Variability of human Alpha-1-acid glycoprotein N-glycome in a Caucasian population.

AIM: Alpha-1-acid glycoprotein (AGP) is a highly glycosylated protein in human plasma and one of the most abundant acute phase proteins in humans. Glycosylation plays a crucial role in its biological functions, and alterations in AGP N-glycome have been associated with various diseases and inflammatory conditions. However, large-scale studies of AGP N-glycosylation in the general population are lacking. METHODS: Using recently developed high-throughput glycoproteomic workflow for site-specific AGP N-glycosylation analysis, 803 individuals from the Croatian island of Korcula were analyzed and their AGP N-glycome data associated with biochemical and physiological traits, as well as different environmental factors. RESULTS: After regression analysis, we found that AGP N-glycosylation is strongly associated with sex, somewhat less with age, along with multiple biochemical and physiological traits (e.g. BMI, triglycerides, uric acid, glucose, smoking status, fibrinogen). CONCLUSION: For the first time we have extensively explored the inter-individual variability of AGP N-glycome in a general human population, demonstrating its changes with sex, age, biochemical, and physiological status of individuals, providing the baseline for future population and clinical studies.

Meta-GWAS Reveals Novel Genetic Variants Associated with Urinary Excretion of Uromodulin.

BACKGROUND: Uromodulin, the most abundant protein excreted in normal urine, plays major roles in kidney physiology and disease. The mechanisms regulating the urinary excretion of uromodulin remain essentially unknown. METHODS: We conducted a meta-analysis of genome-wide association studies for raw (uUMOD) and indexed to creatinine (uUCR) urinary levels of uromodulin in 29,315 individuals of European ancestry from 13 cohorts. We tested the distribution of candidate genes in kidney segments and investigated the effects of keratin-40 (KRT40) on uromodulin processing. RESULTS: Two genome-wide significant signals were identified for uUMOD: a novel locus (P 1.24E-08) over the KRT40 gene coding for KRT40, a type 1 keratin expressed in the kidney, and the UMOD-PDILT locus (P 2.17E-88), with two independent sets of single nucleotide polymorphisms spread over UMOD and PDILT. Two genome-wide significant signals for uUCR were identified at the UMOD-PDILT locus and at the novel WDR72 locus previously associated with kidney function. The effect sizes for rs8067385, the index single nucleotide polymorphism in the KRT40 locus, were similar for both uUMOD and uUCR. KRT40 colocalized with uromodulin and modulating its expression in thick ascending limb (TAL) cells affected uromodulin processing and excretion. CONCLUSIONS: Common variants in KRT40, WDR72, UMOD, and PDILT associate with the levels of uromodulin in urine. The expression of KRT40 affects uromodulin processing in TAL cells. These results, although limited by lack of replication, provide insights into the biology of uromodulin, the role of keratins in the kidney, and the influence of the UMOD-PDILT locus on kidney function.

Genome-Wide Meta-Analysis Identifies Multiple Novel Rare Variants to Predict Common Human Infectious Diseases Risk.

Infectious diseases still threaten global human health, and host genetic factors have been indicated as determining risk factors for observed variations in disease susceptibility, severity, and outcome. We performed a genome-wide meta-analysis on 4624 subjects from the 10,001 Dalmatians cohort, with 14 infection-related traits. Despite a rather small number of cases in some instances, we detected 29 infection-related genetic associations, mostly belonging to rare variants. Notably, the list included the genes CD28, INPP5D, ITPKB, MACROD2, and RSF1, all of which have known roles in the immune response. Expanding our knowledge on rare variants could contribute to the development of genetic panels that could assist in predicting an individual's life-long susceptibility to major infectious diseases. In addition, longitudinal biobanks are an interesting source of information for identifying the host genetic variants involved in infectious disease susceptibility and severity. Since infectious diseases continue to act as a selective pressure on our genomes, there is a constant need for a large consortium of biobanks with access to genetic and environmental data to further elucidate the complex mechanisms behind host-pathogen interactions and infectious disease susceptibility.

Genome-Wide Association Transethnic Meta-Analyses Identifies Novel Associations Regulating Coagulation Factor VIII and von Willebrand Factor Plasma Levels.

