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Background: Hypertensive disorders of pregnancy (HDP) remain a leading cause of maternal morbidity and mortality worldwide, with implications for maternal and neonatal well-being in the short term and for long-term maternal cardiovascular health. Although the mechanisms behind HDP remain incompletely understood, evidence suggests that preeclampsia in particular is a syndrome with more than one distinct subtype. Objectives: The PEACH (PreEclampsia, Angiogenesis, Cardiac dysfunction, Hypertension) Study was established to identify new HDP subtyping systems reflecting aetiology and prognosis and to find markers of later cardiovascular disease risk associated with preeclampsia. Population: The PEACH Study recruited pregnant women referred to two Copenhagen-area hospitals with suspected preeclampsia (mean gestational age at enrolment: 36.7 weeks) and a group of frequency-matched pregnant women planning delivery at the same hospitals and healthy when enrolled mid-pregnancy. Design: Prospective, longitudinal pregnancy cohort. Methods: Participants underwent repeated third-trimester blood sample collection, longitudinal cardiac function assessments using the USCOM-1A during the third trimester and at 1 year postpartum and collection of placental samples immediately after delivery. Medical information was abstracted from medical records and hospital databases. Preliminary results: During 2016–2018, we recruited 1149 pregnant women, of whom 1101 were followed to delivery. Among 691 women enrolled with suspected preeclampsia, 310 and 172 developed preeclampsia and gestational hypertension respectively. Among 410 women with healthy pregnancies when enrolled mid-pregnancy, 37 later developed hypertensive disorders of pregnancy. Of 1089 women still in the cohort 1 year postpartum, 578 (53.1%) participated in the follow-up assessment. Conclusions: The PEACH Study's rich data from women with and without HDP will enable us to identify new, clinically useful HDP subtypes to aid in decision-making regarding monitoring and treatment. Continued postpartum follow-up will help us develop algorithms to identify women at risk of persistent postpartum cardiac dysfunction and later cardiovascular disease after pregnancies complicated by HDP.

The newly found Omicron SARS-CoV-2 variant of concern has rapidly spread worldwide. Omicron carries numerous mutations in key regions and is associated with increased transmissibility and immune escape. The variant has recently been divided into four subvariants with substantial genomic differences, in particular between Omicron BA.1 and BA.2. With the surge of Omicron subvariants BA.1 and BA.2, a large number of reinfections from earlier cases has been observed, raising the question of whether BA.2 specifically can escape the natural immunity acquired shortly after a BA.1 infection.To investigate this, we selected a subset of samples from more than 1,8 million cases of infections in the period from November 22, 2021, until February 11, 2022. Here, individuals with two positive samples, more than 20 and less than 60 days apart, were selected. From a total of 187 reinfection cases, we identified 47 instances of BA.2 reinfections shortly after a BA.1 infection, mostly in young unvaccinated individuals with mild disease not resulting in hospitalization or death.In conclusion, we provide evidence that Omicron BA.2 reinfections do occur shortly after BA.1 infections but are rare.

Henry Christensen,1 Jens Steen Nielsen,2 Karina Meden Sørensen,3 Mads Melbye,3 Ivan Brandslund1,41Department of Clinical Biochemistry, Vejle Hospital, Vejle, Denmark; 2The Danish Centre for Strategic Research in Type 2 Diabetes (DD2), Department of Endocrinology M, Diabetes Research Centre, Odense University Hospital, Odense, Denmark; 3Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark; 4Institute of Regional Health Research, University of Southern Denmark, Odense, DenmarkAbstract: Long-term storage of biological samples from patients has become increasingly important in studies of disease control and treatment. The first nationwide Danish diabetes project, ie, The Danish Center for Strategic Research in Type II Diabetes (DD2), aims to improve treatment and the long-term outcome of patients with newly diagnosed type 2 diabetes (T2D). The DD2 project includes establishment of a biobank with samples from 50,000 patients with newly diagnosed T2D. This paper describes how blood and urine samples from 10,000 patients per year are collected, handled, and stored. The biobank includes whole blood, DNA, and plasma and urine samples, all frozen at −80°C. Sampling tubes have been standardized and are sent to hospital outpatient clinics and general practitioners where samples are taken, handled, aliquoted, and returned by mail overnight in standardized cryostorage tubes. When received at the biobank, samples are frozen without further treatment. From each patient, 24 cryostorage tubes are stored. Each tube is labeled with a barcode that links the data to other information available in a clinical databank registry. When patients are enrolled in DD2, a questionnaire is filled out and a quality monitoring system ensures that patients, samples, and questionnaires can be linked together at all times. The biobank is located at Vejle Hospital and the Danish National Biobank at Statens Serum Institut. As of the end of March 2012, samples from 1186 patients have been stored, and currently samples from 8–10 patients arrive per day. We have established the first national biobank in Denmark where blood, DNA, and plasma and urine samples from patients with newly diagnosed T2D are systematically collected and stored. This biobank enables sophisticated analysis of genetic variation and response to treatment, as well as disease marker studies that better classify disease status, progression, and complications.Keywords: DD2, biobank, type 2 diabetes, logistics, implementation, biorepository, data registration

