ABCA3 and LZTFL1 Polymorphisms and Risk of COVID-19 in the Czech Population

SARS-CoV-2 infection, which causes the respiratory disease COVID-19, has spread rapidly from Wuhan, China, since 2019, causing nearly 7 million deaths worldwide in three years. In addition to clinical risk factors such as diabetes, hypertension, and obesity, genetic variability is an important predictor of disease severity and susceptibility. We analyzed common polymorphisms within the LZTFL1 (rs11385942) and ABCA3 (rs13332514) genes in 519 SARS-CoV-2-positive subjects (164 asymptomatic, 246 symptomatic, and 109 hospitalized COVID-19 survivors) and a population-based control group (N?=?2,592; COVID-19 status unknown). Rare ABCA3 AA homozygotes (but not A allele carriers) may be at a significantly increased risk of SARS-CoV-2 infection [P?=?0.003; OR (95 % CI); 3.66 (1.47-9.15)]. We also observed a borderline significant difference in the genotype distribution of the LZTFL1 rs11385942 polymorphism (P?=?0.04) between the population sample and SARS-CoV-2-positive subjects. In agreement with previous studies, a nonsignificantly higher frequency of minor allele carriers was detected among hospitalized COVID-19 subjects. We conclude that a common polymorphism in the ABCA3 gene may be a significant predictor of susceptibility to SARS-CoV-2 infection.

Macrovascular and microvacular changes in diabetes mellitus type 1 are modified by the gene for connexin 37 in men but not in women

Introduction

Diabetes mellitus type 1 (DMT1) is a strong risk factor for macrovascular and microvascular disease. These vascular pathologies can be strongly modified by genetic factors. One of intensively investigated candidate genes is the gene for connexin37 (Cx37) (C1019>T (Pro319>Ser). The role of this gene in cardiovascular disease and diabetes mellitus had been already described in several different populations, but not in patients with DMT1.

Purpose

To determine whether the presence of macrovascular and microvascular changes is modified by Cx37 gene polymorphism in middle aged men and women diagnosed with DMT1 of similar age and with similar duration of DMT1.

Methods

In 253 men (mean age 43.0±14.5 years; mean duration of diabetes 22.6±14.0 years) and 245 women (mean age 43.9±12.9 years; mean duration of diabetes 21.3±10.5 years) macrovascular disease was measured by duplex B-Mode ultrasound and classified as Belcaro score (1–4) in carotid and femoral arteries. Microvascular disease was assessed by the presence of retinopathy, nephropathy, neuropathy and diabetic foot. Cx37 gene polymorphism was established by PCR.

Results

In men, in CC homozygotes we observed more advanced macrovascular changes in carotid arteries (Belcaro score more than 2) than in CT heterozygotes/TT homozygotes (7.5 vs. 15.2%; p=0.031). No significant differences were found in changes of carotid arteries in women and in changes of femoral arteries both in men and women. Regarding microvascular changes, in men, in CC homozygotes, the diabetic foot was diagnosed more frequently than in CT heterozygotes/TT homozygotes (7.4 vs. 16.1%; p=0.046). No significant differences were found in women and in other types of microvascular disease both in men and women.

Conclusion

These results indicate that macrovascular and microvascular changes in DMT1 can be modified by Cx37 gene polymorphism in men, but not in women.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by the Ministry of Health of the Czech Republic, grant No. NU20-01-00083 and by Ministry of Health of the Czech Republic under its conceptual development of the research organization program (Institute for Clinical and Experimental Medicine–IKEM, IN 00023001. All rights reserved.

Triglycerides, polymorphisms and the risk of acute coronary syndrome in the Czech population

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Supported by Ministry of Health, Czech Republic - conceptual development of research organization 64165, General University Hospital in Prague, Czech Republic

Background and Aims

Elevated levels of plasma triglycerides (TG) have been identified as a risk factor for the development of cardiovacular disease, including acute coronary syndrome (ACS). Final TG levels are largely influenced by genetic factors. The most important genetic factors influencing TG levels in the Czech population are the polymorphisms in APOA5, GCKR, MAP3K1, CTF1, CYP26A1, LRP1, CILP2, LIPC, APOE, GALNT2 and LPL genes.

Methods

The variants in mentioned genes were analyzed in total 929 patients with ACS and 936 healthy controls (study post-MONICA). Only adult men under the age of 65 were included in the study.

Results

Plasma TG levels did not differ significantly between patients and controls (1.96 ± 1.30 mmol/L vs. 2.06 ± 1.47 mmol/L). CYP26A1 AA homozygotes (rs2068888) were more common (P <0.05; OR; 95% CI = 1.34; 1.03-1.74) among patients. The differences in the frequencies of the other variants were not statistically significant, however, with the exception of GCKR, LRP1, MAP3K1, GALNT2 and LPL variants, they were used to calculate the risk genetic score due to the higher OR value (above 1.15). Subjects with a score of 8 or more vs less than 3 occurred more frequently among patients with ACS than among controls (60% vs. 30%, P = 0.005; OR; 95% CI – 2.03; 1.24 – 3.31).

Conclusions

Genetic score calculated from six selected variants associated with plasma TG levels is a significant predictor of ACS in Czech Caucasian males.

Cholesterol and the risk of acute coronary syndrome. Mendelian randomisation in the Czech population

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Health, Czech Republic

Introduction

Increased plasma cholesterol levels are considered as a risk factor for the development of cardiovascular diseases, including acute coronary syndrome (ACS). However, observational studies in recent years have often found no increased LDL-cholesterol values in ACS patients compared to controls. Final cholesterol levels are largely modified by genetic factors, so they can be used to demonstrate (based on Mendelian randomization) whether the link between plasma cholesterol and MI risk is still present.

Methods

In our study, we analysed LDL-R (rs6511720), CILP2/PBX4 (rs16996148), APOB (rs693) and SORT-1 (rs646776) variants in a total of 939 patients with ACS and 1,191 healthy controls (post-MONICA study). Only men aged 18-65 years were included in the study.

Results

Patients with ACS had significantly lower total cholesterol levels than controls (4.8 ± 1.1 vs. 5.7 ± 1.1 mmol / L; P <0.001). Total and LDL-cholesterol were not higher in patients even after adjusting for age, BMI and dyslipidemic treatment. We confirmed a significant effect of all analysed variants on LDL-cholesterol levels (all P <0.01). None of the four analysed variants significantly affected the risk of MI (P values between 0.10 and 0.58). Individuals with at least seven cholesterol-raising alleles had a slightly increased risk of ACS compared to others (OR, 95% CI; 1.26, 1.06-1.51; P = 0.01).

