Myocardial Infarction Susceptibility and the MTNR1B Polymorphisms.

Melatonin is a circadian hormone with antioxidant properties that protects against myocardial ischemia-reperfusion injury. Genetic variations of the melatonin receptor 1B gene (MTNR1B) play an important role in the development of type 2 diabetes, a risk factor for cardiovascular diseases. Accordingly, MTNR1B polymorphisms are crucial in numerous disorders of the cardiovascular system. Therefore, the aim of the present study was to investigate a possible association of MTNR1B polymorphisms with chronotype and susceptibility to myocardial infarction. The present case-control study included 199 patients with myocardial infarction (MI) (57% men) and 198 control participants (52% men) without previous cardiovascular diseases who underwent genotyping for the MTNR1B polymorphisms rs10830963, rs1387153, and rs4753426 from peripheral blood samples. Chronotype was determined using the Morningness-Eveningness Questionnaire (MEQ). As estimated by the chi-square test, no significant association was found in the distribution of alleles and genotypes between myocardial infarction patients and controls. In addition, there was no association between MTNR1B polymorphisms and chronotype in MI patients. As some previous studies have shown, the present negative results do not exclude the role of the MTNR1B polymorphisms studied in the development of myocardial infarction. Rather, they may indicate that MTNR1B polymorphisms are a minor risk factor for myocardial infarction.

The Association between Circadian Clock Gene Polymorphisms and Metabolic Syndrome: A Systematic Review and Meta-Analysis.

Metabolic syndrome (MetS) is a combination of cardiovascular risk factors associated with type 2 diabetes, obesity, and cardiovascular diseases. The circadian clock gene polymorphisms are very likely to participate in metabolic syndrome genesis and development. However, research findings of the association between circadian rhythm gene polymorphisms and MetS and its comorbidities are not consistent. In this study, a review of the association of circadian clock gene polymorphisms with overall MetS risk was performed. In addition, a meta-analysis was performed to clarify the association between circadian clock gene polymorphisms and MetS susceptibility based on available data. The PubMed and Scopus databases were searched for studies reporting the association between circadian rhythm gene polymorphisms (ARNTL, BMAL1, CLOCK, CRY, PER, NPAS2, REV-ERBα, REV-ERBß, and RORα) and MetS, and its comorbidities diabetes, obesity, and hypertension. Thirteen independent studies were analyzed with 17,381 subjects in total. The results revealed that the BMAL1 rs7950226 polymorphism was associated with an increased risk of MetS in the overall population. In contrast, the CLOCK rs1801260 and rs6850524 polymorphisms were not associated with MetS. This study suggests that some circadian rhythm gene polymorphisms might be associated with MetS in different populations and potentially used as predictive biomarkers for MetS.

Identification of human remains from the Second World War mass graves uncovered in Bosnia and Herzegovina.

AIM: To present the results obtained in the identification of human remains from World War II found in two mass graves in Ljubuski, Bosnia and Herzegovina. METHODS: Samples from 10 skeletal remains were collected. Teeth and femoral fragments were collected from 9 skeletons and only a femoral fragment from 1 skeleton. DNA was isolated from bone and teeth samples using an optimized phenol/chloroform DNA extraction procedure. All samples required a pre-extraction decalcification with EDTA and additional post-extraction DNA purification using filter columns. Additionally, DNA from 12 reference samples (buccal swabs from potential living relatives) was extracted using the Qiagen DNA extraction method. QuantifilerTM Human DNA Quantification Kit was used for DNA quantification. PowerPlex ESI kit was used to simultaneously amplify 15 autosomal short tandem repeat (STR) loci, and PowerPlex Y23 was used to amplify 23 Y chromosomal STR loci. Matching probabilities were estimated using a standard statistical approach. RESULTS: A total of 10 samples were processed, 9 teeth and 1 femoral fragment. Nine of 10 samples were profiled using autosomal STR loci, which resulted in useful DNA profiles for 9 skeletal remains. A comparison of established victims' profiles against a reference sample database yielded 6 positive identifications. CONCLUSION: DNA analysis may efficiently contribute to the identification of remains even seven decades after the end of the World War II. The significant percentage of positively identified remains (60%), even when the number of the examined possible living relatives was relatively small (only 12), proved the importance of cooperation with the members of the local community, who helped to identify the closest missing persons' relatives and collect referent samples from them.