BACKGROUND: Factor VIII (FVIII) and its carrier protein von Willebrand factor (VWF) are associated with risk of arterial and venous thrombosis and with hemorrhagic disorders. We aimed to identify and functionally test novel genetic associations regulating plasma FVIII and VWF. METHODS: We meta-analyzed genome-wide association results from 46 354 individuals of European, African, East Asian, and Hispanic ancestry. All studies performed linear regression analysis using an additive genetic model and associated ≈35 million imputed variants with natural log-transformed phenotype levels. In vitro gene silencing in cultured endothelial cells was performed for candidate genes to provide additional evidence on association and function. Two-sample Mendelian randomization analyses were applied to test the causal role of FVIII and VWF plasma levels on the risk of arterial and venous thrombotic events. RESULTS: We identified 13 novel genome-wide significant ( P≤2.5×10-8) associations, 7 with FVIII levels ( FCHO2/TMEM171/TNPO1, HLA, SOX17/RP1, LINC00583/NFIB, RAB5C-KAT2A, RPL3/TAB1/SYNGR1, and ARSA) and 11 with VWF levels ( PDHB/PXK/KCTD6, SLC39A8, FCHO2/TMEM171/TNPO1, HLA, GIMAP7/GIMAP4, OR13C5/NIPSNAP, DAB2IP, C2CD4B, RAB5C-KAT2A, TAB1/SYNGR1, and ARSA), beyond 10 previously reported associations with these phenotypes. Functional validation provided further evidence of association for all loci on VWF except ARSA and DAB2IP. Mendelian randomization suggested causal effects of plasma FVIII activity levels on venous thrombosis and coronary artery disease risk and plasma VWF levels on ischemic stroke risk. CONCLUSIONS: The meta-analysis identified 13 novel genetic loci regulating FVIII and VWF plasma levels, 10 of which we validated functionally. We provide some evidence for a causal role of these proteins in thrombotic events.

Genome-wide meta-analysis identifies novel gender specific loci associated with thyroid antibodies level in Croatians.

Autoimmune thyroid diseases (AITD) are multifactorial endocrine diseases most frequently accompanied by Tg and TPO autoantibodies. Both antibodies have a higher prevalence in females and act under a strong genetic influence. To identify novel variants underlying thyroid antibody levels, we performed GWAS meta-analysis on the plasma levels of TgAb and TPOAb in three Croatian cohorts, as well as gender specific GWAS and a bivariate analysis. No significant association was detected with the level of TgAb and TPOAb in the meta-analysis of GWAS or bivariate results for all individuals. The bivariate analysis in females only revealed a genome-wide significant association for the locus near GRIN3A (rs4457391, P = 7.76 × 10-9). The same locus had borderline association with TPOAb levels in females (rs1935377, P = 8.58 × 10-8). In conclusion, we identified a novel gender specific locus associated with TgAb and TPOAb levels. Our findings provide a novel insight into genetic and gender differences associated with thyroid antibodies.

Coronavirus epidemic in Croatia: case fatality decline during summer?

AIM: To describe the SARS-CoV-2 epidemic pattern in Croatia during February-September 2020 and compare the case fatality ratio (CFR) between spring and summer. METHODS: National data were used to calculate the weekly and monthly CFRs, stratified by three age groups: 0-64, 65-79, and 80+ years. We also calculated the standardized mortality ratios (SMR) to offset the differences in age composition. RESULTS: The epidemic consisted of the initial wave, a trough in June, and two conjoined summer waves, yielding 17206 coronavirus disease 2019 cases and 290 deaths. While the number of confirmed cases nearly quadrupled during summer, case fatality estimates decreased; CFR in spring was 4.81 (95% confidence interval 3.91-5.71), compared with 1.24 (1.06-1.42) in summer. The SMR for summer was 0.45 (0.37-0.55), suggesting that the case fatality risk halved compared with spring. Cardiovascular comorbidity was an important risk factor for case fatality (SMR 2.63 [2.20-3.13] during spring and 1.28 [1.02-1.59] during summer). The risk of death in ventilated patients remained unchanged (SMR 0.98 [0.77-1.24]). CONCLUSIONS: The epidemic dynamics suggests summer decline in case fatality, except in ventilated patients. While the effect of comorbidity also decreased, cardiovascular comorbidity remained an important risk factor for death even during summer. A plethora of possible confounders and an ever-changing landscape of SARS-CoV-2 epidemic in Croatia require constant monitoring and evaluation, with an aim to prevent the uncontrolled spread of the virus and a disruption of health care functioning.

Adherence to epidemiological measures and related knowledge and attitudes during the coronavirus disease 2019 epidemic in Croatia: a cross-sectional study.