Conclusion

Variants within the genes for LDL-R, CILP2 / PBX4, APOB and SORT-1 are significant genetic determinants of LDL-cholesterol levels in the population of Czech men. After a population-wide reduction in cholesterol levels, these levels no longer seem to be a serious problem in determining ACS, and interventions to reduce other types of risk should be given more attention.

[Cognitive functions and modifiable risk factors for chronic non-communicable diseases in ageing in a Russian population sample.]

We aimed to investigate the relationship between the indicators of cognitive functions (CF) and modifiable risk factors for chronic non-communicable diseases (NCD) in a cross-sectional analysis in the urban Russian population sample aged 55-84 years. The study investigated a random sample of 3 153 people (men and women 55-84 years old) from a general population cohort of Novosibirsk residents; a sample was examined within the international project HAPIEE. The study protocol included standardized neuropsychological tests (quantitative assessment of memory, semantic verbal fluency, attention and processing speed) and standardized assessment of risk factors, history and treatment of cardiovascular disease and NCD. In cross-sectional analysis we observed a positive relationship of CF indices with level of education and an inverse relationship with metabolic risk factors and smoking in both sexes. The level of total cholesterol and moderate alcohol consumption had positive relationship with CF indices in women. These associations were independent from age and other factors.

[The frequency and profile of drug treatment in subjects with dyslipidemias and cardimetabolic diseases in an urban russian population older then 55 years]

Aim      To analyze frequency and profile of the lipid-lowering therapy (LLT) in patients with dyslipidemia (DLP) and cardiometabolic diseases (CMD) in a population sample aged 55-84 years at the current time (2015-2017).Material and methods  Despite guidelines on DLP treatment and the availability of effective and safe lipid-lowering drugs, control of DPL in primary and secondary prevention of cardiovascular diseases (CVD) is insufficient. Knowledge of the level of pharmaceutical correction of DLP in the Russian population is limited; it requires an LLT assessment in various regions and in a wide age range, and a regular monitoring taking into account changing approaches to the correction of DLP. A random population of men and women aged 55-84 years (n=3 896) was evaluated in Novosibirsk in 2015-2017 (project HAPIEE). A joint DLP category was established as low-density lipoprotein cholesterol (LDL-C) ≥3.0 mmol/l, or total cholesterol (TC) ≥5.0 mmol/l, or triglycerides (TG) ≥1.7 mmol/l, or LLT. The combined group of DLP and CMD included ischemic heart disease (IHD), type 2 diabetes mellitus (DM2), and DLP. Regular LLD treatment for the recent 12 months, excluding the dosage of medicines, was assessed using the Anatomic Therapeutic Chemical (ATC) classification. The conditional control of serum lipids was taken as the achievement of LDL-C <3.0 mmol/l, TC <5.0 mmol/l, and TG <1.7 mmol/l.Results In the study sample, the total prevalence of DLP and CMD was 88 % (82.8 % for men and 91.3 % for women, p<0.001). 48.3% of patients in the IHD group, 35.0% in the DM2 group, 29.4% in the DLP group, and 32.8% in the CMD group took LLT. Control of serum lipids was achieved in 18.3% (37.9 % of patients on LLT) of patients with IHD; 9 % (25.6 % of patients on LLT) of patients with DM2; 7.3 % (24.8 % of patients on LLT) of patients with DLP; and 9.0 % (27.6 % of patients on LLTсреди) in the DLP and CMD group. Women with DM2 and DLP more frequently achieved lipid control than men (p<0.001). 98.7 % of study participants took statins as LLT.Conclusion      In the sample of urban population aged 55-84 years in 2015-2017, 90 % of patients had DLP or CMD, and at least ¾ of them required blood lipid control. The lipid control was achieved in every fifth IHD patient and in approximately 40% of those who took LLT. For DM2 or DLP patients, the lipid control was achieved in every tenth patient and in approximately 25% of those receiving LLT. Frequency of lipid control in IHD patients was comparable for men and women; in DM2 and DLP, men less frequently achieved the lipid control than women. About 70% of patients in the combined DLP and CMD group and more than 50% of IHD patients did not take LLT, which considerably contributed to the insufficient lipid control in primary and secondary prevention of atherosclerotic CVDs in this population.

Effects of selected inherited factors on susceptibility to SARS-CoV-2 infection and COVID-19 progression

Genetic predispositions may influence geographical and interethnic differences in COVID-19 prevalence and mortality in affected populations. Of the many genes implicated in COVID-19 progression, a substantial number have no direct functional link on virus transfer/viability or on the host immune system. To address this knowledge deficit, a large number of in silico studies have recently been published. However, the results of these studies often contradict the findings of studies involving real patients. For example, the ACE2 has been shown to play an important role in regulating coronavirus entry into cells, but none of its variations have been directly associated with COVID-19 susceptibility or severity. Consistently was reported that increased risk of COVID-19 is associated with blood group A and with the APOE4 allele. Among other genes with potential impacts are the genes for CCR5, IL-10, CD14, TMPRSS2 and angiotensin-converting enzyme. Variants within the protein-coding genes OAS1 and LZTFL1 (transferred to the human genome from Neanderthals) are understood to be among the strongest predictors of disease severity. The intensive research efforts have helped to identify the genes and polymorphisms that contribute to SARS-CoV-2 infection and COVID-19 severity.

Cardiovascular disease risk factors and cognitive functions in older Russian adults

Background

The prevalence of cardiovascular diseases (CVD) is increasing due to the global trend towards an aging population. CVD and cerebrovascular disease have a negative impact on cognitive health, and CVD risk factors may also be associated with cognitive decline with aging.

Purpose

To investigate associations of modifiable risk factors for CVD with cognitive functions (CF) in older Russian adults.

Methods

A random population sample (3153 men and women, aged 55–84 years) was examined in our city in the 3rd wave of the Russian arm of the international project HAPIEE (Health, Alcohol, and Psychosocial Factors in Eastern Europe). We used standardized epidemiological and instrumental methods for assessment of risk factors, history and treatment of CVD. Cognitive tests included the assessment of memory indicators (immediate and delayed recall), semantic verbal fluency (animal naming), attention, concentration and processing speed (letter cancellation task). Associations between CVD risk factors and cognitive indices were analyzed cross-sectionally.

Results

Mean age in men was of 69.2±7.0 years (n=1198), in women - 69.7±6.9 (n=1955). In both sexes all cognitive domains were positively associated with education and negatively with age (p<0.001 for all cases). In men, after adjusting for health and lifestyle conditions, systolic blood pressure had inverse association with semantic verbal fluency (p=0.015); level of plasma glucose (p=0.003), waist-to-hip ratio (p=0.013) and smoking (p=0.028) were negative associated with letter cancellation task. In multivariate analyses in women, frequency of alcohol consumption (p<0.001 for all CF) and total cholesterol (p=0.042 for memory scores; p=0.001 for letter cancellation task) had positive relationship with CF indices, waist-to-hip ratio (p=0.002 for memory scores, p=0.038 for semantic fluency), level of plasma glucose (p=0.002 for memory scores, p<0.001 for letter cancellation task) and smoking (p<0.001 for letter cancellation task) had inverse relationships with cognition.