The prevalence of the 22q11.2 duplication is unknown in children with cardiovascular malformations (CVMs). As most individuals with the duplication are detected in the search for other conditions, especially the 22q11.2 deletion, CVMs associated with the duplication are subject to referral bias. We circumvented this bias by investigating the prevalence of the 22q11.2 duplication in a population-based cohort of children with CVMs. The study population was defined as children born in 2000-2008, who were registered in the Danish National Patient Registry with a diagnosis of CVM from one of the two national university departments of pediatric cardiology. Sensitive multiplex ligation-dependent probe amplification was performed on dried blood spot samples from each individual's neonatal screening test. The study population consisted of 2,952 children with CVMs, 2,424 of whom were eligible for genetic testing; 13 individuals (0.5% [0.3-0.9%]) carried the duplication. Nine individuals (69%) had not previously been tested for a copy number variation on chromosome 22q11.2 in the clinical setting for children with CVMs. We conclude that 22q11.2 duplication is rare in children with CVMs, and is primarily found in malformations that are also associated with the 22q11.2 deletion. © 2012 Wiley Periodicals, Inc.

Objective: Classical Hodgkin’s lymphoma (HL) lesions comprise few tumour cells, surrounded by numerous inflammatory cells. Like in other malignancies, the microenvironment is presumed to be clinic ...

Peter Agergaard1, Anders Hebert2, Jesper Bjerre3, Karina Meden Sørensen4, Charlotte Olesen3, John Rosendal Østergaard31Department of Pediatrics, Viborg Hospital, Viborg, Denmark; 2Department of Pediatrics, Copenhagen University Hospital, Rigshospitalet, Denmark; 3Department of Pediatrics, Aarhus University Hospital, Skejby, Denmark; 4Department of Clinical Biochemistry and Immunology, Statens Serum Institut, Copenhagen, DenmarkIntroduction: The present study was conducted to establish the positive predictive value of congenital cardiac malformation diagnoses registered in the Danish National Patient Registry (NPR), thereby exploring whether the NPR can serve as a valid tool for epidemiologic studies of congenital cardiac malformations.Materials and methods: The study population comprised every individual born from 2000 to 2008 who was registered in the NPR with a congenital cardiac malformation diagnosis and treated at one of the two national departments of pediatric cardiology. Positive predictive values were established comparing NPR information with the clinical record of each individual.Results: A total of 2952 patients with a total of 3536 diagnoses were eligible for validation. Review of their clinical records unveiled no patient without cardiac malformation. In 98% (98%–99%) of the cases, the NPR diagnosis could be found as the discharge diagnosis in the patient's clinical record, and in 90% (89%–91%) of the cases the NPR diagnosis was considered a true reflection of the patient's actual malformation.Conclusions: Our study verifies that the present study population retrieved from the NPR is a valid tool for epidemiological research within the topic of congenital cardiac malformations, given that the research question is not dependent on a fully established sensitivity of the NPR. Precautions should be made regarding cardiac malformations characterized by low prevalence or poor predictive values, and the reported validity should not be extrapolated beyond the study period.Keywords: congenital cardiac malformation, registry, validation