AIM: To assess the use of personal protective equipment (PPE) and related knowledge and attitudes during the coronavirus disease 2019 epidemic in Croatia. METHODS: The online survey, conducted on social media in May 2020, yielded 1393 responses across the country (66% from the Adriatic area). The questionnaire consisted of socio-demographic questions and questions on the knowledge, attitudes, and behaviors related to PPE use. The χ2 test, t test, and multivariate logistic regression were used in data analysis. RESULTS: As many as 84.0% of participants reported the compliance with social distancing measures, while 52.8% reported using PPE (mask and/or gloves) when shopping or visiting friends and family. Participants demonstrated good knowledge (mean of 10.4 [95% CI 10.3-10.4] correct answers out of 13 questions) and neutral to moderately positive attitude about PPE use (mean of 36.6 [36.1-37.1] out of 50 points). Participants with higher education, women, and health care workers had a greater probability for having a high knowledge score. Women, older individuals, public transport users, people with more positive PPE use attitude, and those who complied with social distancing had a higher probability of PPE use, while health care workers and highly educated participants had a reduced probability of PPE use in public. CONCLUSIONS: Croatians had good knowledge and neutral to moderately positive attitudes about PPE use. Nevertheless, health authorities need to promote positive attitudes about PPE use in order to retain trust and compliance with epidemiological measures.

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.

Searching for carbonylome biomarkers of aging - development and validation of the proteomic method for quantification of carbonylated protein in human plasma.

AIM: To develop a method for measuring protein carbonylation in human plasma and serum samples, which was previously implied in numerous age-related phenotypes. METHODS: Protein expression and carbonylation were analyzed in plasma samples obtained from 12 healthy human individuals by using a novel method that combines affinity-based albumin and immunoglobulin G removal, and aminooxy dyeing in one- or two-dimensional gels. In addition, carbonylome profile of plasma and serum was compared. Coefficients of variation and intra-class correlation coefficients were used in statistical analysis. RESULTS: Following a step-wise laboratory development and optimization process, we measured the protein expression and carbonylation for 813 proteins from the plasma. The analysis of repeated measurements suggested excellent coefficients of variation, which rarely exceeded 10%. The average value of intra-class correlation based on absolute agreement (ICC) for protein expression was 0.97±0.02, while for carbonylation it was 0.73±0.24. The removal of the most extreme protein outlier in carbonylation assessment increased the average ICC to 0.87±0.04. Low protein spot volume substantially reduced repeatability. Serum carbonylation estimates were similar to those from plasma, with the ICC in the range of 0.86-0.89. CONCLUSION: We developed a reliable method for the measurement of human plasma protein carbonylation, which can be used for the assessment of carbonylome biomarkers of aging.

The effect of multiple nutrients on plasma parathyroid hormone level in healthy individuals.

Although the effect of isolated nutrients on plasma parathyroid hormone (PTH) is somewhat familiar, the effect of multiple nutrients on plasma PTH level has not yet been studied. The aim of this study was to identify groups of food items that are associated with the plasma PTH level in healthy individuals. This cross-sectional study enrolled 1180 healthy individuals from Croatia with plasma PTH levels inside the referent values. A food frequency questionnaire containing 58 food items was completed to evaluate the dietary intake. We used principal component analysis to reduce food items into dietary groups, followed by linear regression analysis to test the association between dietary groups and the level of PTH. The results indicate that different sorts of vegetables (p = .006), sausages, salami, mushrooms, eggs (p = .033), as well as white bread (p = .009) are associated with the increase, while bran bread (p = .009) is associated with the decreased plasma PTH level.

A meta-analysis of 120 246 individuals identifies 18 new loci for fibrinogen concentration.

Genome-wide association studies have previously identified 23 genetic loci associated with circulating fibrinogen concentration. These studies used HapMap imputation and did not examine the X-chromosome. 1000 Genomes imputation provides better coverage of uncommon variants, and includes indels. We conducted a genome-wide association analysis of 34 studies imputed to the 1000 Genomes Project reference panel and including ∼120 000 participants of European ancestry (95 806 participants with data on the X-chromosome). Approximately 10.7 million single-nucleotide polymorphisms and 1.2 million indels were examined. We identified 41 genome-wide significant fibrinogen loci; of which, 18 were newly identified. There were no genome-wide significant signals on the X-chromosome. The lead variants of five significant loci were indels. We further identified six additional independent signals, including three rare variants, at two previously characterized loci: FGB and IRF1. Together the 41 loci explain 3% of the variance in plasma fibrinogen concentration.

