used as genetic markers for CAD risk assessment.

Carotid artery intima-media thickness and angiotensin-converting enzyme gene polymorphism in the offspring of parents with premature stroke

AIM

To determine some common cardiovascular risk factors, alterations in the measurements of intima-media thickness (IMT) and the distribution of the angiotensin-converting enzyme (ACE) polymorphism in children of parents with premature stroke, and to investigate the cardiovascular risk of these children and the potential need for some preventive measures.

METHODS

A family history of cardiovascular disease represents a cardiovascular risk factor in the offspring. This association has not yet been clearly determined for cerebrovascular accidents. New technology allows us to investigate the risk for cardiovascular disease at an early presymptomatic stage. We applied the measurement of IMT of carotid arteries by ultrasound imaging and the determination of the ACE insertion/deletion (I/D) polymorphism in blood to evaluate the predisposition for cerebrovascular disease in the offspring of patients with previous stroke. We investigated 58 subjects whose parents had experienced a cerebrovascular accident before the age of 45 y and compared them with a matched control group whose parents had not suffered a stroke.

RESULTS

The results of IMT at various sites of the carotid arteries and the genotype distribution of the ACE gene were not significantly different between the study group and the control group. In addition, no differences were found in the serum levels of lipid fractions or other biochemical variables.

CONCLUSION

We conclude that determination of the carotid IMT and of the ACE I/D polymorphism do not permit discrimination of the cardiovascular risk in children of parents with or without premature stroke.

Early sympathetic hyperactivity in Huntington's disease

To investigate whether Huntington's disease (HD) affects autonomic nervous system (ANS) functioning 33 subjects with positive genetic test results were studied. The subjects were classified according to Shoulson and Fahn (S&F) HD disability scale into three subgroups: subgroup 1 (eight asymptomatic gene carriers), subgroup 2 (13 mildly disabled HD patients) and subgroup 3 (eight moderately and four severely disabled HD patients). A battery of cardiovascular autonomic tests (Valsalva maneuver, deep breathing test, sustained handgrip test, orthostatic test) and the spectral analysis of heart rate variability (HRV) were performed. The results were compared with a group of matched controls. In subgroup 1, there was a higher power of low-frequency band (LFB) (P < 0.05). In subgroup 2 a higher power of LFB was detected, LFB/high-frequency band (HFB) coefficient was increased and the blood pressure response to sustained handgrip was elevated (P < 0.05). Subgroup 3 showed significantly lower blood pressure response to sustained handgrip, lower respiratory (P < 0.05) and orthostatic ratio (P < 0.01). Our results suggest that sympathetic hyperfunction is present in asymptomatic gene carriers and mildly disabled HD patients. Contrary to that, ANS hypofunction was found in advanced HD patients.

Diagnostic test for Y chromosome microdeletion screening in male infertility

Despite the current lack of understanding the mechanism of deleterious effects of Y chromosome microdeletions and their prognostic influence on male subfertility, the Y chromosome microdeletion test is widely used in the diagnostic evaluation of male subfertility. However, currently used diagnostic schemes have not been sufficiently evaluated for their diagnostic performance. The purpose of this study was to analyze a large database of published Y chromosome microdeletions to develop the optimal screening strategy for male subfertility. Therefore, we created a database from genetic and clinical data published in 52 peer-reviewed studies reporting on 512 cases with Y chromosome microdeletions. We developed a computerized procedure with the goal of minimizing the number of genetic markers included in the diagnostic set while maximizing the detection rate in patients with microdeletions. We estimate that 85.6% of all published Y chromosome microdeletions can be covered by a set of six genetic markers (sY84, sY127, sY152, RBMY1, sY147, sY254-DAZ). Inclusion of additional markers brings relatively little to the sensitivity of the test and is potentially related to the population origin.

CTG amplification in the DM1PK gene is not associated with idiopathic male subfertility

BACKGROUND

Polymorphism in the CTG triplet number in the myotonic dystrophy type 1 (DM1PK) gene has been proposed as being associated with idiopathic azoospermia. The aim of this study was to investigate whether the CTG trinucleotide amplification in the DM1PK gene is associated with male subfertility.

METHODS

We evaluated 107 subfertile patients, male partners of infertile couples, affected by non-obstructive azoospermia (n = 38) and oligoasthenoteratozoospermia (OAT) (n = 69), and 102 men with proven fertility. Main outcome measures were CTG repeat size in the DM1PK gene, testicular volume, sperm concentration, rapid progressive motility, normal morphology, serum FSH levels, testicular histology and Johnsen score.

RESULTS

In subfertile males, no minimal mutation or mutation carriers were found. The difference in the number of CTG repeat lengths between the groups was not statistically significant (P = 0.825). There was no correlation between the number of CTG repeats and the clinical parameters of subfertile patients: testicular volume, sperm concentration, rapid progressive motility, normal morphology, FSH level, testicular histology and Johnsen score.