The 22q11 deletion syndrome, which is caused by a 1.5- to 3.0-megabase hemizygous deletion in chromosome 22q11.2, has a prevalence of 1/2000 to 1/4000. However, the syndrome presents with highly variable phenotypes and thus may be underestimated among Danish newborns. To establish a true incidence of 22q11.2 deletions among certain manifestations, eg, congenital heart disease, on selected Danes, a multiplex ligation-dependant probe amplification (MLPA) analysis was designed. The analysis was planned to be performed on DNA extracted from dried blood spot samples (DBSS) obtained from Guthrie cards collected during neonatal screening programs. However, the DNA concentration necessary for a standard MLPA analysis (20 ng) could not be attained from DBSS, and a novel MLPA design was developed to permit for analysis on limited amounts of DNA (2 ng). A pilot study is reported here that validates the new MLPA design using nine patients diagnosed with the 22q11.2 deletion and 101 controls. All deletions were identified using DNA extracted from DBSS, and no copy number variations were detected in the controls, resulting in a specificity and sensitivity of 100%. It is thereby concluded that the novel MLPA probe design is successful and reliable using minimal amounts of DNA. This allows for use of DBSS samples in a retrospective study of 22q11.2 deletion among certain manifestations associated with DiGeorge Syndrome.

Tumor necrosis factor (TNF) and interleukin 10 (IL10) are promising candidate susceptibility genes for non-Hodgkin lymphoma (NHL). Chromosomal translocation breakpoint genes are of interest, given their documented involvement in lymphoma progression.We analyzed 11 polymorphisms in BCL2, CCND1, MYC, TNF, and IL10 in a large, population-based, Danish-Swedish case-control study including 2,449 NHL cases and 1,980 controls. Relative risk of NHL was computed as odds ratios (OR).There was no clear evidence of associations between variants in BCL2, CCND1, and MYC and risk of NHL overall or subtypes. TNF rs1800629 was associated with risk of NHL (OR 1.53, 95% confidence interval, CI, 1.06-2.19 for minor allele homozygosity), T-cell lymphoma (OR 2.54, CI 1.27-5.09) and mantle cell lymphoma (OR 2.84, CI 1.38-5.87). IL10 rs1800890 was associated with risk of diffuse large B-cell lymphoma (OR 1.41, CI 1.08-1.85 for minor allele homozygosity) and mantle cell lymphoma (OR 1.77, CI 1.04-3.00). We did not replicate a previously reported interaction with autoimmunity.We found no support for a role of the studied variants in BCL2, CCND1, or MYC in risk of NHL or subtypes, but we provide further evidence of putative susceptibility loci in TNF and IL10 for specific NHL subtypes.

The American Heart Association (AHA) recommends family screening for hypertrophic cardiomyopathy (HCM). We assessed the outcome of family screening combining clinical evaluation and screening for sarcomere gene mutations in a cohort of 90 Danish HCM patients and their close relatives, in all 451 persons. Index patients were screened for mutations in all coding regions of 10 sarcomere genes (MYH7, MYL3, MYBPC3, TNNI3, TNNT2, TPM1, ACTC, CSRP3, TCAP, and TNNC1) and five exons of TTN. Relatives were screened for presence of minor or major diagnostic criteria for HCM and tracking of DNA variants was performed. In total, 297 adult relatives (>18 years) (51.2%) fulfilled one or more criteria for HCM. A total of 38 HCM-causing mutations were detected in 32 index patients. Six patients carried two disease-associated mutations. Twenty-two mutations have only been identified in the present cohort. The genetic diagnostic yield was almost twice as high in familial HCM (53%) vs. HCM of sporadic or unclear inheritance (19%). The yield was highest in families with an additional history of HCM-related clinical events. In relatives, 29.9% of mutation carriers did not fulfil any clinical diagnostic criterion, and in 37.5% of relatives without a mutation, one or more criteria was fulfilled. A total of 60% of family members had no mutation and could be reassured and further follow-up ceased. Genetic diagnosis may be established in approximately 40% of families with the highest yield in familial HCM with clinical events. Mutation-screening was superior to clinical investigation in identification of individuals not at increased risk, where follow-up is redundant, but should be offered in all families with relatives at risk for developing HCM. Hum Mutat 0,1–8, 2008. © 2008 Wiley-Liss, Inc.