Most common HCV genotypes in patients from north-eastern Croatia.

OBJECTIVE: The aims of this study were to determine the HCV-RNA viral load, genotype distribution, risk factors and symptoms of HCVRNA positive viral load in HCV antibody-positive patients from north-eastern Croatia. MATERIALS AND METHODS: From January 2009 to December 2011, 203 HCV antibody- positive patients (130 men and 73 women; median age 44.5 years) were analyzed for HCV-RNA by the COBAS TaqMan HCV test and genotyped by the Linear Array HCV Genotyping test (both from Roche). All patients completed a structured questionnaire about risk factors and symptoms. RESULTS: The HCV-RNA percentage was 61.1% and was similar for men and women. The HCV-RNA viral load increased with age: while 55% of 20-50 year old patients were HCV-RNA positive, 73% of patients >50 years were positive (p=0.021). Genotype 1 was the most prevalent genotype (79.8%), followed by 3 (12.9%), 4 (6.5%), and 2 (0.8%); genotypes 5 and 6 were not determined. Patients with genotype 1 (median, 50 years) were older than patients with 3 (median, 33.5 years) or 4 (median, 38 years). The blood transfusions performed in Croatian hospitals before 1993 was significantly associated with HCV-RNA positive viral load (p<0.05). CONCLUSION: These data indicated an elevated prevalence of genotype 1 in elderly HCV-RNA positive patients and it may continue to rise. Using RNA-based detection in HCV positive-antibody patients would allow early detection of HCV in the acute stage of HCV disease and the increased risk of HCV genotyperelated treatment failure.

Prevalence and genotype distribution of high-risk human papillomavirus (HR HPV) in male genital samples of Osijek-Baranja County.

This is a first cross-sectional study on the prevalence and distribution of HPV infection in asymptomatic, heterosexual men from Osijek-Baranja County, Croatia. Between 2009 and 2011, 330 men tested for sexually transmitted diseases (STDs) were recruited. Their genital swabs were tested for high-risk HPV (HR HPV) infection by the AMPLICOR HPV test and further genotyped by the Linear Array HPV Genotyping Test (both by Roche). Infection with a single HR HPV was detected in almost one third of men (39%) whereas multiple HPV types, in more than a half of HR HPV-positive men (61%). The highest HR HPV prevalence was detected in those younger than 20 (37.5%) and lowest in 31-35 year old men (27.8%). The most common genotypes were HPV 6 (24%), 16 (17.8%), 51 (9%), 52 (6%), 35, 55, 66, 84 (each 5%), 31, 62 (each 4%), 39, 58, 59, 83 (each 2.5%), and finally 56, 18, 53, and 54 (each 1.3%). Having more than one sexual partner per year was significantly associated with HR HPV infection in age group between 26 and 30 years (p = 0.001). Due to the high prevalence of HR HPV infection in men of this County and its risk of transmission to women, we recommend more public awareness about this particular STD and initiating vaccination programs of young men and women.

Distribution of Chlamydia trachomatis serotypes in clinical urogenital samples from north-eastern Croatia.