CONCLUSIONS

The number of CTG repeats in the normal or mutational range of DM1PK gene is associated with neither idiopathic male subfertility nor with clinical characteristics of male subfertility.

Factor V Leiden, prothrombin 20210G --> A, methylenetetrahydrofolate reductase 677C --> T and plasminogen activator inhibitor 4G/5G polymorphism in women with pregnancy-related venous thromboembolism

OBJECTIVE

To establish the prevalence of inherited and acquired risk factors for development of venous thromboembolism (VTE) in pregnancy and the puerperium.

STUDY DESIGN

In a retrospective study, 30 women with a history of objectively confirmed venous thromboembolism during pregnancy or the puerperium were studied. Fifty-six women with normal pregnancies were included as controls. Antithrombin, protein C, protein S, lupus anticoagulants, homocysteine, factor V Leiden mutation, prothrombin 20210G-->A polymorphism, methylenetetrahydrofolate reductase (MTHFR) 677C-->T polymorphism and the -675 (4G/5G) polymorphism in plasminogen activator inhibitor 1 gene were analysed.

RESULTS

At least one thrombophilic defect was observed in 16 (53.3%) cases and in 12 (21.4%) controls (P=0.003); factor V Leiden in 8 (26.7%) cases and 3 (5.7%) controls (P=0.009); prothrombin 20210G-->A polymorphism in 8 (26.7%) cases and 4 (7.5%) controls (P=0.021) and antithrombin deficiency in 4 (13.3%) cases and in 1 (1.8%) control (P=0.029). Other inherited and acquired risk factors were similarly distributed among cases and controls.

CONCLUSION

Women with pregnancy-related venous thromboembolism have an increased prevalence of inheritable thrombophilic defects predisposing them to an increased risk of thrombosis.

Genealogical study of myotonic dystrophy in Istria (Croatia)

High prevalence of myotonic dystrophy (DM) of 18.1 per 100,000 has been found in Croatian region Istria, a region where a great mixture of nations occurred over the last three centuries. The objective of this study was to test the hypothesis of common ancestry in Istrian DM families. Pedigrees were constructed on the basis of extensive family history obtained from the patients in all Istrian DM families. Church records were consulted in order to improve genealogical reconstruction. Additionally, we performed haplotype analyses with two intragenic and three extragenic DNA polymorphic markers. A common ancestor couple for three of nine nucleus families was found eight generations backward, which was supported by haplotype analysis. In spite of finding an evidence of common ancestry in Croatian Istria we argue that the phenomenon of founder effect is not sufficient to explain the high DM prevalence in Istria.

Apolipoprotein E gene polymorphism effects triglycerides but not CAD risk in Caucasian women younger than 65 years

The pathogenesis of CAD is similar in man and woman, yet some risk factors have a greater impact on the CAD risk in woman than in man. In this study we assessed the effect of the apoE gene polymorphism on lipid metabolism and risk for CAD in women younger than 65 years (premature CAD). In a cross-sectional case-control study, 147 female Caucasian patients with premature CAD (confirmed by coronarography) were compared with a control group of 114 healthy Caucasian women. The apoE allele frequencies of patients vs. controls were 5.1% vs. 5.7% for 2, 85.4% vs. 83.3% for 3, and 9.5% vs. 11% for epsilon4. The subjects with epsilon2/3 genotype had statistically significantly higher triglycerides levels than the subjects with epsilon3/3 genotype (2.23 +/- 2.13 mmol.L(-1) vs. 1.73 +/- 0.84 mmol.L(-1); p<0.05). Logistic regression analysis revealed no association between risk genotypes (3/4 and 4/4) of the apoE gene polymorphism and CAD risk (OR 0.9; 95% CI 0. 5-1.7, P=0.7). We observed metabolic clustering of diabetes mellitus, arterial hypertension, higher BMI and triglycerides, and lower HDL cholesterol in the CAD group compared to the control group. Arterial hypertension, diabetes, HDL cholesterol level, and BMI were independent risk factors for premature CAD in female population, whereas, the risk genotype of the apoE gene polymorphism was not. In conclusion, in Slovene women risk genotypes of the apoE gene polymorphism are not associated with premature CAD; a metabolic clustering of diabetes, HDL, triglycerides and arterial hypertension is frequently present in Caucasian women with premature CAD.