Genome-wide meta-analysis identifies novel loci associated with parathyroid hormone level.

BACKGROUND: Parathyroid hormone (PTH) is one of the principal regulators of calcium homeostasis. Although serum PTH level is mostly accounted by genetic factors, genetic background underlying PTH level is insufficiently known. Therefore, the aim of this study was to identify novel genetic variants associated with PTH levels. METHODS: We performed GWAS meta-analysis within two genetically isolated Croatian populations followed by replication analysis in a Croatian mainland population and we also combined results across all three analyzed populations. The analyses included 2596 individuals. A total of 7,411,206 variants, imputed using the 1000 Genomes reference panel, were analysed for the association. In addition, a sex-specific GWAS meta-analyses were performed. RESULTS: Polymorphisms with the lowest P-values were located on chromosome 4 approximately 84 kb of the 5' of RASGEF1B gene. The most significant SNP was rs11099476 (P = 1.15 × 10-8). Sex-specific analysis identified genome-wide significant association of the variant rs77178854, located within DPP10 gene in females only (P = 2.21 × 10- 9). There were no genome-wide significant findings in the meta-analysis of males. CONCLUSIONS: We identified two biologically plausible novel loci associated with PTH levels, providing us with further insights into the genetics of this complex trait.

Mortality patterns in Southern Adriatic islands of Croatia: a registry-based study.

AIM: To investigate the mortality patterns on the Southern Adriatic islands of Croatia and compare them with those in two, mainly coastal, mainland counties. METHODS: In this registry-based study we used the official mortality register data to analyze the mortality patterns on seven Croatian islands (Brac, Hvar, Korcula, Lastovo, Mljet, Solta, and Vis) and Peljesac peninsula in the 1998-2013 period and calculated the average lifespan, life expectancy, and standardized mortality ratios (SMR). We compared the leading causes of death with those in the mainland population of two southernmost Croatian counties. RESULTS: The average lifespan of the island population was 3-10 years longer for men and 2-7 years longer for women than that on the mainland. All-cause SMRs were significantly lower for both men and women on Korcula, Brac, Mljet, and Peljesac but significantly higher for women on Solta (1.22; 95% confidence intervals 1.07-1.38). The leading causes of death on the islands were cardiovascular diseases, with higher percentages in men and lower in women in comparison with those on the mainland. There were no substantial differences in the life expectancy at birth. CONCLUSIONS: Despite longer lifespan, lack of differences in life expectancy at birth suggests that the recent generations of islanders no longer show beneficial mortality patterns, possibly due to diminishing adherence to the Mediterranean diet and lifestyle. Restoring the traditional lifestyles is a public health priority, with the ultimate aim of reducing inequalities and improving the health of island inhabitants.

Association of Established Thyroid-stimulating Hormone and Free Thyroxine Genetic Variants with Hashimoto's Thyroiditis.

Hashimoto's thyroiditis (HT), the most frequent autoimmune thyroid disease (AITD), is characterized by chronic inflammation of the thyroid gland that usually results in hypothyroidism. Thyroid-stimulating hormone (TSH) and free thyroxine (FT4) levels are used as clinical determinants of thyroid function. The main aim of this study was to explore the association of established TSH and FT4 genetic variants with HT. We performed a case-control analysis using 23 genetic markers in 200 HT patients and 304 controls. Additionally, we tested the association of selected variants with several thyroid-related quantitative traits in HT cases only. Two genetic variants showed nominal association with HT: rs11935941 near NR3C2 gene (p = 0.0034, OR = 0.57, 95% CI = 0.39-0.83) and rs1537424 near MBIP gene (p = 0.0169, OR = 0.72, 95% CI = 0.55-0.94). Additionally, three SNPs showed nominal association with thyroglobulin antibody (TgAb) levels: rs4804416 in INSR gene (p = 0.0073, ß = -0.51), rs6435953 near IGFBP5 gene (p = 0.0081, ß = 0.75), and rs1537424 near MBIP gene (p = 0.0117, ß = 0.49). GLIS3 genetic variant rs10974423 showed nominal association with thyroid peroxidase antibody (TPOAb) levels (p = 0.0465, ß = -0.56) and NRG1 genetic variant rs7825175 was nominally associated with thyroid gland volume (p = 0.0272, ß = -0.18). All detected loci were previously related to thyroid function or pathology. Findings from our study suggest biological relevance of NR3C2 and MBIP with HT, although these loci require additional confirmation in a larger replication study.