Conclusion

Our results show that metabolic risk factors (systolic blood pressure, plasma glucose, waist-to-hip ratio) and smoking had inverse relationship with CF indices in both sexes, and the level of blood lipids (total cholesterol and high-density lipoprotein cholesterol) and frequency of alcohol consumption (more pronounced in women) had positive associations with cognitive domains. These associations were independent from age. In multivariate analyses, some of these correlations were attenuated, and most associations were at least partly mediated by education. These findings highlight the importance of managing CVD risk factors to prevent cognitive decline.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Russian Foundation for Basic Research (20-313-90016),Russian Academy of Sciences (AAAA-A17-117112850280-2)

The frequency and profile of lipid lowering treatment in a contemporary Russian population

Background

Despite of guidelines for management of dyslipidemias (DLP) and the availability of effective and safe lipid lowering drugs (LLD), about one half of CVD patients do not reach the target lipid levels. The knowledge on DLP management in Russian population is limited.

Objective

To analyze the frequency and profile of LLD therapy in subjects with DLP and cardiometabolic diseases in a contemporary Russian population.

Methods

A random population sample of men and women 55–84 years old (n=3898) was examined in 2015–17 in the Russian arm of the HAPIEE project. A composite dysmetabolic group included DLP (total cholesterol, TC ≥5 mmo/l or low-density lipoprotein cholesterol, LDLC ≥3 mmol/l or triglycerides, TG ≥1.7 mmol/l) and/or coronary heart disease (CHD) and/or diabetes mellitus type 2 (DM2). Regular medication intake for 12 months was coded by ATC.

Results

In studied population sample 88% of subjects had dysmetabolic disorders (DLP - 83.1%, CHD - 14.9%, DM2- 20.8%); among them 32.8% subjects received LLD therapy (21.2% in men vs. 39.4% in women, p<0.001) and 17.1% did not report the status of LLD receiving. The frequency of LLD use in CHD group was 48,3%, in DM2 – 35,0%, in DLP – 29.4%. Among named LLD, statins were predominantly used (98%). Lipids control was achieved among subjects with CHD in 18.3% (37.9% among those receiving LLD); among DM2 - in 9.0% (25.6%); among DLP without CHD or DM2 – in 7.3% (24.8%).

Conclusion

In an urban population sample aged 55–84 examined in 2015–17, more than one half of subjects with dysmetabolic disorders (CHD, DM2, DLP) did not receive LLD. Among those receiving lipid-lowering therapy, the lipid control was achieved in about 40% of participants with CHD, and in every forth participant with DM2 or DLP. The lack of lipid control is likely to contribute high rate of atherosclerotic CVD in studied population.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Russian Foundation of Basic Research; Russian Academy of Sciences

The role of connexin 37 polymorphism in spontaneous abortion

Among unique cardiovascular risk factors in women are complications during pregnancy, including miscarriage. Important risk factor is also genetic background. One of powerful candidate genes for cardiovascular disease of atherosclerotic origin (aCVD) is gene for connexin 37 (Cx37) with strong gene-environment interaction including smoking status, that is also strong risk factor for complications in pregnancy including spontaneous abortion (SA). We analyzed association between SA and Cx37 gene polymorphism (1019C>T; Pro319Ser) in 547 fetuses and its potential interaction with smoking status of mothers. Using genetic analyses from women from general population as controls, ORs for T allele, found in our previous studies to be protective against aCVD, were calculated. T allele carriers (fetuses), had OR 0.91 (95 % CI 0.72-1.14) and no interaction with smoking was observed. In conclusion, no significant association between Cx37 polymorphism and SA was observed and no modifying effect of smoking status on this association was detected.

CCR5Delta32 deletion as a protective factor in Czech first-wave COVID-19 subjects

Infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease (COVID-19), has spread widely around the globe. Significant inter-individual differences have been observed during the course of the infection, which suggests that genetic susceptibility may be a contributing factor. CC chemokine receptor 5 (CCR5), which acts as a co-receptor for the entry of HIV-1 into cells, is promising candidate whose can have an influence on SARS-CoV-2 infection. A genetic mutation known as CCR5Delta32, consisting of a 32-nucleotide deletion, encodes a truncated protein that protects homozygous carriers of the deletion from HIV-1 infection. Similarly, inhibition of CCR5 seems to be protective against COVID-19. In our study, we successfully genotyped 416 first-wave SARS-CoV-2-positive infection survivors (164 asymptomatic and 252 symptomatic) for CCR5?32, comparing them with a population based sample of 2,404 subjects. We found the highest number (P=0.03) of CCR5Delta32 carriers in SARS-CoV-2-positive/COVID-19-asympto-matic subjects (23.8 %) and the lowest number in SARS-CoV-2-positive/COVID-19-symptomatic patients (16.7 %), with frequency in the control population in the middle (21.0 %). We conclude that the CCR5?32 I/D polymorphism may have the potential to predict the severity of SARS-CoV-2 infection.

Global DNA methylation in rats´ liver is not affected by hypercholesterolemic diet

Increased plasma cholesterol levels are listed between the major atherosclerosis risk factors. The final plasma cholesterol levels result from the interplay between the genetic and environmental (diet, physical activity) factors. Little is known, how dietary factor influence epigenetics. We have analyzed, if an over-generation feeding of rat with cholesterol influences total liver-DNA methylation, and if total liver-DNA methylation differ between the different rat strains (Prague hereditary hypercholesterolemic rats, Prague hereditary hypertriglyceridemic rats and Wistar Kyoto rats). The animals were feed with high fat (additional 5 % over normal capacity) high cholesterol (2 %) diet for 14 days. DNA methylation in the liver tissue in different generations was analyzed using the liquid chromatography coupled with tandem mass spectrometry. We have not observed any significant changes in total liver-DNA methylation over the 9 generations of animals feed by fat/cholesterol enriched diet. Additionally, there were no differences in DNA methylation between different rat strains. In animal model, the dietary changes (hypercholesterolemic diet) not significantly influence the total DNA methylation status within the liver.

Genetic Markers at ANRIL, FTO and 2q36.3 Locus in Czech Patients Undergoing Coronary Artery Bypass Graft Surgery

Coronary artery bypass graft (CABG) surgery is one of the most commonly performed operations worldwide. We compared genotype frequencies of three major cardiovascular disease (CVD)-associated genetic markers (ANRIL, FTO and 2q36.3 locus) between 753 patients who underwent CABG at the Institute for Clinical and Experimental Medicine (Prague, Czech Republic) and 2,559 controls from the Czech post-MONICA study. Subjects with at least one major A allele in the rs10757274 polymorphism (ANRIL) were more prevalent in patients after CABG than in the controls (81.7 % vs 72.7 %; OR [95 % CI] 1.67 [1.35-2.05]; P < 0.0001). In contrast, variants within the FTO gene (OR 0.87; 95 % CI, 0.70-1. 09 in a TT vs. GG comparison, P = 0.24) and 2q36.3 locus (OR 1.16; 95% CI, 0.98-1.37 in a +A vs. CC comparison, P = 0.08) were not significantly associated with CVD in our study. Variants were not associated with anthropometric, biochemical, or clinical characteristics within the patient group. Our study suggests that patients with CABG are more commonly carriers of some but not all CVD-associated alleles.

Strong Association between APOA5 Gene Polymorphisms and Hypertriglyceridaemic Episodes

Plasma triglyceride (TG) levels represent a significant risk factor of cardiovascular and total mortality. Concentrations of TG in the plasma depend, to a large extent, on the genetic background, and the apolipoprotein A5 (APOA5) gene seems to be one of the most powerful players in the plasma TG metabolism regulation. In total, we analysed three tagging APOA5 (rs964184 rs662799, rs3135506) SNPs in 209 patients with plasma TG levels over 10 mmol/l (HTG) on at least one occasion and in 379 treatment-naïve controls (NTG) with plasma TG values within the normal range. Minor alleles of all three analysed APOA5 polymorphisms significantly (all P < 0.0001) increased the risk of hypertriglyceridaemia. The most significant association (P < 0.0000001) was observed for the rs964184 polymorphism, where the minor GG homozygotes had the odds ratio (OR, 95% CI) for hypertriglyceridaemia development 21.30 (8.09-56.07, P < 0.000001) in comparison with the major CC allele homozygotes. Carriers of at least one minor allele at rs3135506 had OR (95% CI) 4.19 (2.75-6.40); (P < 0.000005) for HTG development and similarly, carriers of a minor allele at rs662799 had OR (95% CI) 3.07 (2.00-4.72) (P < 0.0001). The cumulative presence of risk alleles (unweighted gene score) significantly differed between patients with episodes of high TG and controls at P < 0.0000001. There were 73 % of subjects without any of the risk alleles among the controls and 46 % in the patients. In contrast, the controls just included 3 % of subjects with score 3 and more in comparison with 18 % in HTG patients. We conclude that common APOA5 variants are very important genetic determinants of episodic hypertriglyceridaemia in the Czech population with a high potential to be applied in personalized medicine.

Strong gender-specific additive effects of the NYD-SP18 and FTO variants on BMI values

The role of the FTO gene in obesity development is well established in populations around the world. The NYD-SP18 variant has been suggested to have a similar effect on BMI, but the role of this gene in determining BMI has not yet been verified. The objective of our study was to confirm the association between NYD-SP18 rs6971019 SNP and BMI in the Slavic population and to analyze i) the gender-specific effects of NYD-SP18 on BMI and ii) the simultaneous effect of FTO rs17817449 and NYD-SP18 on BMI. We analyzed a sample of a large adult population based on the post-MONICA study (1,191 males and 1,368 females). Individuals were analyzed three times over 9 years. NYD-SP18 rs6971019 SNP is related to BMI in males (2000/1 GG 28.3+/-3.7 kg/m(2) vs. +A 27.5+/-3.7 kg/m(2) P<0.0005; in other examinations P<0.05 and <0.005), but not in females (all P values over 0.48 in all three examinations). Further analysis revealed the significant additive effect (but not the interaction) of FTO and NYD-SP18 SNPs on BMI in males (all P<0.01). These results suggest that association between NYD-SP18 rs6971019 SNP and BMI may be restricted to males. Furthermore, variants within NYD-SP18 and FTO genes revealed a significant additive effect on BMI values in males.

Genetic predisposition of human plasma triglyceride concentrations

The issue of plasma triglyceride levels relative to the risk of development of cardiovascular disease, as well as overall mortality, has been actively discussed for many years. Like other cardiovascular disease risk factors, final plasma TG values have environmental influences (primarily dietary habits, physical activity, and smoking), and a genetic predisposition. Rare mutations (mainly in the lipoprotein lipase and apolipoprotein C2) along with common polymorphisms (within apolipoprotein A5, glucokinase regulatory protein, apolipoprotein B, apolipo-protein E, cAMP responsive element binding protein 3-like 3, glycosylphosphatidylinositol-anchored HDL-binding protein 1) play an important role in determining plasma TG levels.

Comparison of the relative telomere length measured in leukocytes and eleven different human tissues

The relative length of telomeres measured in peripheral blood leukocytes is a commonly used system marker for biological aging and can also be used as a biomarker of cardiovascular aging. However, to what extent the telomere length in peripheral leukocytes reflects telomere length in different organ tissues is still unclear. Therefore, we have measured relative telomere length (rTL) in twelve different human tissues (peripheral blood leukocytes, liver, kidney, heart, spleen, brain, skin, triceps, tongue mucosa, intercostal skeletal muscle, subcutaneous fat, and abdominal fat) from twelve cadavers (age range of 29 week of gestation to 88 years old). The highest rTL variability was observed in peripheral leukocytes, and the lowest variability was found in brain. We found a significant linear correlation between leukocyte rTL and both intercostal muscle (R=0.68, P<0.02) and liver rTL (R=0.60, P<0.05) only. High rTL variability was observed between different organs from one individual. Furthermore, we have shown that even slight DNA degradation (modeled by sonication of genomic DNA) leads to false rTL shortening. We conclude that the rTL in peripheral leukocytes is not strongly correlated with the rTL in different organs.

Statin-associated myopathy: from genetic predisposition to clinical management

Statin-associated myopathy (SAM) represents a broad spectrum of disorders from insignificant myalgia to fatal rhabdomyolysis. Its frequency ranges from 1-5 % in clinical trials to 15-20 % in everyday clinical practice. To a large extent, these variations can be explained by the definition used. Thus, we propose a scoring system to classify statin-induced myopathy according to clinical and biochemical criteria as 1) possible, 2) probable or 3) definite. The etiology of this disorder remains poorly understood. Most probably, an underlying genetic cause is necessary for overt SAM to develop. Variants in a few gene groups that encode proteins involved in: i) statin metabolism and distribution (e.g. membrane transporters and enzymes; OATP1B1, ABCA1, MRP, CYP3A4), ii) coenzyme Q10 production (e.g. COQ10A and B), iii) energy metabolism of muscle tissue (e.g. PYGM, GAA, CPT2) and several others have been proposed as candidates which can predispose to SAM. Pharmacological properties of individual statin molecules (e.g. lipophilicity, excretion pathways) and patients´ characteristics influence the likelihood of SAM development. This review summarizes current data as well as our own results.

Rs6922269 marker at the MTHFD1L gene predict cardiovascular mortality in males after acute coronary syndrome

Myocardial infarction (MI) is the leading cause of death in industrialized countries. All the traditional risk factors for MI are responsible for approximately 50% of cases of MI cases. Attention therefore has recently focused on genetic variants that are not associated with conventional risk factors. One of them is the marker rs6922269, which has been suggested as a risk factor for development of MI in Western populations. We analyzed the relationship between rs6922269 variant on MTHFD1L gene and (i) risk of the acute coronary syndrome (ACS) in the Czech population and (ii) mortality in 7 years follow up. Rs6922269 (G>A) variant was analyzed (CR 99.3% for patients and 98.0% for controls) by PCR-RFLP in consecutively examined 1614 men and 503 women with ACS (age below 65 years) and in population-based controls--1191 men and 1368 women (aged up to 65 years). ANOVA and Chi square were used for statistical analysis. The genotype frequencies were almost identical (P=0.87) in the ACS patients and in controls and no differences were observed, if males (P=0.73) and females (P=0.93) were analysed separately. In addition, rs6922269 polymorphism was not associated with the classical risk factors (dyslipidemia, hypertension, obesity, smoking, diabetes) in control population. Cardiovascular mortality was significantly higher in males, carriers of the AA genotype (P<0.001, OR 2.52, 95% CI 1.40-4.55, for AA vs. +G). We conclude, that rs6922269 variant at MTHFD1L gene could be an important prognostic factor for cardiovascular mortality in patients after ACS.

The association between APOA5 haplotypes and plasma lipids is not modified by energy or fat intake: the Czech HAPIEE study

BACKGROUND AND AIMS

Several smaller studies reported interactions between dietary factors and apolipoprotein A5 (APOA5) gene polymorphisms in determination of plasma lipids. We tested interactions between APOA5 haplotypes and dietary intake in determination of plasma triglycerides (TG) and other lipids.

METHODS AND RESULTS

Participants (5487 males and females aged 45-69) were classified according to the number (0, 1, 2+) of minor APOA5 alleles (using T-1131 > C; rs662799 and Ser19 > Trp; rs3135506 polymorphisms) and into three groups of low (bottom 25%), medium (26th-75th percentile) and high (top 25%) of intake of total energy and total, saturated and polyunsaturated fats, assessed by food frequency questionnaire. The age-sex adjusted geometric means of plasma TG increased with the number of minor alleles, from 1.57 (standard error 0.01), to 1.79 (0.02) to 2.29 (0.10) mmol/L (p < 0.00001) but TG did not differ between groups with low, medium and high total energy intake (p = 0.251). TG concentrations were highest in subjects with the combination of 2+ minor alleles and the highest energy intake (mean 2.59 [0.19], compared with 1.62 [0.03] in subjects with lowest energy intake and no minor allele) but the interaction between energy intake and APOA5 haplotypes was not statistically significant (p = 0.186). Analogous analyses with total, saturated and polyunsaturated fat intake yielded similar nonsignificant results. Effects of APOA5 and dietary intakes on total and HDL cholesterol were weaker and no interactions were significant.

CONCLUSION

In this Slavic Caucasian population sample, we did not detect the hypothesized interaction between common SNPs within the APOA5 gene and diet in determination of blood lipids.

Association between FTO 1st intron tagging variant and telomere length in middle aged females. 3PMFs study

The FTO gene plays an important role in the determination of body weight and BMI and it has been suspected of being associated with all-cause mortality, cardiovascular disease, cancer and end stage renal disease, but the causal mechanism of these effects is still unknown. One of the possibilities is the potential association with telomere length. Telomeres are repetitive DNA-sequences located at the ends of eukaryotic chromosomes' length of which is reduced in all somatic cells during ageing. Out of the 908 females (3PMFs study), in 783 females both FTO 1st intron tagging polymorphism (G>T, rs17817449) and the relative telomere length were successfully analysed. The relative telomere length was calculated as the ratio of telomere repeats to single-copy gene copies. The frequencies of the FTO genotypes were similar to other populations (GG=18.3%, GT=49.1% and TT=32.6%). We have detected, that the relative telomere length was significantly shorter (P<0.02, P<0.01 after adjustment for age, BMI, waist and subcutaneous fat), in carriers of at least one FTO risky (G) allele (0.85±0.39) in comparison to the carriers of the protective TT genotype (0.93±0.48). We have demonstrated that the FTO variant could be associated with the relative telomere length. Whether this represents a causality of association between the FTO variant and the non-communicable diseases needs to be further analysed.

No relation between angiotensin‐converting enzyme gene polymorphism and smoking dependence

BACKGROUND

Smoking as a major risk factor for development of cancer and cardiovascular disease is thought to be partially genetically determined. The aim of this study was to investigate whether there is an association between insertion/deletion (I/D) polymorphism in angiotensin-converting enzyme (ACE) and smoking status and the number of cigarettes smoked per week.

METHODS

Using polymerase chain reaction, I/D polymorphism was evaluated in the ACE gene in 1204 male and 1375 female representative Caucasians. Information about smoking status and number of cigarettes smoked per week was collected via a questionnaire.

RESULTS

Frequencies of the alleles and genotypes of ACE I/D polymorphism did not differ between smokers, past smokers and individuals who had never smoked. No association was found between ACE I/D polymorphism and the number of cigarettes smoked per week, either in males or in females.

CONCLUSION

I/D polymorphism in the ACE gene does not play any role in genetic determination of predisposition to smoking.

High prevalence of microchimerism in female patients

Evaluation of free plasma DNA has been suggested as one of the option to detect organ rejection in transplanted patients. However, the presence of chimeric cells in organs could make this approach complicated. To study the presence of Y-chromosome chimeric cells, we examined biopsy samples of 40 thoracic aortas of female donors and recipients. Using nested polymerase chain reaction, the presence of Y-chromosome-specific DNA sequences was detected in 19 (47.5%) analyzed tissue samples. Thus, free DNA originating from more than two genomes could be present in plasma in such a high proportion of cases. This phenomenon makes the use of plasma free DNA for the detection of organ rejection difficult and impractical.

Changes of plasma lipids during weight reduction in females depends on APOA5 variants

BACKGROUND

Apolipoprotein A5 (APOA5) is a determinant of plasma lipids, and its role in body mass index (BMI) determination is discussed. This study was aimed at the investigation of the relationship between common APOA5 gene variants and body weight/plasma lipid decrease in overweight females.

METHODS

We analyzed 98 unrelated overweight and obese nondiabetic Czech females (BMI >27.5). APOA5 T-1131-->C and Ser19-->Trp variants were genotyped. Before and after 9 weeks of lifestyle modification, biochemical and anthropometrical measurements and assessment of nutritional intake were performed. The lifestyle modification program consisted of a reduction in energy intake and an exercise program (aerobic exercise 4 times per week, 60 min each).

RESULTS

The mean age of the participants was 30.7 +/- 3.7 years, the mean BMI before the intervention was 31.4 +/- 3.8 and the weight loss was 5.9 +/- 2.5 kg (7 +/- 3%). There were 86 T-1131T homozygotes and 12 carriers of the C-1131 allele and 82 Ser19Ser homozygotes and 16 carriers of the Trp19 allele, respectively; 72 females had the commonest T-1131T/Ser19Ser haplotype. No significant association between BMI decrease and APOA5 variants was found, but T-1131T carriers have a significantly higher body weight both before and after the intervention (p < 0.05; p = not significant for BMI). The fasting glycemia was significantly higher in Trp19 carriers both before and after the intervention (p < 0.01). Further, plasma triglyceride levels decreased in Ser19Ser homozygotes but increased in Trp19 carriers (1.42 +/- 0.62 to 1.28 +/- 0.48 vs. 1.15 +/- 0.47 to 1.41 +/- 0.80 mmol/l; p < 0.05 for differences between the groups). Similarly, in carriers of at least 1 less common APOA5 allele (n = 26), plasma low-density lipoprotein cholesterol levels did not decrease as they did in T-1131T/Ser19Ser carriers (3.11 +/- 0.70 to 3.27 +/- 0.81 vs. 3.39 +/- 0.81 to 3.16 +/- 0.86 mmol/l; p < 0.05 for differences between the groups).

CONCLUSIONS

APOA5 gene variants have effects on the decrease in plasma triglyceride and low-density lipoprotein cholesterol level in females in a model combining their dietary habits and physical activity changes.

Effects of six APOA5 variants, identified in patients with severe hypertriglyceridemia, on in vitro lipoprotein lipase activity and receptor binding

OBJECTIVE

The purpose of this study was to identify rare APOA5 variants in 130 severe hypertriglyceridemic patients by sequencing, and to test their functionality, since no patient recall was possible.

METHODS AND RESULTS

We studied the impact in vitro on LPL activity and receptor binding of 3 novel heterozygous variants, apoAV-E255G, -G271C, and -H321L, together with the previously reported -G185C, -Q139X, -Q148X, and a novel construct -Delta139 to 147. Using VLDL as a TG-source, compared to wild type, apoAV-G255, -L321 and -C185 showed reduced LPL activation (-25% [P=0.005], -36% [P<0.0001], and -23% [P=0.02]), respectively). ApoAV-C271, -X139, -X148, and Delta139 to 147 had little affect on LPL activity, but apoAV-X139, -X148, and -C271 showed no binding to LDL-family receptors, LR8 or LRP1. Although the G271C proband carried no LPL and APOC2 mutations, the H321L carrier was heterozygous for LPL P207L. The E255G carrier was homozygous for LPL W86G, yet only experienced severe hypertriglyceridemia when pregnant.

CONCLUSIONS

The in vitro determined function of these apoAV variants only partly explains the high TG levels seen in carriers. Their occurrence in the homozygous state, coinheritance of LPL variants or common APOA5 TG-raising variant in trans, appears to be essential for their phenotypic expression.

Detection of Donor DNA After Heart Transplantation: How Far Could It Be Affected by Blood Transfusion and Donor Chimerism?

The possibility to detect donor DNA in recipient plasma has been discussed as a method to prove organ rejection without a biopsy. Usually, the presence of Y chromosome-specific DNA sequences in female recipients has been used as an example. We have analyzed the presence of part of Y chromosomes in females after heart transplantation. The results suggested that pretransplantation blood transfusion together with cell chimerism of donor organs could be factors that affect detection of donor DNA in recipient plasma. Among females who have undergone transplantation, if the donor organ is chimeric, nested polymerase chain reaction may permit detection of Y chromosome-specific DNA sequences to estimate rejection. In other cases, extremely well-controlled methods using multiple markers need to be developed to avoid the danger of false-positive or false-negative results.

APOA5 variant Ser19Trp influences a decrease of the total cholesterol in a male 8 year cohort

OBJECTIVES

To evaluate whether the relationship between dietary composition and plasma lipid levels is genetically determined.

DESIGN AND METHODS

We have evaluated the influence of common apolipoprotein A5 (APOA5) variants (T-1131 > C, Ser19 > Trp and Val153 > Met) on plasma lipid concentrations in 117 males for whom dietary composition markedly changed and total cholesterol decreased (from 6.21 +/- 1.31 mmol/L in 1988 to 5.43 +/- 1.06 mmol/L in 1996) over an 8 year follow-up study.

RESULTS

APOA5 T-1131 > C and Val153 > Met variants did not influence the change in lipid measures over time. In Ser/Ser19 homozygotes, the plasma cholesterol was relatively stable over the years (6.1 +/- 1.2 mmol/L in 1988 and 5.6 +/- 1.0 mmol/L in 1996, -8%, P < 0.01). In contrast, in the Trp19 carriers, the decrease of the plasma cholesterol was more than 20% (6.5 +/- 1.6 mmol/L in 1988 and 5.1 +/- 1.0 mmol/L in 1996) (P < 0.001). The difference of the changes is significant (8% vs. 20%, P < 0.005). Changes in other analyzed lipid parameters have not been significantly associated with APOA5 variants.

CONCLUSIONS

Ser19 > Trp variant in the APOA5 gene may play an important role in an individual's sensitivity to dietary composition.

The influence of APOAV polymorphisms (T-1131>C and S19>W) on plasma triglyceride levels and risk of myocardial infarction

The importance of an APOAV gene for plasma triglyceride level determination has been shown on transgenic and knockout mice. We examined whether APOAV variants are associated with plasma triglyceride levels and risk of myocardial infarction (MI). We have evaluated the influence of APOAV polymorphisms (T-1131>C and S19>W) on plasma triglycerides in 1191 males and 1368 females representatively selected from the Czech population. Triglycerides have been analysed in 1997 and 2001. Subsequently, we have analysed the genotype frequencies of the APOAV polymorphism in 435 patients with MI. T-1131>C variation in the APOAV gene affects the plasma triglyceride showing a higher level in C-1131 carriers than in T/T-1131 homozygotes. This association has been observed both in males and females (p < 0.001). Similarly, plasma triglycerides were also significantly influenced by the S19>W APOAV genotypes. In both males and females, the W19 carriers have triglycerides significantly (p < 0.001) higher compared to the S19 homozygotes. In a group of MI patients, the frequency of the rare homozygotes for at least one APOAV polymorphism (C/C-1131 and/or W/W19) was significantly higher than that in the population sample (7.4 vs 2.0%, p < 0.00001). We conclude that variations in the APOAV gene not only play a role in genetic determination of triglyceride levels but also could influence risk of MI.

Rare variant of apolipoprotein E (Arg136-->Cys) in a subject with normal lipid values

During the screening of apolipoprotein (apo) E gene polymorphism with PCR and subsequent restriction analysis, we have identified a female carrier with a mutant allele Arg136-->Cys. This proband had normal lipid parameters and no history of coronary artery disease (CAD). We did not confirm the previously described connection between apo E Arg136-->Cys mutation and elevated lipid levels. In the case of this mutation, other factors (environmental and/or genetic) are important for the development of lipid metabolism disorders.

An apolipoprotein influencing triglycerides in humans and mice revealed by comparative sequencing

Comparison of genomic DNA sequences from human and mouse revealed a new apolipoprotein (APO) gene (APOAV) located proximal to the well-characterized APOAI/CIII/AIV gene cluster on human 11q23. Mice expressing a human APOAV transgene showed a decrease in plasma triglyceride concentrations to one-third of those in control mice; conversely, knockout mice lacking Apoav had four times as much plasma triglycerides as controls. In humans, single nucleotide polymorphisms (SNPs) across the APOAV locus were found to be significantly associated with plasma triglyceride levels in two independent studies. These findings indicate that APOAV is an important determinant of plasma triglyceride levels, a major risk factor for coronary artery disease.

Mutations in ATP-cassette binding proteins G5 (ABCG5) and G8 (ABCG8) causing sitosterolemia

Sitosterolemia is an autosomal recessive disorder caused by mutations in two adjacent genes encoding coordinately regulated ATP binding cassette (ABC) half transporters (ABCG5 and ABCG8). In this paper we describe three novel mutations causing sitosterolemia: 1) a frameshift mutation (c.336-337insA) in ABCG5 that results in premature termination of the protein at amino acid 197; 2) a missense mutation that changes a conserved residue c.1311C>G; N437K) in ABCG5 and 3) a splice site mutation in ABCG8 (IVS1-2A>G). This study expands the spectrum of the ABCG5 and ABCG8 mutations that cause sitosterolemia. Nine nonsynonymous polymorphisms are also reported: I523V, C600Y, Q604E, and M622V in ABCG5; and D19H, Y54C, T400K, A632V, and Y641F in ABCG8.

A possible role of apolipoprotein E polymorphism in predisposition to higher education

A potential candidate gene that could contribute to the education process is the apolipoprotein E (apo E) gene that has been shown to correlate with memory function and memory decline. We measured apo E polymorphism in groups of probands with different levels of education selected from a population sample. In the group of probands with higher education (n = 82), 24.4% had the e4 allele, compared with 7.3% who had the e2 allele. A reverse association was found in the group that left school aged 15 (n = 36) - 8.3% had the e4 allele and 13.9% had the e2 allele. Eighty-seven percent of the probands with the allele e4 reached higher education, compared to only 54.5% with the allele e2. The difference between the groups is statistically significant (p = 0.039), and this may indicate some role for the apo E polymorphism in subjects' intelligence or ability to learn.

Association between apolipoprotein B promotor haplotypes and cholesterol status

Association between apolipoprotein B (apo B) promoter haplotypes and cholesterol concentration was studied in two groups of children with low and high concentrations of cholesterol. Strong linkage equilibrium was demonstrated between I/D in the signal peptide of apo B and (C-516T) polymorphism in the promotor of apo B gene, and the I/I+ allele T haplotype was associated with a low cholesterol concentration.

Genetic determination of plasma lipids and insulin in the Czech population

OBJECTIVES

To evaluate the association between plasma lipids and insulin and variation in the genes for apolipoproteins (APO) E (CfoI), B (insertion/deletion), C1 (HpaI), and C3 (C-482T, C3238G) in a population-based Czech Slavonic study.

DESIGN AND METHODS

In 131 men and 154 women, polymorphisms were investigated using PCR. In the same subjects plasma lipid levels and insulin were measured.

RESULTS

In the women, carriers of the e4 allele had higher apoB (p = 0.03) and triglyceride (p = 0.03) compared to e3 homozygotes, whereas in the men, the effect of the e4 allele was seen on total cholesterol (p = 0.02), LDL cholesterol (p = 0.003) and apoB (p = 0.001). Compared with SP27 (insertion) homozygotes of the APOB polymorphism, women SP24 (deletion) homozygotes had higher levels of total (p = 0.003) and LDL cholesterol (p = 0.007) and apoB (p = 0.05). No significant effect was seen in the men. Women homozygous for the APOC3 -482T allele had higher insulin levels than -482C homozygotes (p = 0.03). Men homozygous for APOC3 -482T allele have the highest plasma triglyceride level (p = 0.02). The APOC1 polymorphism exhibited no significant effect on any of the parameters studied.

CONCLUSIONS

In this sample, variation at the APOE, APOB and APOC3 genes play a role in determining plasma levels of insulin and lipids, and emphasize the importance of gender-associated effects in the genetic determinations.

Gene variants of the bactericidal/permeability increasing protein and lipopolysaccharide binding protein in sepsis patients

OBJECTIVES

To determine whether the genotype frequencies of the five bi-allelic polymorphisms in the bactericidal/permeability increasing protein (BPI) (Lys216 --> Glu; PstI polymorphism in intron 5; silent mutation G545 --> C) and the lipopolysaccharide binding protein (LBP) (Cys98 --> Gly; Pro436 --> Leu) are associated with the incidence and lethality of sepsis.

DESIGN

Case control study of patients with sepsis.

SETTING

Intensive care units within university hospitals.

PATIENTS

A total of 204 patients diagnosed with sepsis and 250 healthy blood donors.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Short DNA fragments containing the polymorphic sites of the LBP and BPI locus were amplified by the polymerase chain reaction or mismatched polymerase chain reaction. The individual polymorphisms were determined with the appropriate restriction enzyme digestions and subsequent agarose gel electrophoresis. The presence of LBP genotypes with the less frequent Gly98 allele was found to be associated with sepsis (p < .02) in male patients, but not in females. Patients which were homozygote for either of the rare Gly98 (n = 6) and/or Leu436 (n = 5) LBP alleles, furthermore, exclusively were nonsurvivors of sepsis. The genotype frequencies in the BPI gene did not differ between patients and control individuals.