A Gly482Ser polymorphism of the peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC-1) gene is associated with type 2 diabetes in Caucasians

The PGC-1 gene has been implicated in the regulation of several genes controlling energy metabolism. The prevalent Gly482Ser polymorphism of the PGC-1 gene has been shown to be associated with type 2 diabetes in some but not all studies. The aim of this study was to analyse whether the Gly482Ser variant is a risk factor for development of type 2 diabetes in Slovene population (Caucasians). Genotyping of the Gly482Ser polymorphism was performed for 545 subjects: 305 patients with type 2 diabetes and 240 non-diabetic controls. The Gly482Ser genotype distribution in patients with type 2 diabetes (AA = 11.5%, AG = 42.3%, GG = 46.2%) differed from genotype distribution in non-diabetic controls (AA = 6.3%, AG = 46.3%, GG = 47.5%), and the AA genotype was associated with 1.9-times increased risk of type 2 diabetes (95% confidence interval 1.0-3.6; P = 0.036). In conclusion, we suggest that the AA genotype of the Gly482Ser polymorphism of the PGC-1 gene should be considered as a risk factor for the development of type 2 diabetes in Caucasians.

Copy number of DAZ genes in Slovenian and Bosnian general population

Deletions of two of four DAZ (Deleted in AZoospermia) gene copies located on the Y chromosome were associated with spermatogenic failure, but the information on DAZ copy number is still very scarce. The aim of this study was to determine the frequency of partial DAZ gene deletions and to analyze the existence of duplications in general Slovenian and Bosnian population. To answer these questions, we used real time PCR. We analyzed 100 male samples from Slovenian and Bosnian general population. The incidence of two DAZ gene copies was 6% (3/50) in Slovenian population. The incidence of more than four DAZ genes was 2% (1/50) in Slovenian population and 8% (4/50) in Bosnian population. Observed differences have not reached statistical significance. In conclusion we demonstrate that DAZ genes are not only prone to deletions but also to duplication events. Further studies are needed to estimate the prevalence of these mutations and its' relevance to male infertility.

Haemochromatosis-causing mutations C282Y and H63D are not risk factors for coronary artery disease in Caucasians with type 2 diabetes

Iron metabolism might be involved in the pathogenesis of CAD, and C282Y and H63D mutations in the HFE gene are associated with increased serum iron levels and net iron accumulation. The aim of this study was to look for a relationship between the C282Y and H63D gene mutations of the HFE gene and coronary artery disease (CAD) in a group of patients with type 2 diabetes lasting more than 10 years. The C282Y and H63D gene mutations were tested in 338 Caucasians with type 2 diabetes: 156 cases with CAD and 182 subjects with no history of CAD. The C282Y and the H63D HFE gene distributions in patients with CAD (C282Y: YY 0.6%, CY 9.0%, CC 90.4%; H63D: DD 3.8%, HD 21.8%, HH 74.4%) were not significantly different from those of diabetic subjects without CAD (C282Y: YY 0%, CY 8.2%, CC 91.8%; H63D: DD 2.2%, HD 20.3%, HH 77.5%). In conclusion, we failed to demonstrate that the C282Y and H63D HFE gene mutations were risk factors for CAD in Caucasians with type 2 diabetes lasting longer than 10 years.

BglII gene polymorphism of the alpha2beta1 integrin gene is a risk factor for diabetic retinopathy in Caucasians with type 2 diabetes

Platelets are thought to be involved in the pathogenesis of diabetic retinopathy. The BglII gene polymorphism of the alpha2beta1 integrin, which is a platelet collagen receptor, has been suggested as a genetic risk factor for diabetic retinopathy in Japanese subjects. The aim of this study was to look for a relationship between the BglII gene polymorphism of the alpha2beta1 integrin gene and the development of diabetic retinopathy in Caucasians with type 2 diabetes. Subjects with type 2 diabetes and diabetic retinopathy (n=163) were compared with diabetic subjects without diabetic retinopathy (n=95). A significantly higher frequency of the BglII (+/+) genotype of the gene polymorphism of the alpha2beta1 integrin gene was found in patients with diabetic retinopathy compared with patients without diabetic retinopathy (19.6% vs 7.4%; P=0.008). The present study demonstrates that the BglII (+/+) genotype of the gene polymorphism of the alpha2beta1 integrin gene is an independent risk factor (odds ratio: 2.4, 95% confidence interval 1.0-6.0; P<0.05) for diabetic retinopathy in Caucasians with type 2 diabetes.

Relation of CTG expansion and clinical variables to electrocardiogram conduction abnormalities and sudden death in patients with myotonic dystrophy

We prospectively followed 63 patients with myotonic dystrophy (DM) after establishing diagnosis of DM for an average 8 years in an attempt to detect conduction disturbances (by electrocardiography and/or Holter monitoring) and sudden cardiac events (sudden death, cardiac syncope) and correlate them to potential predicting factors (CTG repeat expansion in the myotonin protein kinase gene and several clinical variables: clinical type and duration of DM, age and sex). Twenty-six patients developed conduction disturbances, five patients died suddenly, and two patients experienced cardiac syncope necessitating urgent implantation of pacemaker. Analysis showed no significant correlation between conduction disturbances and/or cardiac events and CTG expansion. Furthermore, no correlation was found with type of DM, whereas conduction disturbances and sudden cardiac events correlated with patients' age, duration of disease and male sex. Results on our cohort of DM patients show that CTG expansion has no role in predicting neither conduction abnormalities nor sudden death. It seems that risk of sudden death increases with duration of disease and age, and that risk is higher in male patients.