The multiplex ligation-dependent probe amplification (MLPA) technique is a sensitive technique for relative quantification of up to 50 different nucleic acid sequences in a single reaction, and the technique is routinely used for copy number analysis in various syndromes and diseases. The aim of the study was to exploit the potential of MLPA when the DNA material is limited. The DNA concentration required in standard MLPA analysis is not attainable from dried blood spot samples (DBSS) often used in neonatal screening programs. A novel design of MLPA probes has been developed to permit for MLPA analysis on small amounts of DNA. Six patients with congenital adrenal hyperplasia (CAH) were used in this study. DNA was extracted from both whole blood and DBSS and subjected to MLPA analysis using normal and modified probes. Results were analyzed using GeneMarker and manual Excel analysis. A total number of 792 ligation events were analyzed. In DNA extracted from dried blood spot samples, 99.1% of the results were accurate compared to 99.9% of the results obtained in DNA from whole blood samples. This study clearly demonstrates that MLPA reactions with modified probes are successful and reliable with DNA concentrations down to 0.3 ng/microL (1.6 ng total). This broadens the diagnostic perspectives of samples of DBSS allowing for copy number variation analysis in general and particularly testing for CAH.

As the number of single-nucleotide polymorphism (SNP) screening and other mutation scanning studies have increased explosively, following the development of high-throughput instrumentation, it becomes even more important to have sufficient template DNA. The source of DNA is often limited, especially in epidemiological studies, which require many samples as well as enough DNA to perform numerous SNP screenings or mutation scannings. Therefore, the aim is to solve the problem of stock DNA limitation. This need has been an important reason for the development of whole genome amplification (WGA) methods. Several systems are based on Phi29 polymerase multiple displacement amplification (MDA) or on DNA fragmentation (OmniPlex). Using TaqMan SNP genotyping assays, we have tested four WGA systems -- AmpliQ Genomic Amplifier Kit, GenomiPhi, Repli-g, and GenomePlex -- on DNA extracted from Guthrie cards to evaluate the amplification bias, concordance- and call rates, cost efficiency, and flexibility. All systems successfully amplified picograms of DNA from Guthrie cards to micrograms of product without loss of heterozygosity and with minimal allelic bias. A modified AmpliQ set up was chosen for further evaluation. In all, 2,000 SNP genotyping results from amplified and nonamplified samples were compared and the concordance rates between the samples were 99.7%. The call rate using the TaqMan system was 99.8%. DNA extracted from Guthrie cards and amplified with one of the four evaluated WGA systems is applicable in epidemiological genetic screenings. System choice should be based on requirements for system flexibility, product yield, and use in subsequent analysis.

Whole genome amplification is an invaluable technique when working with DNA extracted from blood spots, as the DNA obtained from this source often is too limited for extensive genetic analysis. Two techniques that amplify the entire genome are common. Here, both are described with focus on the benefits and drawbacks of each system. However, in order to obtain the best possible WGA result the quality of input DNA extracted from the blood spot is essential, but also time consumption, flexibility in format and elution volume and price of the technology are factors influencing system choice. Here, three DNA extraction techniques are described and the above aspects are compared between the systems.

Whole genome amplification is an invaluable technique when working with DNA extracted from blood spots, as the DNA obtained from this source often is too limited for extensive genetic analysis. Two techniques that amplify the entire genome are common. Here, both are described with focus on the benefits and drawbacks of each system. However, in order to obtain the best possible WGA result the quality of input DNA extracted from the blood spot is essential, but also time consumption, flexibility in format and elution volume and price of the technology are factors influencing system choice. Here, three DNA extraction techniques are described and the above aspects are compared between the systems.

BACKGROUND: Long QT syndrome (LQTS) is a cardiac ion channelopathy which presents clinically with palpitations, syncope or sudden death. More than 700 LQTS-causing mutations have been identified in 13 genes, all of which encode proteins involved in the execution of the cardiac action potential. The most frequently affected genes, covering > 90% of cases, are KCNQ1, KCNH2 and SCN5A.METHODS: We describe 64 different mutations in 70 unrelated Danish families using a routine five-gene screen, comprising KCNQ1, KCNH2 and SCN5A as well as KCNE1 and KCNE2.RESULTS: Twenty-two mutations were found in KCNQ1, 28 in KCNH2, 9 in SCN5A, 3 in KCNE1 and 2 in KCNE2. Twenty-six of these have only been described in the Danish population and 18 are novel. One double heterozygote (1.4% of families) was found. A founder mutation, p.F29L in KCNH2, was identified in 5 "unrelated" families. Disease association, in 31.2% of cases, was based on the type of mutation identified (nonsense, insertion/deletion, frameshift or splice-site). Functional data was available for 22.7% of the missense mutations. None of the mutations were found in 364 Danish alleles and only three, all functionally characterised, were recorded in the Exome Variation Server, albeit at a frequency of < 1:1000.CONCLUSION: The genetic etiology of LQTS in Denmark is similar to that found in other populations. A large founder family with p.F29L in KCNH2 was identified. In 48.4% of the mutations disease causation was based on mutation type or functional analysis.

The human endogenous retrovirus HERV-K18 is located within intron 1 of CD48 on chromosome 1q and is still active in the human genome. Genetic variation in HERV-K18 single-nucleotide polymorphisms (SNPs) has previously been associated with an increased risk of schizophrenia (SZ) and with type 2 diabetes (T2D) among individuals with SZ. Here, we present a replication study of association of two SNPs in HERV-K18 and 19 tagSNPs in CD48 with (a) SZ and (b) T2D in patients with SZ in two Danish samples (total number of cases=750 and controls=1214). No association was found with SZ or with T2D among individuals with SZ for any of the investigated SNPs. However, one HERV-K18 SNP showed a tendency toward an association with T2D in younger SZ patients, in agreement with previous findings, but due to a very low sample size, this result needs to be further investigated.

Deletion of chromosome 22q11.2 is considered one of the most frequent genetic causes of cardiovascular malformations. It is frequently associated with conotruncal malformations, but may also be present among patients with nonconotruncal malformations. The aim of the present study was to establish the prevalence of the 22q11.2 deletion in an unselected population-based cohort of children with various cardiovascular malformations. The study population was defined as children born in 2000-2008 who were registered in the Danish National Patient Registry with a diagnosis of cardiovascular malformation from one of the two national departments of pediatric cardiology. Sensitive multiplex ligation-dependent probe amplification was performed on dried blood spot samples from each individual's neonatal screening test. Of 2,952 children with cardiovascular malformations, 2,478 were eligible for genetic testing. A total of 46 individuals (1.9% [1.4-2.5%]) carried the deletion, with the highest prevalence among individuals registered with interrupted aortic arch (22% [11-40]). The most frequent diagnoses among individuals carrying the deletion were tetralogy of Fallot (n = 15) and ventricular septal defect (n = 15). One in four cases had not been diagnosed in the usual clinical setting. The prevalence of 22q11.2 deletions in an unselected population-based cohort of children with cardiac malformations was 1.9% [1.4-2.5%]. Genetic testing of every individual registered with a conotruncal malformation would have achieved a diagnostic sensitivity of 70% in the present cohort. Prospective studies outlining testing recommendations in children with ventricular septal defect are warranted. © 2011 Wiley Periodicals, Inc.

Objective: An interaction between predisposing genes and environmental stressors is thought to underlie the neurodevelopmental disorder schizophrenia. In a targeted gene screening, we previously found that the minor allele of the single nucleotide polymorphism (SNP) rs6336 in the neurotrophic tyrosine kinase receptor 1 (NTRK1/TRKA) gene is associated with schizophrenia as a risk factor. Methods: We genotyped the TRKA SNP in a total of eight independent Caucasian schizophrenia casecontrol groups. Result: Remarkably, although in five of the groups a higher frequency of the risk allele was indeed found in the patients compared with the controls, in the three other groups the SNP acted as a protective factor. Conclusion: An intriguing possibility is that this dual character of the TRKA SNP is caused by its interaction with endophenotypic and/or epistatic factors.

