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- Cuneo, Bettina F., et al.
(author)
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Mothers with long QT syndrome are at increased risk for fetal death : findings from a multicenter international study
- 2020
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In: American Journal of Obstetrics and Gynecology. - : MOSBY-ELSEVIER. - 0002-9378 .- 1097-6868. ; 222:3, s. 1-11
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Journal article (peer-reviewed)abstract
- BACKGROUND: Most fetal deaths are unexplained. Long QT syndrome is a genetic disorder of cardiac ion channels. Affected individuals, including fetuses, are predisposed to sudden death. We sought to determine the risk of fetal death in familial long QT syndrome, in which the mother or father carries the long QT syndrome genotype. In addition, we assessed whether risk differed if the long QT syndrome genotype was inherited from the mother or father. OBJECTIVE: This was a retrospective review of pregnancies in families with the 3 most common heterozygous pathogenic long QT syndrome genotypes in KCNQ1 (LQT1), KCNH2 (LQT2), or SCN5A (LQT3), which occur in approximately 1 in 2000 individuals. The purpose of our study was to compare pregnancy and birth outcomes in familial long QT syndrome with the normal population and between maternal and paternal carriers of the long QT syndrome genotype. We hypothesized that fetal death before (miscarriage) and after (stillbirths) 20 weeks gestation would be increased in familial long QT syndrome compared with the normal population and that the parent of origin would not affect birth outcomes. STUDY DESIGN: Our study was a multicenter observational case series of 148 pregnancies from 103 families (80 mothers, 23 fathers) with familial long QT syndrome (60 with LQT1, 29 with LQT2, 14 with LQT3) who were recruited from 11 international centers with expertise in hereditary heart rhythm diseases, pediatric and/or adult electrophysiology, and high-risk pregnancies. Clinical data-bases from these sites were reviewed for long QT syndrome that occurred in men or women of childbearing age (18-40 years). Pregnancy outcomes (livebirth, stillbirth, and miscarriage), birthweights, and gestational age at delivery were compared among long QT syndrome genotypes and between maternal vs paternal long QT syndrome-affected status with the use of logistic regression analysis. RESULTS: Most offspring (80%; 118/148) were liveborn at term; 66% of offspring (73/110) had long QT syndrome. Newborn infants of mothers with long QT syndrome were delivered earlier and, when the data were controlled for gestational age, weighed less than newborn infants of long QT syndrome fathers. Fetal arrhythmias were observed rarely, but stillbirths (fetal death at >20 weeks gestation) were 8 times more frequent in long QT syndrome (4% vs approximately 0.5%); miscarriages (fetal death at <= 20 weeks gestation) were 2 times that of the general population (16% vs 8%). The likelihood of fetal death was significantly greater with maternal vs paternal long QT syndrome (24.4% vs 3.4%; P = .036). Only 10% of all fetal deaths underwent postmortem long QT syndrome testing; 2 of 3 cases were positive for the family long QT syndrome genotype. CONCLUSION: This is the first report to demonstrate that mothers with long QT syndrome are at increased risk of fetal death and to uncover a previously unreported cause of stillbirth. Our results suggest that maternal effects of long QT syndrome channelopathy may cause placental or myometrial dysfunction that confers increased susceptibility to fetal death and growth restriction in newborn survivors, regardless of long QT syndrome status.
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2. |
- Cuneo, Bettina, et al.
(author)
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Fetal heart rate and arrhythmia profile predicts long QT syndrome (LQTS) genotype : Results of an 8-center international study
- 2018
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In: American Journal of Obstetrics and Gynecology. - : MOSBY-ELSEVIER. - 0002-9378 .- 1097-6868. ; 218:1, s. S93-S93
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Journal article (other academic/artistic)abstract
- Objective: 1. Determine if fetal heart rate (FHR) predicts LQTS across gestational ages (GA). 2. Ascertain genotype specific effects on FHR and rhythm.Study Design: FHR and rhythm data were ascertained from fetuses with maternal or paternal LQTS1, LQTS2 or LQTS3 genotype at 8 international centers. We reviewed obstetrical history including maternal beta blocker (BB) use. At each obstetrical visit, FHRs were calculated from an average of 3 heart beats (ultrasound) or 3 10-second periods of FHR auscultation (Doppler monitor) measured during fetal quiescence. Postnatal genetic testing was performed by commercial laboratories. We compared FHR in the 1st, 2nd and 3rd trimesters between fetuses with (LQTS+) and without (LQTS-) the family mutation by t-test. Differences in FHR between LQTS genotypes were compared by ANOVA. Log FHR was analyzed by a linear mixed effect model with GA as the continuous variable and adjusting for maternal BB use. The predictive ability of FHR to discriminate LQTS+ from LQTS- was addressed by ROC analysis, evaluating the magnitude of FHR (intercept) and change in FHR (slope) across GA.Results: Data were available on 51 LQTS+ and 27 LQTS-. Mean FHR differed between LQTS+ and LQTS- fetuses in 2nd and 3rd but not in the 1st trimesters (Table). The magnitude of FHR change in 2nd and 3rd trimesters discriminated LQTS + from LQTS- (both, p<0.05); with AUC of 0.81. FHR effect was most pronounced for LQTS1 and differed significantly between genotypes. LQTS3 did not exhibit a FHR effect at any GA. Only LQTS2 had signature LQTS arrhythmias (2◦ AV block and/or torsade de pointes). Maternal BB had no significant effect on FHR.Conclusion: In this study with a preponderance of LQTS1, FHR discriminated LQTS+ from LQTS- fetuses in the 2nd and 3rd trimesters. LQTS genotype appears to affect the fetal presentation of LQTS. These findings provide insight into the natural history of LQTS before birth and may facilitate early detection of LQTS1 and LQTS2 fetuses.
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- Jansweijer, Joeri A., et al.
(author)
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Heritability in genetic heart disease : the role of genetic background
- 2019
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In: Open heart. - : BMJ Publishing Group Ltd. - 2053-3624. ; 6:1
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Journal article (peer-reviewed)abstract
- Background: Mutations in genes encoding ion channels or sarcomeric proteins are an important cause of hereditary cardiac disease. However, the severity of the resultant disease varies considerably even among those with an identical mutation. Such clinical variation is often thought to be explained largely by differences in genetic background or ‘modifier genes’. We aimed to test the prediction that identical genetic backgrounds result in largely similar clinical expression of a cardiac disease causing mutation, by studying the clinical expression of mutations causing cardiac disease in monozygotic twins.Methods: We compared first available clinical information on 46 monozygotic twin pairs and 59 control pairs that had either a hereditary cardiomyopathy or channelopathy.Results: Despite limited power of this study, we found significant heritability for corrected QT interval (QTc) in long QT syndrome (LQTS). We could not detect significant heritability for structural traits, but found a significant environmental effect on thickness of the interventricular septum in hypertrophic cardiomyopathy.Conclusions: Our study confirms previously found robust heritability for electrical traits like QTc in LQTS, and adds information on low or lacking heritability for structural traits in heritable cardiomyopathies. This may steer the search for genetic modifiers in heritable cardiac disease.
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- Sandholm, Niina, et al.
(author)
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New susceptibility loci associated with kidney disease in type 1 diabetes
- 2012
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In: PLOS Genetics. - San Francisco, USA : Public Library of Science, PLOS. - 1553-7390 .- 1553-7404. ; 8:9, s. e1002921-
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Journal article (peer-reviewed)abstract
- Diabetic kidney disease, or diabetic nephropathy (DN), is a major complication of diabetes and the leading cause of end-stage renal disease (ESRD) that requires dialysis treatment or kidney transplantation. In addition to the decrease in the quality of life, DN accounts for a large proportion of the excess mortality associated with type 1 diabetes (T1D). Whereas the degree of glycemia plays a pivotal role in DN, a subset of individuals with poorly controlled T1D do not develop DN. Furthermore, strong familial aggregation supports genetic susceptibility to DN. However, the genes and the molecular mechanisms behind the disease remain poorly understood, and current therapeutic strategies rarely result in reversal of DN. In the GEnetics of Nephropathy: an International Effort (GENIE) consortium, we have undertaken a meta-analysis of genomewide association studies (GWAS) of T1D DN comprising similar to 2.4 million single nucleotide polymorphisms (SNPs) imputed in 6,691 individuals. After additional genotyping of 41 top ranked SNPs representing 24 independent signals in 5,873 individuals, combined meta-analysis revealed association of two SNPs with ESRD: rs7583877 in the AFF3 gene (P = 1.2 x 10(-8)) and an intergenic SNP on chromosome 15q26 between the genes RGMA and MCTP2, rs12437854 (P = 2.0 x 10(-9)). Functional data suggest that AFF3 influences renal tubule fibrosis via the transforming growth factor-beta (TGF-beta 1) pathway. The strongest association with DN as a primary phenotype was seen for an intronic SNP in the ERBB4 gene (rs7588550, P = 2.1 x 10(-7)), a gene with type 2 diabetes DN differential expression and in the same intron as a variant with cis-eQTL expression of ERBB4. All these detected associations represent new signals in the pathogenesis of DN.
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