The purpose of this study was to determine prevalence of Chlamydia trachomatis (Ct) urogenital infection and its serotype distribution from clinical samples in north-eastern Croatia. During a 3-year period, 2,379 urogenital samples were analyzed by real-time polymerase chain reaction (A group), while 4,846 genital swabs were analyzed by direct fluorescent antibody test (B group). 132 Ct positive specimens were genotyped by omp1 gene sequencing. The prevalence rate of Ct was 3.2 % in A and 1 % in B group. The most prevalent chlamydial genotype was E (44 %), followed by F (33 %), K (11.5 %), G (8 %), J/UW (5.3 %), D-IC (4.4 %), D-B120 (1.8 %), and B/IU, J/IU, Ia/IU (0.9 % each) serotypes. Single-nucleotide polymorphisms (SNPs) of omp1 gene were detected in E, K, and G serotypes. Some of these SNPs (C/T at position 272 and G/A at position 813 in E strain; C/T at position 884 in D strain) might represent novel omp1 variants.

Association of nephrolithiasis and gene for glucose transporter type 9 (SLC2A9): study of 145 patients.

AIM: To investigate the association of nephrolithiasis and solute carrier family 2, facilitated glucose transporter, member 9 (SLC2A9), also known as glucose transporter type 9, Glut9. METHODS: A total of 145 participants were recruited in the period April-October 2008 from the Department of Mineral Research of the Medical School Osijek, Osijek, Croatia; 58 (40%) had confirmed nephrolithiasis and 87 (60%) were asymptomatic. Four single nucleotide polymorphisms (SNP) from the SLC2A9 gene were genotyped in both groups (rs733175, rs6449213, rs1014290, and rs737267). RESULTS: There was a weak but significant association of all 4 SNPs and nephrolithiasis (P=0.029 for rs733175; P=0.006 for rs6449213; P=0.020 for rs1014290, and P=0.011 for rs737267). Logistic regression in an age- and sex-adjusted model suggested that genotype C/T for rs6449213 had odds ratio for nephrolithiasis of 2.89 (95% confidence interval 1.13-7.40). This SNP explained a total of 4.4% of nephrolithiasis variance. CONCLUSION: Development of nephrolithiasis may be associated with SLC2A9 gene. Further studies are needed to clarify the role of SLC2A9 gene as a link between uric acid and nephrolithiasis.

Evaluation of the reliability of DNA typing in the process of identification of war victims in Croatia.

Aiming to estimate the frequency of various types of errors that can occur in the large-scale process of identification, we identified and compared genotypes of 911 parent-child pairs in the database of 3498 relatives of people that disappeared during the 1991/1992 war in Croatia. Genotypes of 891 pairs (97.8%) were matching, while 20 pairs did not match in one or more loci. Reanalysis of these samples revealed that out of 1822 analyzed genotypes, one genotype was completely wrong, and two genotypes had one wrong allele because of human errors. Five genotypes had a single wrong allele due to either polymerase chain reaction or electrophoresis errors. In five genotypes mutations were the cause of mismatch. Genetic inconsistencies with parentage were found in four "fathers" (4.2%) and three "mothers" (0.36%). As the majority of observed single-locus errors were caused by nonhuman errors, all databases produced with similar technology would probably have comparable level of errors.

Non-invasive prenatal paternity testing from maternal blood.

Prenatal paternity analysis can be performed only after invasive sampling of chorionic villi or amnionic fluid. Aiming to enable noninvasive paternity testing, we attempted to amplify fetal alleles from maternal plasma. Cell-free DNA was isolated from plasma of 20 pregnant women and amplified with ampFLSTR Identifiler and ampFLSTR Yfiler kits. Unfortunately, autosomal fetal alleles were heavily suppressed by maternal DNA, and the only locus that was reliably amplified with AmpFLSTR Identifiler kit was amelogenin, which revealed only fetal gender. Much better success was obtained with AmpFLSTR Yfiler kit, which, in the case of male fetuses, successfully amplified between six and 16 fetal loci. All amplified fetal alleles matched the alleles of their putative fathers, confirming the tested paternity. To the best of our knowledge, this is a first report of noninvasive prenatal paternity testing.

Empirical support for the reliability of DNA interpretation in Croatia.

The result of empirical testing of forensic DNA match probabilities for Croatia is reported. It is concluded that if consideration is given to relatedness and subpopulation effects the model of Balding and Nichols appears to give very good predictions.