The - 429 T/C and - 374 T/A Gene Polymorphisms of the Receptor of Advanced Glycation End Products Gene are not Risk Factors for Diabetic Retinopathy in Caucasians with Type 2 Diabetes

OBJECTIVE

The aim of this study was to look for a relationship between the - 429 T/C and the - 374 T/A gene polymorphisms of the receptor of advanced glycation end products (RAGE) gene and the development of diabetic retinopathy in Caucasians with type 2 diabetes.

MATERIALS AND METHODS

One hundred and sixteen subjects with type 2 diabetes and diabetic retinopathy were compared to 70 diabetic subjects without diabetic retinopathy. Additionally, 76 subjects with proliferative diabetic retinopathy (a subgroup of diabetic retinopathy) were compared to 70 diabetic subjects without diabetic retinopathy.

RESULTS

The - 429 T/C and the - 374 T/A RAGE gene distributions in patients with diabetic retinopathy (- 429 T/C: CC 0.9%, TC 25.9%, TT 73.2%; - 374 T/A: AA 9.5%, TA 47.4%, TT 43.1%) were not significantly different from those of diabetic subjects without retinopathy (- 429 T/C: CC 0%, TC 25.7%, TT 74.3%; - 374 T/A: AA 15.7%, TA 42.9%, TT 41.4%). Moreover, the - 429 T/C and the - 374 T/A RAGE gene distributions in patients with proliferative diabetic retinopathy were not statistically significantly different from those in diabetic subjects without retinopathy.

CONCLUSION

Our study failed to demonstrate an association between either - 429 T/C or - 374 T/A gene polymorphism of the RAGE gene and diabetic retinopathy in Caucasians with type 2 diabetes. Additionally, we failed to demonstrate an association between either - 429 T/C or - 374 T/A gene polymorphism of the RAGE gene and proliferative diabetic retinopathy in Caucasians with type 2 diabetes.

A hemochromatosis-causing mutation C282Y is a risk factor for proliferative diabetic retinopathy in Caucasians with type 2 diabetes

Iron metabolism might be involved in the pathogenesis of type 2 diabetes and in the pathogenesis of diabetic retinopathy. C282Y and H63D mutations in the hemochromatosis (HFE) gene are associated with increased serum iron levels and consequently with hereditary hemochromatosis. In the present study, we searched for a relationship between C282Y and H63D gene mutations and the development of proliferative diabetic retinopathy in Caucasians with type 2 diabetes. For this purpose, 90 subjects with type 2 diabetes with proliferative diabetic retinopathy (PDR) were compared to 133 diabetic subjects without PDR. There was a significantly higher frequency of the C282Y heterozygotes in patients with PDR compared to subjects without it (OR=3.0, 95% CI=1.2-8.0; p=0.02), whereas no association was demonstrated between PDR and H63D genotypes (OR=1.1, 95% CI=0.6-2.2; p=0.7). Logistic regression analysis revealed that the C282Y mutation was a significant independent risk factor for the development of PDR (OR=6.1, 95% CI=1.2-30.5; p=0.027). These data suggest that heterozygosity for C282Y might be a novel risk factor for PDR in Caucasians with type 2 diabetes.

Estrogen receptor dinucleotide (TA) polymorphism does not predict premature myocardial infarction in Caucasian women

In this association study, we tested the hypothesis whether the estrogen receptor gene dinucleotide (TA) polymorphism is a risk factor for premature myocardial infarction in Caucasian women. We also investigated the relationships between estrogen receptor gene dinucleotide (TA) polymorphism and serum lipid levels. One-hundred and forty-one women with premature myocardial infarction were compared with healthy women. Cases and controls did not demonstrate a statistically significant difference in distribution of the estrogen receptor dinucleotide (TA) gene polymorphism alleles. Neither could we demonstrate the length of the dinucleotide (TA) repeats of the estrogen gene to be associated with premature myocardial infarction in Caucasian women. Subjects with larger alleles (both alleles of > or = 19 repeats) did not differ in serum lipid levels (total, LDL, HDL cholesterol and triglycerides) from subjects with other genotypes. We may conclude that in Caucasian women the length of the dinucleotide (TA) repeat in the regulatory region of the alpha-estrogen receptor gene is neither associated with premature myocardial infarction nor with serum lipid levels.