Meta-analysis of 49†549 individuals imputed with the 1000 Genomes Project reveals an exonic damaging variant in ANGPTL4 determining fasting TG levels.

BACKGROUND: So far, more than 170 loci have been associated with circulating lipid levels through genome-wide association studies (GWAS). These associations are largely driven by common variants, their function is often not known, and many are likely to be markers for the causal variants. In this study we aimed to identify more new rare and low-frequency functional variants associated with circulating lipid levels. METHODS: We used the 1000 Genomes Project as a reference panel for the imputations of GWAS data from ∼60 000 individuals in the discovery stage and ∼90 000 samples in the replication stage. RESULTS: Our study resulted in the identification of five new associations with circulating lipid levels at four loci. All four loci are within genes that can be linked biologically to lipid metabolism. One of the variants, rs116843064, is a damaging missense variant within the ANGPTL4 gene. CONCLUSIONS: This study illustrates that GWAS with high-scale imputation may still help us unravel the biological mechanism behind circulating lipid levels.

Emotional and behavioral outcomes and quality of life in school-age children born as late preterm: retrospective cohort study.

Aim To determine the effect of late preterm birth and treatment at the intensive care unit (ICU) on school-age children's emotional and behavioral problems and quality of life (QoL). METHODS: Emotional and behavioral problems and QoL were investigated in 6-12-year-olds who were born late preterm at the University Hospital Center Split in the period from January 2002 to March 2008. The study included 126 late preterm children treated in ICU (LP-ICU group), 127 late preterm children not treated in ICU (LP-non-ICU group), and 131 full-term children treated in ICU (FT-ICU group). Emotional and behavioral difficulties were assessed using the Child Behavior Checklist. QoL was evaluated with the Royal Alexandra Hospital for Children Measure of Function questionnaire. The data was collected via telephone interview with mothers during 2014. RESULTS: Late preterm children had a nearly 5-fold risk for internalizing problems in comparison with FT-ICU children (OR 4.76, 95% confidence interval [CI] 2.37-9.56 and OR 4.82, 95% CI 2.25-10.37 in LP-ICU and LP-non-ICU children, respectively). They also had a greater risk for externalizing problems (OR 3.08, 95% CI 1.44-6.61 and OR 2.68, 95% CI 1.14-6.28, respectively) and total problems (OR 6.29, 95% CI 2.86-13.83 and OR 7.38, 95% CI 3.08-17.69, respectively) and a considerably increased risk for lower QoL (OR 12.79, 95% CI 5.56-29.41 and OR 5.05, 95% CI 2.04-12.48, respectively). CONCLUSION: Children born late preterm had a greater risk for emotional and behavioral problems and lower QoL during childhood than their full-term born peers and they experienced serious health problems upon birth.

Late preterm birth is a strong predictor of maternal stress later in life: Retrospective cohort study in school-aged children.

AIM: The aim of this study was to compare the level of stress in mothers of school-aged children born late preterm and admitted to the intensive care unit (ICU) with the level of maternal stress if a child was born late preterm and not admitted to the ICU as well as if a full-term child was admitted to the ICU. METHODS: In this retrospective cohort study the data were gathered via telephone interview with mothers. The Parenting Stress Index/Short Form was used to determine the level of stress in mothers. Background demographic characteristics, medically relevant variables, and the level of stress were tested using the chi-square test and Kruskal-Wallis test. Logistic regression was used in order to identify predictors of significant level of stress. RESULTS: Mothers of late preterm born children who were admitted to the ICU, as well as mothers of late preterm children who were not admitted had higher level of stress compared to mothers of full-term children. Namely, mothers of late preterm born children admitted to the ICU had 18-fold increase in risk for significant level of total stress (OR = 18.09; 95% CI 8.55 to 38.26) while 24-fold greater risk was observed in mothers of late preterm children who were not admitted to the ICU (OR = 24.05; 95% CI 10.66 to 54.26) in comparison to mothers of full-term born children. CONCLUSION: Results indicate that preterm birth and its complications are associated with a higher level of stress in mothers, that persists to school age.

Loci associated with N-glycosylation of human immunoglobulin G show pleiotropy with autoimmune diseases and haematological cancers.