Analysis of multiple loci can increase reliability of detection of fetal Y-chromosome DNA in maternal plasma.

OBJECTIVE: Aiming to develop more reliable methods for determination of fetal gender from maternal plasma we compared three different systems of polymerase chain reaction (PCR) detection of Y-chromosome DNA. METHODS: Cell-free DNA was isolated from 96 samples of maternal plasma and (1) amplified using AmpFLSTR-Identifiler (15 autosomal STR loci and amelogenin) or AmpFLSTR-Yfiler (16 Y-chromosome STR loci) kits and subsequently analyzed on ABI-PRISM 310 Genetic Analyzer, or (2) analyzed using Quantifiler-Y DNA-Quantification kit. Gender of fetuses was confirmed by cytogenetic analysis or phenotypically at birth. RESULTS AND CONCLUSIONS: AmpFLSTR-Identifiler and Quantifiler-Y Human-Quantification kits were rather reliable in determining fetal gender (92.5 and 98.1%, respectively), but false negatives were still present in both systems. AmpFLSTR-Yfiler was found to be fully reliable as it amplified Y-chromosome in all cases of male fetuses, and was thus 100% correct in determining fetal gender. In addition, it enabled comparison of polymorphic Y-chromosome loci between father and a child, thus further supporting specificity of obtained results.

Population substructure can significantly affect reliability of a DNA-led process of identification of mass fatality victims.

Aiming to evaluate the effects of population substructure on the reliability of a DNA correspondence in the process of human identification, we used the model of "in silico" constructed populations with and without substructure. Effects of population substructure were evaluated at the level of locus heterozygosity, Hardy-Weinberg equilibrium and mini-haplotype distribution. Inbreeding in a subpopulation of 100 individuals through 10 generations did not significantly alter the level of heterozygosity and Hardy-Weinberg equilibrium. However, analysis of mini-haplotype distribution revealed a significant homogenization in separated subpopulations. Average observed mini-haplotype frequency (f(o)) increased to threefold from expected values (f(e)), and the number of mini-haplotypes with f(o)/f(e) above 10 increased over sixfold, suggesting that the effects of population substructure on calculated likelihood ratios (LR) might be larger than previously estimated. In most criminal cases, this would not represent a problem, whereas for identifications in large-scale mass fatality events, population substructure might considerably increase the risk of false identification.

How high should paternity index be for reliable identification of war victims by DNA typing?

AIM: To analyze statistically and logically the significance of genetic matches between skeletal remains and relatives of missing persons in the process of identification of war victims by DNA typing. METHODS: DNA was isolated from bone and blood samples and short tandem repeat (STR) loci were typed by using AmpFLSTR Profiler, Profiler Plus, and Identifiler kits. Novel mini-haplotype analysis that compares matches in all three-locus combinations of alleles was developed and used in the analysis of inbreeding in the group of 295 unrelated individuals. RESULTS: While comparing 98 skeletal remains exhumed in the process of identification of war victims in Croatia with over 3,000 genotypes of relatives of missing persons, we revealed 20 cases of 14-locus matches and 4 cases of 15-locus matches between unrelated people. We hypothesized that this unexpectedly high number of false matches might be a consequence of local inbreeding and supported this hypothesis with very low correlation between the probability of a genotype and the number of matching genotypes in the database (R(2) = 0.36). Further support for the hypothesis was obtained by the analysis of mini-haplotypes, which revealed up to 90% overrepresentation of some mini-haplotypes. CONCLUSIONS: STR DNA typing is the "golden standard" of human identification, but evidential value of a genetic match can be easily misinterpreted. Therefore, careful use of statistical methods is essential for the proper evaluation of laboratory results. Whenever possible, multiple relatives should be analyzed and other evidence based on the information about time, place, and other conditions of disappearance, as well as anthropological and other "classical" forensic data should always be put together and compared before any final decision about the identity is made.