Evaluation of prenatal diagnosis of congenital heart diseases by ultrasound: experience from 20 European registries.

OBJECTIVES: To evaluate prenatal diagnosis of congenital heart diseases by ultrasound investigation in well-defined European populations. DESIGN: Data from 20 registries of congenital malformations in 12 European countries were included. The prenatal ultrasound screening programs in the countries ranged from no routine screening to three ultrasound investigations per patient routinely performed. RESULTS: There were 2454 cases with congenital heart disease with an overall prenatal detection rate of 25%. Termination of pregnancy was performed in 293 cases (12%). There was considerable variation in prenatal detection rate between regions, with the lowest detection rates being in countries without ultrasound screening (11%) and in Eastern European countries (Croatia, Lithuania and Ukraine; 8%). In Western European countries with ultrasound screening, detection rate ranged from 19-48%. There was a significant difference in prenatal detection rate and proportion of induced abortions between isolated congenital heart disease and congenital heart disease associated with chromosome anomalies, multiple malformations and syndromes (P < 0.0001). There were 1694 cases with isolated congenital heart disease of which 16% were diagnosed prenatally. