Maternal obesity, interpregnancy weight changes and congenital heart defects in the offspring: a nationwide cohort study.

OBJECTIVE: To evaluate the association between maternal BMI and congenital heart defects (CHDs) in the offspring when including live births, stillbirths, aborted and terminated pregnancies and to investigate if maternal interpregnancy weight changes between the first and second pregnancy influences the risk of foetal CHDs. METHODS: A nationwide cohort study of all singleton pregnancies in Denmark from 2008 to 2018. Data were retrieved from the Danish Foetal Medicine Database, which included both pre- and postnatal diagnoses of CHDs. Children or foetuses with chromosomal aberrations were excluded. Odds ratios were calculated with logistic regression models for CHDs overall, severe CHDs and five of the most prevalent subtypes of CHDs. RESULTS: Of the 547 105 pregnancies included in the cohort, 5 442 had CHDs (1.0%). Risk of CHDs became gradually higher with higher maternal BMI; for BMI 25-29.9 kg/m2, adjusted odds ratio (aOR) 1.17 (95% CI 1.10-1.26), for BMI 30-34.9 kg/m2, aOR 1.21 (95% CI 1.09-1.33), for BMI 35-39.9 kg/m2, aOR 1.29 (95% CI 1.11-1.50) and for BMI ≥ 40 kg/m2, aOR 1.85 (95% CI 1.54-2.21). Data was adjusted for maternal age, smoking status and year of estimated due date. The same pattern was seen for the subgroup of severe CHDs. Among the atrioventricular septal defects (n = 231), an association with maternal BMI ≥ 30 kg/m2 was seen, OR 1.67 (95% CI 1.13-2.44). 109 654 women were identified with their first and second pregnancies in the cohort. Interpregnancy BMI change was associated with the risk of CHDs in the second pregnancy (BMI 2 to < 4 kg/m2: aOR 1.29, 95% CI 1.09-1.53; BMI ≥ 4 kg/m2: aOR 1.36, 95% CI 1.08-1.68). CONCLUSION: The risk of foetal CHDs became gradually higher with higher maternal BMI and interpregnancy weight increases above 2 BMI units were also associated with a higher risk of CHDs.

Trends in congenital clubfoot prevalence and co-occurring anomalies during 1994-2021 in Denmark: a nationwide register-based study.

BACKGROUND: Congenital talipes equinovarus (clubfoot) is a common musculoskeletal anomaly, with a suspected multifactorial etiopathogenesis. Herein, we used publicly available data to ascertain liveborn infants with clubfoot delivered in Denmark during 1994-2021, and to classify co-occurring congenital anomalies, estimate annual prevalence, and compare clubfoot occurrence with maternal smoking rates, a commonly reported risk factor. Characterizing this nationwide, liveborn cohort provides a population-based resource for etiopathogenic investigations and life course surveillance. METHODS: This case-cohort study used data from the Danish National Patient Register and Danish Civil Registration System, accessed through the publicly available Danish Biobank Register, to identify 1,315,282 liveborn infants delivered during 1994-2021 in Denmark to Danish parents. Among these, 2,358 infants (65.1% male) were ascertained with clubfoot and classified as syndromic (co-occurring chromosomal, genetic, or teratogenic syndromes) and nonsyndromic (isolated or co-occurring multiple congenital anomalies [MCA]). Annual prevalence estimates and corresponding 95% confidence intervals (CIs) for children with nonsyndromic clubfoot were estimated using Poisson regression and compared with population-based, maternal annual smoking rates obtained from publicly available resources. RESULTS: Infants most often presented with nonsyndromic clubfoot (isolated = 88.6%; MCA = 11.4%); limb and heart anomalies were the most frequently identified MCAs. Prevalence (per 1,000 liveborn infants) was 1.52 (CI 1.45-1.58) for isolated and 0.19 (CI 0.17-0.22) for MCA clubfoot. Prevalence estimates for both isolated and MCA clubfoot remained relatively stable during the study period, despite marked decreases in population-based maternal smoking rates. CONCLUSIONS: From 1994 to 2021, prevalence of nonsyndromic clubfoot in Denmark was relatively stable. Reduction in population-level maternal smoking rates did not seem to impact prevalence estimates, providing some support for the suspected multifactorial etiopathogenesis of this anomaly. This nationwide, liveborn cohort, ascertained and clinically characterized using publicly available data from the Danish Biobank Register, provides a population-based clinical and biological resource for future etiopathogenic investigations and life course surveillance.

Obstetrical complications in dichorionic twin pregnancies in women with polycystic ovary syndrome.

INTRODUCTION: Both women with polycystic ovary syndrome (PCOS) and women with twin pregnancies have increased risk of adverse pregnancy outcome. The aim of this study was to investigate the impact of PCOS and maternal androgen levels on the outcome of dichorionic twin pregnancy. MATERIAL AND METHODS: A retrospective study of 360 women with dichorionic twin pregnancies: 72 women with PCOS from a fertility clinic (years 1997-2010) and 288 women without PCOS from a hospital cohort (years 2005-2007). The obstetrical outcome was extracted from Danish National registers and supplemented by patient file data. In all, 65% of the PCOS group had a registered prepregnancy androgen level and these were stratified into normoandrogenic and hyperandrogenic women. The groups were compared by multiple regression analysis adjusting for mode of conception and prepregnancy body mass index. RESULTS: We found no overall impact of PCOS on the pregnancy outcome; the risks of preeclampsia, gestational diabetes and preterm delivery were comparable within the groups. However, five deliveries in the PCOS group compared with two in the control group occurred before gestational week 28. No difference in the obstetrical outcome between hyperandrogenic and normoandrogenic women was found. The body mass index in the PCOS population was lower than in the non-PCOS, possibly reflecting a higher socioeconomic status and a healthier lifestyle, which may underestimate the impact of a PCOS diagnosis. CONCLUSION: Neither PCOS nor maternal androgen levels confer additional risks to the outcome of dichorionic twin pregnancies of normal weight women.

Combined gating and trafficking defect in Kv11.1 manifests as a malignant long QT syndrome phenotype in a large Danish p.F29L founder family.

BACKGROUND: Congenital long QT syndrome (LQTS) is a hereditary cardiac channelopathy characterized by delayed ventricular repolarization, syncope, torsades de pointes and sudden cardiac death. Thirty-three members of five apparently 'unrelated' Danish families carry the KCNH2:c.87C> A; p.F29L founder mutation. METHODS AND RESULTS: Linkage disequilibrium mapping with microsatellites around KCNH2 enabled us to estimate the age of the founder mutation to be approximately 22 generations, corresponding to around 550 years. Neighbouring-Joining analysis disclosed one early and three later nodes. The median QTc time of the carriers was 490 ms (range: 415-589 ms) and no difference was seen between the different branches of the family. The mutation is malignant with a penetrance of 73%. Ten F29L carriers received implantable defibrillators (ICDs) (median age at implant 20 years), and of those four individuals experienced eight appropriate shocks. Patch-clamp analysis in HEK 293 cells, performed at 34°C disclosed a loss-of-function phenotype with fast deactivation, reduced steady-state inactivation current density and a positive voltage shift in inactivation. Western blotting of HEK 293 cells transfected with KCNH2:WT and KCNH2:c.87C> A revealed a reduced fraction of fully glycosylated hERG:p.F29L suggesting that this mutation results in defective trafficking. CONCLUSION: The altered channel gating kinetics in combination with defective trafficking of mutated channels is expected to result in reduced repolarizing current density and, thus, a LQTS phenotype.

Mutations in Danish patients with long QT syndrome and the identification of a large founder family with p.F29L in KCNH2.

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.

Ethical issues related to screening for preeclampsia.

The implementation of new methods of treating and preventing disease raises many question of both technical and moral character. Currently, many studies focus on developing a screening test for preeclampsia (PE), a disease complicating 2-8% of pregnancies, potentially causing severe consequences for pregnant women and their fetuses. The purpose is to develop a test that can identify pregnancies at high risk for developing PE sufficiently early in pregnancy to allow for prophylaxis. However, the question of implementing a screening test for PE does not only involve an evaluation of technical feasibility and clinical efficacy, it also requires an analysis of how the test influences the conditions and choices for those tested. This study evaluates state-of-the-art techniques for preeclampsia screening in an ethical framework, pointing out the central areas of moral relevance within the context of such screening activity. Furthermore, we propose ethical guidelines that a screening programme for PE should meet in order to become an uncontroversial addition to prenatal health care.

The role of CAV3 in long-QT syndrome: clinical and functional assessment of a caveolin-3/Kv11.1 double heterozygote versus caveolin-3 single heterozygote.

BACKGROUND: Mutations in CAV3, coding for caveolin-3, the major constituent scaffolding protein of cardiac caveolae, have been associated with skeletal muscle disease, cardiomyopathy, and most recently long-QT syndrome (LQTS) and sudden infant death syndrome. We examined the occurrence of CAV3 mutations in a large cohort of patients with LQTS. METHODS AND RESULTS: Probands with LQTS (n=167) were screened for mutations in CAV3 using direct DNA sequencing. A single proband (0.6%) was found to be a heterozygous carrier of a previously described missense mutation, caveolin-3:p.T78M. The proband was also a heterozygous carrier of the trafficking-deficient Kv11.1:p.I400N mutation. The caveolin-3:p.T78M mutation was found isolated in 3 family members, none of whom had a prolonged QTc interval. Coimmunoprecipitations of caveolin-3 and the voltage-gated potassium channel subunit (Kv11.1) were performed, and the electrophysiological classification of the Kv11.1 mutant was carried out by patch-clamp technique in human embryonic kidney 293 cells. Furthermore, the T-wave morphology was assessed in mutation carriers, double mutation carriers, and nonmutation carriers by applying a morphology combination score. The morphology combination score was normal for isolated caveolin-3:p.T78M carriers and of LQT2 type in double heterozygotes. CONCLUSIONS: Mutations in CAV3 are rare in LQTS. Furthermore, caveolin-3:p.T78M did not exhibit a LQTS phenotype. Because no association has ever been found between LQTS and isolated CAV3 mutations, we suggest that LQTS9 is considered a provisional entity.

[Short QT syndrome as an inherited condition]. / Kort QT-syndrom som arvelig sygdom.

Inherited ion-channel disorders can lead to life-threatening cardiac arrhythmias. A recent, rare entity has been discovered and termed short QT syndrome due to its electrocardiac features in conjunction with atrial and ventricular tachyarrhythmias as well as syncope and sudden cardiac death. The basis of the new syndrome is genetic and this review covers the genes responsible for the condition as well as the pathophysiology and diagnostic challenges involved in the syndrome. Furthermore, treatment for this new arrhythmic syndrome is reviewed.

Polymorphisms in the RNASE3 gene are associated with susceptibility to cerebral malaria in Ghanaian children.

BACKGROUND: Cerebral malaria (CM) is the most severe outcome of Plasmodium falciparum infection and a major cause of death in children from 2 to 4 years of age. A hospital based study in Ghana showed that P. falciparum induces eosinophilia and found a significantly higher serum level of eosinophil cationic protein (ECP) in CM patients than in uncomplicated malaria (UM) and severe malaria anemia (SA) patients. Single nucleotide polymorphisms (SNPs) have been described in the ECP encoding-gene (RNASE3) of which the c.371G>C polymorphism (rs2073342) results in an arginine to threonine amino acid substitution p.R124T in the polypeptide and abolishes the cytotoxicity of ECP. The present study aimed to investigate the potential association between polymorphisms in RNASE3 and CM. METHODOLOGY/PRINCIPAL FINDINGS: The RNASE3 gene and flanking regions were sequenced in 206 Ghanaian children enrolled in a hospital based malaria study. An association study was carried out to assess the significance of five SNPs in CM (n=45) and SA (n=56) cases, respectively. The two severe case groups (CM and SA) were compared with the non-severe control group comprising children suffering from UM (n=105). The 371G allele was significantly associated with CM (p=0.00945, OR=2.29, 95% CI=1.22-4.32) but not with SA. Linkage disequilibrium analysis demonstrated significant linkage between three SNPs and the haplotype combination 371G/*16G/*94A was strongly associated with susceptibility to CM (p=0.000913, OR=4.14, 95% CI=1.79-9.56), thus, defining a risk haplotype. The RNASE3 371GG genotype was found to be under frequency-dependent selection. CONCLUSIONS/SIGNIFICANCE: The 371G allele of RNASE3 is associated with susceptibility to CM and forms part of a risk associated haplotype GGA defined by the markers: rs2073342 (G-allele), rs2233860 (G-allele) and rs8019343 (A-allele) respectively. Collectively, these results suggest a hitherto unrecognized role for eosinophils in CM pathogenesis.

ADAM 12 may be used to reduce the false positive rate of first trimester combined screening for Down syndrome.

BACKGROUND: ADAM12 has been shown to be an efficient maternal serum marker for Down syndrome (DS) in the first trimester; but recent studies, using a second generation assay, have not confirmed these findings. We examined the efficiency of a second generation assay for ADAM12. MATERIALS AND METHODS: ADAM12 concentrations were determined in 28 first trimester DS and 503 control pregnancies using a novel Research Delfia ADAM12 kit. Log10MoM distributions of ADAM12 and correlations with other markers were established. Population performance of screening was estimated by Monte Carlo simulation. RESULTS: ADAM12 was significantly reduced in the first trimester in DS pregnancies with a log10MoM of -0.1621 (equivalent to 0.68 MoM) (p < 0.001). The reduction decreased with advancing gestational age. ADAM12 used with PAPP-A + hCG beta + NT (CUB screening) increased the detection rate (DR) from 86% to 89% for a false positive rate (FPR) of 5%. When used for a fixed DR of 90%, the addition of ADAM12 resulted in a 25% reduction of the FPR. CONCLUSION: ADAM12 is a moderately effective DS marker. It is not a cost-effective addition to CUB screening, but may be used to reduce the FPR in selected high-risk cases.

Free leptin index and PAPP-A: a first trimester maternal serum screening test for pre-eclampsia.

BACKGROUND: Prophylaxis with low-dose aspirin may reduce the risk of pre-eclampsia (PE) if introduced in first trimester. The performance of first trimester maternal serum screening for PE using free leptin index (fLI) and PAPP-A, where fLI = leptin/leptin soluble receptor was studied. METHODS: First trimester serum samples from 126 PE pregnancies and 289 control pregnancies were studied. fLI and PAPP-A were converted into gestational age and maternal weight independent log MoM values of PAPP-A and fLI. The screening performance of markers was studied by receiver-operator-characteristics curves. The performance of population screening was estimated by Monte Carlo simulation. RESULTS: fLI was significantly (p < 0.001) elevated [mean log MoM 0.2165 (SD: 0.2604)] compared to controls [mean log MoM -0.0368 (SD: 0.3132)] and PAPP-A was significantly (p < 0.001) reduced [mean log MoM -0.0133 (SD: 0.2661)] compared to controls [mean log MoM 0.0474 (SD: 0.2521)] in PE pregnancies. There was no correlation between fLI and PAPP-A in control or PE pregnancies. Combined fLI and PAPP-A screening for PE had estimated population detection rates of 22% and 35% for false positives rates of 6% and 12%, respectively. CONCLUSION: Combining PAPP-A and fLI improves screening performance for PE compared to single marker screening.