N-methyl-D-aspartate (NMDA) receptors are very important for proper brain development and several lines of evidence support that hypofunction of the NMDA receptors are involved in the pathophysiology of schizophrenia. Gene variation and gene-environmental interactions involving the genes encoding the NMDA receptors are therefore likely to influence the risk of schizophrenia. The aim of this study was to determine (1) whether SNP variation in the genes (GRIN1, GRIN2A, GRIN2B, GRIN2C, and GRIN2D) encoding the NMDA receptor were associated with schizophrenia; (2) whether GRIN gene variation in the offspring interacted with maternal herpes simplex virus-2 (HSV-2) seropositivity during pregnancy influencing the risk of schizophrenia later in life. Individuals from three independently collected Danish case control samples were genotyped for 81 tagSNPs (in total 984 individuals diagnosed with schizophrenia and 1,500 control persons) and antibodies against maternal HSV-2 infection were measured in one of the samples (365 cases and 365 controls). Nine SNPs out of 30 in GRIN2B were significantly associated with schizophrenia. One SNP remained significant after Bonferroni correction (rs1806194, P(nominal) = 0.0008). Significant interaction between maternal HSV-2 seropositivity and GRIN2B genetic variation in the offspring were observed for seven SNPs and two remained significant after Bonferroni correction (rs1805539, P(nominal) = 0.0001 and rs1806205, P(nominal) = 0.0008). The significant associations and interactions were located at the 3' region of GRIN2B suggesting that genetic variation in this part of the gene may be involved in the pathophysiology of schizophrenia. © 2011 Wiley-Liss, Inc.

Introduction No consensus exists regarding the ability to detect the 22q11 deletion syndrome based on clinical assessment. Traditionally, diagnosis depends on clinical referral. Thus, individuals with typical manifestations are easily identified, but when manifestations are atypical or subclinical, diagnosis may be delayed or even missed. The aim of the present literature review was to evaluate the validity of clinical assessment as a method of predicting 22q11.2 deletions in individuals with congenital cardiac malformations. Methods We identified 14 studies in which clinical assessment was blinded to the result from the genetic analysis. Results Among 1458 patients, 159 (11% [9–13%]) carried the 22q11.2 deletion. The clinicians correctly identified 110 (69% [62–76%]) of them, whereas 49 (31% [24–38%]) would have remained undiagnosed if genetic screening had not been performed. Sensitivity, specificity, predictive value of positive and negative tests ranged from 0–100%, 43–100%, 7–100%, and 79–100%, respectively. Conclusions Clinical assessment identifies less than 3/4 patients with a 22q11.2 deletion, whereas more than 1/4 remain undiagnosed if genetic tests are not performed on a routine basis. In this review, we found that clinical assessment is not suited for detecting individuals to be tested for 22q11.2 deletions.

To identify susceptibility loci for classical Hodgkin's lymphoma (cHL), we conducted a genome-wide association study of 589 individuals with cHL (cases) and 5,199 controls with validation in four independent samples totaling 2,057 cases and 3,416 controls. We identified three new susceptibility loci at 2p16.1 (rs1432295, REL, odds ratio (OR) = 1.22, combined P = 1.91 x 10(-8)), 8q24.21 (rs2019960, PVT1, OR = 1.33, combined P = 1.26 x 10(-13)) and 10p14 (rs501764, GATA3, OR = 1.25, combined P = 7.05 x 10(-8)). Furthermore, we confirmed the role of the major histocompatibility complex in disease etiology by revealing a strong human leukocyte antigen (HLA) association (rs6903608, OR = 1.70, combined P = 2.84 x 10(-50)). These data provide new insight into the pathogenesis of cHL.

Udgivelsesdato: 2010-Feb

Genome-wide association scans in type 2 diabetes (T2D) have identified a risk variant, rs13266634 (Arg325Trp), in SLC30A8 on chromosome 8. SLC30A8 encodes a beta-cell specific zinc-ion transporter and rs13266634 has been shown to affect insulin secretion. Recently, autoantibodies for Slc30A8 with high predictive value were demonstrated in individuals with type 1 diabetes (T1D), making this gene an interesting T1D candidate gene. We genotyped rs13266634 in 3008 cases and controls and 246 families from Denmark. Association to T1D could not be demonstrated.