Glycosylation of immunoglobulin G (IgG) influences IgG effector function by modulating binding to Fc receptors. To identify genetic loci associated with IgG glycosylation, we quantitated N-linked IgG glycans using two approaches. After isolating IgG from human plasma, we performed 77 quantitative measurements of N-glycosylation using ultra-performance liquid chromatography (UPLC) in 2,247 individuals from four European discovery populations. In parallel, we measured IgG N-glycans using MALDI-TOF mass spectrometry (MS) in a replication cohort of 1,848 Europeans. Meta-analysis of genome-wide association study (GWAS) results identified 9 genome-wide significant loci (P<2.27 × 10(-9)) in the discovery analysis and two of the same loci (B4GALT1 and MGAT3) in the replication cohort. Four loci contained genes encoding glycosyltransferases (ST6GAL1, B4GALT1, FUT8, and MGAT3), while the remaining 5 contained genes that have not been previously implicated in protein glycosylation (IKZF1, IL6ST-ANKRD55, ABCF2-SMARCD3, SUV420H1, and SMARCB1-DERL3). However, most of them have been strongly associated with autoimmune and inflammatory conditions (e.g., systemic lupus erythematosus, rheumatoid arthritis, ulcerative colitis, Crohn's disease, diabetes type 1, multiple sclerosis, Graves' disease, celiac disease, nodular sclerosis) and/or haematological cancers (acute lymphoblastic leukaemia, Hodgkin lymphoma, and multiple myeloma). Follow-up functional experiments in haplodeficient Ikzf1 knock-out mice showed the same general pattern of changes in IgG glycosylation as identified in the meta-analysis. As IKZF1 was associated with multiple IgG N-glycan traits, we explored biomarker potential of affected N-glycans in 101 cases with SLE and 183 matched controls and demonstrated substantial discriminative power in a ROC-curve analysis (area under the curve = 0.842). Our study shows that it is possible to identify new loci that control glycosylation of a single plasma protein using GWAS. The results may also provide an explanation for the reported pleiotropy and antagonistic effects of loci involved in autoimmune diseases and haematological cancer.

Meta-analysis of genome-wide association studies identifies six new Loci for serum calcium concentrations.

Calcium is vital to the normal functioning of multiple organ systems and its serum concentration is tightly regulated. Apart from CASR, the genes associated with serum calcium are largely unknown. We conducted a genome-wide association meta-analysis of 39,400 individuals from 17 population-based cohorts and investigated the 14 most strongly associated loci in ≤ 21,679 additional individuals. Seven loci (six new regions) in association with serum calcium were identified and replicated. Rs1570669 near CYP24A1 (P = 9.1E-12), rs10491003 upstream of GATA3 (P = 4.8E-09) and rs7481584 in CARS (P = 1.2E-10) implicate regions involved in Mendelian calcemic disorders: Rs1550532 in DGKD (P = 8.2E-11), also associated with bone density, and rs7336933 near DGKH/KIAA0564 (P = 9.1E-10) are near genes that encode distinct isoforms of diacylglycerol kinase. Rs780094 is in GCKR. We characterized the expression of these genes in gut, kidney, and bone, and demonstrate modulation of gene expression in bone in response to dietary calcium in mice. Our results shed new light on the genetics of calcium homeostasis.

Host genetics and susceptibility to congenital and childhood cytomegalovirus infection: a systematic review.

AIM: To summarize available evidence on the role of host genetics in the susceptibility to congenital and childhood cytomegalovirus (CMV) infections by conducting a systematic review of published studies. METHODS: We searched online databases (PubMed, Web of Science, Scopus and HuGe Navigator) for relevant studies with well-defined inclusion and exclusion criteria and assessed the risk of bias using novel Confounding-Selection-Information bias score (CSI). RESULTS: 5105 studies were initially identified, but only 5 met all the inclusion criteria and were analyzed in detail. Polymorphisms of the toll-like receptors (TLRs) and mannose-binding lectin (MBL) genes were shown to have an impact on the CMV infection in infants. Polymorphisms of the TLR2 (rs3804100, rs1898830), TLR4 (rs4986791), and TLR9 (rs352140) were shown to have a role in congenital CMV infection. Low MBL levels were associated with CMV infection in Chinese individuals, a finding that was not replicated in Caucasians. The overall credibility of evidence was weak. CONCLUSIONS: Based on currently available very limited amount of evidence, it is uncertain whether congenital and childhood CMV infections are under host genetic control. Additional primary studies are needed with more specific research hypotheses that will enable gradual understanding of specific mechanisms of the CMV pathogenesis. More genetic studies in the future will facilitate better understanding of host susceptibility and likely enable novel preventative and curative measures.