Retinopathy and Nephropathy in Type 1 Diabetic Patients – Association with Polymorphysms of Vitamin D-Receptor, Tnf, Neuro-D and Il-1 Receptor 1 Genes

Retinopathy and nephropathy are common late type 1 diabetes mellitus (T1D) complications. In this study we investigated whether individual differences in 4 candidate genes significantly contribute to development and progression of late complications in T1D patients. We examined 121 patients for the presence of diabetic retinopathy and nephropathy. We genotyped variants in vitamin D receptor (VDR) and tumor necrosis factor (TNF) genes in 47 patients and in NeuroD1 and interleukin-1 receptor 1 (IL1R1) genes in 35 patients. Diabetic retinopathy had 66 (55%) patients after a median of 13.0 years after diagnosis. Diabetic nephropathy had 14 (11.66%) patients, all of whom had already developed retinopathy. A significant correlation between the degree of diabetic retinopathy and mean microalbuminuria (MA) value has been found (c2=54.18, p<0.001). After correcting for duration of disease, only the VDR gene BsmI genotypes showed significant association with cumulative prevalence of diabetic retinopathy, while no investigated genetic polymorphysms could reliably predict diabetic nephropathy

NeuroD1 Gene and Interleukin-18 Gene Polymorphisms in Type 1 Diabetes in Dalmatian Population of Southern Croatia

Aim: To evaluate the frequency of known polymorphisms in the exon 2 of the NeuroD1 gene and in the interleukin (IL)-18 promoter region in patients with type 1 diabetes mellitus (T1DM) and in healthy control subjects in Dalmatia, Southern Croatia. Methods: A total of 134 unrelated patients (73 men and 61 women) and 132 consecutive unrelated healthy controls (61 men and 71 women) from the Dalmatian region of southern Croatia were recruited for the study. NeuroD1 genotypes (GG, GA, AA) were identified by means of polymerase chain reaction followed by restriction fragment length polymorphism (PCR/RFLP). IL-18 polymorphism in the position –137 of the promoter region was detected by using PCR sequence-specific primers. Results: Genotype distributions of both genes did not show significant difference between patients and controls. Conclusion: Our results suggest that NeuroD1 exon 2 and IL-18 promoter gene polymorphisms are not associated with development of T1DM susceptibility in the population of South Croatia. In addition to previously published positive correlations of these polymorphisms with development of T1DM among different world populations, our findings indicate the existence of ethnic variations in the association of these genes with disease development

Thyroid hormone levels are associated with metabolic components:A cross-sectional study

Aim: To analyze the association of thyroid function and hormone levels with metabolic syndrome (MetS) and its components. Methods: This cross-sectional population-based study involved 2183 Croatian individuals with no history of thyroid disease, hypertension, diabetes, and hyperlipidemia. MetS was diagnosed according to the National Cholesterol Education Program’s Adult Treatment Panel III criteria. Results: We found no association between thyroid function groups and the prevalence of MetS and its components. Clinically hypothyroid participants showed significantly higher triceps skinfold measurements than subclinically hypothyroid and euthyroid participants. Furthermore, clinically hypothyroid participants had higher abdominal skinfold thickness than subclinically hypothyroid participants. Otherwise, suprailiac and abdominal skinfold measurements were higher in the subclinically and clinically hyperthyroid group of participants compared with euthyroid and subclinically hypothyroid participants. A strong positive association of thyroid-stimulating hormone (TSH) and strong negative association of free triiodothyronine (fT3) and free thyroxine (fT4) levels with HOMA-IR and cholesterol levels were found. Furthermore, the fT4 level also showed a strong negative association with HDL and triceps skinfold thickness. Conclusions: This study supports the standing that TSH, fT3, and fT4 levels are important variables to determine the association of thyroid function with MetS

Ethical aspects of human biobanks: a systematic review

Aim To systematically assess the existing literature on ethical aspects of human biobanks. Method We searched the Web of Science and PubMed databases to find studies addressing ethical problems in biobanks with no limits set (study design, study population, time period, or language of publication). All identified articles published until November 2010 were included. We analyzed the type of published articles, journals publishing them, involvement of countries/institutions, year of publication, and citations received, and qualitatively assessed every article in order to identify ethical issues addressed by the majority of published research on human biobanking. Results Hundred and fifty four studies satisfied our review criteria. The studies mainly came from highly developed countries and were all published in the last two decades, with over half of them published in 2009 or 2010. They most commonly discussed the informed consent, privacy and identifiability, return of results to participants, importance of public trust, involvement of children, commercialization, the role of ethics boards, international data exchange, ownership of samples, and benefit sharing. Conclusions The focus on ethical aspects is strongly present through the whole biobanking research field. Although there is a consensus on the old and most typical ethical issues, with further development of the field and increasingly complex structure of human biobanks, these issues will likely continue to arise and accumulate, hence requiring constant re-appraisal and continuing discussion

Genome-wide analyses for personality traits identify six genomic loci and show correlations with psychiatric disorders

Personality is influenced by genetic and environmental factors1 and associated with mental health. However, the underlying genetic determinants are largely unknown. We identified six genetic loci, including five novel loci2,3, significantly associated with personality traits in a meta-analysis of genome-wide association studies (N = 123,132–260,861). Of these genomewide significant loci, extraversion was associated with variants in WSCD2 and near PCDH15, and neuroticism with variants on chromosome 8p23.1 and in L3MBTL2. We performed a principal component analysis to extract major dimensions underlying genetic variations among five personality traits and six psychiatric disorders (N = 5,422–18,759). The first genetic dimension separated personality traits and psychiatric disorders, except that neuroticism and openness to experience were clustered with the disorders. High genetic correlations were found between extraversion and attention-deficit– hyperactivity disorder (ADHD) and between openness and schizophrenia and bipolar disorder. The second genetic dimension was closely aligned with extraversion–introversion and grouped neuroticism with internalizing psychopathology (e.g., depression or anxiety)

An evaluation of different meta-analysis approaches in the presence of allelic heterogeneity

Meta-analysis has proven a useful tool in genetic association studies. Allelic heterogeneity can arise from ethnic background differences across populations being meta-analyzed (for example, in search of common frequency variants through genome-wide association studies), and through the presence of multiple low frequency and rare associated variants in the same functional unit of interest (for example, within a gene or a regulatory region). The latter challenge will be increasingly relevant in whole-genome and whole-exome sequencing studies investigating association with complex traits. Here, we evaluate the performance of different approaches to meta-analysis in the presence of allelic heterogeneity. We simulate allelic heterogeneity scenarios in three populations and examine the performance of current approaches to the analysis of these data. We show that current approaches can detect only a small fraction of common frequency causal variants. We also find that for low-frequency variants with large effects (odds ratios 2–3), single-point tests have high power, but also high false-positive rates. P-value based meta-analysis of summary results from allele-matching locus-wide tests outperforms collapsing approaches. We conclude that current strategies for the combination of genetic association data in the presence of allelic heterogeneity are insufficiently powered