CONCLUSIONS

Our findings suggest that common polymorphisms in the gene for LBP in combination with male gender are associated with an increased risk for the development of sepsis and, furthermore, may be linked to an unfavorable outcome. These data support the important immunomodulatory role of LBP in Gram-negative sepsis and suggest that genetic testing may be helpful for the identification of patients with an unfavorable response to Gram-negative infection.

The common functional C(-159)T polymorphism within the promoter region of the lipopolysaccharide receptor CD14 is not associated with sepsis development or mortality

Sepsis is characterised by a systemic inflammatory response to bacterial products during infection, which interestingly both in humans and animal models is gender associated with a higher susceptibility of males than females. The CD14 receptor is involved in activation of cells by lipopolysaccharides released from Gram-negative bacteria and, as recently shown, also by products of Gram-positive bacteria (e.g., peptidoglycans and lipoteichoic acid). The functional relevance of a C(-159)T CD14 polymorphism recently has been shown based on correlation of the T allele to higher plasma levels of soluble CD14, and higher membrane expression on monocytes. We, therefore, now analysed this CD14 polymorphism in 204 patients with severe sepsis and 247 controls. No significant difference of allele frequencies was observed between sepsis patients and controls neither for males nor females. Mortality also was not associated with the polymorphism studied. This may suggest that other mechanisms for lipopolysaccharide recognition, such as the recently described Toll-like receptors are important for inflammatory cell activation in sepsis.

Plasma levels of remnant particles are determined in part by variation in the APOC3 gene insulin response element and the APOCI-APOE cluster

Remnant particles of triglyceride-rich lipoproteins (RLP) are known to be a strong predictor of atherogenicity. The serum concentrations of remnant-like particle triglyceride (RLPTG) and remnant-like particle cholesterol (RLPC) have been determined in a representative sample of the Czech MONICA study (n = 285). The relationship was investigated between remnant particle triglyceride/cholesterol concentrations and polymorphisms in the genes APOC3 (-482C-->T/3238C-->G), APOE (epsilon2/epsilon3/epsilon4), APOCI (-317-321ins), APOB (signal peptide), hepatic lipase (LIPE, -480C-->T), and lipoprotein lipase (LPL, S447X). Univariate analysis showed significant effects on RLPTG associated only with the APOE genotype (P = 0.009), the APOC3 -482C-->T genotype (P = 0.018), and the APOCI -317-321ins (P = 0.014) genotype and significant effects on RLPC with APOE (P = 0.01) and APOCI -317-321ins (P = 0.021). The raising effect of the APOE genotype for both remnant cholesterol and triglyceride was confined to the epsilon2/4 (n = 6) and varepsilon4/4 (n = 3) groups, and thus when the epsilon2/4 group was omitted in order to analyze by allele (epsilon2+/epsilon3+/epsilon4+), significance was lost (P = 0.6). There was strong linkage disequilibrium between the APOE and APOCI alleles (chi(2), P < 0.001) and a multivariate ANOVA of RLPTG with all three significantly associated variants as factors demonstrated that while the APOC3 -482C-->T effect was independent of the others (P = 0.003), the APOCI -317-321ins and APOE effects were not. This was also true for the APOCI -317-321ins and APOE effects on RLPC. To assess whether APOE-CI effects on RLPC were independent of their effects on total cholesterol and triglyceride levels, multiple linear regression was used. Using multiple linear regression, it appeared that the APOE-CI effects on RLPC were independent of their effects on plasma cholesterol, but the effects of APOC3 and APOE-CI on RLPTG could not be separated from their effects on plasma Tg levels. Further characterization of this remnant particle phenotype and its genetic determinants may lead to a better understanding of its metabolism and contribution to atherosclerosis.

Alternative method for diagnosis of two polymorphisms in the human transforming growth factor-beta1 by PCR-mediated double site-directed mutagenesis

Cytokine transforming growth factor-beta1 plays an important role in physiological processes during ontogenesis, cell differentiation, immune responses, carcinogenesis, inflammation, wound healing, fibroproduction, progression of renal insufficiency and arteriosclerotic lesion development. Its biological function is influenced through the two signal peptide polymorphisms. We describe a new, economical, easy and fast alternative method which allows detection of both polymorphisms from one PCR product with subsequent restriction analysis with two different restriction enzymes. This method could facilitate further research on the role of this cytokine in human disease.

Insertion/deletion polymorphism in the angiotensin-converting enzyme gene in myocardial infarction survivors

INTRODUCTION

Insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene influenced the plasma concentration of the ACE, and is D allele have been repetitively suggested as a risk factor for myocardial infarction (MI).

MATERIAL AND METHODS

Two hundert thirty six male myocardial infarction survivors under 65 years and with body mass index and total plasma cholesterol levels under 95% of the Czech population were included in the study. As control group, 302 male controls (1% randomly selected group from the Czech population) were genotyped. I/D polymorphism in the ACE gene was determined using polymerase chain reaction.

RESULTS

The prevalence of the I/I, I/D and D/D genotypes was 0.218, 0.494 and 0.288, in the control group, and 0.178, 0.538 and 0.284, in the myocardial survivors, respectively. The male Czech population has the similar frequency of insertion and deletion alleles compared to other Caucasian populations. The frequencies of the alleles and genotypes of the ACE gene did not differ significantly between MI survivors and a control sample of the Czech population.

CONCLUSION

It was shown that the I/D polymorphism in the gene for ACE is not a genetic risk factor for myocardial infarction in the Czech population.

(TTA)n repeat polymorphism in the HMG-CoA reductase gene and cholesterolaemia

BACKGROUND

Hypercholesterolaemia is one of the main risk factors of atherosclerosis. Both environmental and genetic factors have been implicated in the development of hypercholesterolaemia. The enzyme hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase plays an important role in cholesterol synthesis. Thus we supposed that polymorphisms in this gene could influence cholesterolaemia.

PATIENTS AND METHODS

Using PCR, we measured the (TTA)n repeat polymorphism near the Alu sequence of the gene for HMG-CoA reductase in two groups of children selected from opposite ends of the cholesterolaemia distribution curve obtained from measuring cholesterolaemia in 2000 children. Eighty-two children in high- and eighty-six children in low-cholesterolaemic groups participated on the study.

RESULTS

A significant difference was found in the frequencies of the genotypes of the 10+ add alleles (43.9% in high-cholesterolaemic children vs 24.4% in low-cholesterolaemic children p < 0.025). No differences were demonstrated in the frequencies of other genotypes (allele 10+ even and without allele 10). No associations between lipid parameters and genotypes or genotype subgroups within the group of high- and low-cholesterolaemic children were found.

CONCLUSION

The (TTA)n repeat polymorphism in the gene for HMG-CoA reductase could be another genetic marker that plays a role in the genetic determination of cholesterolaemia.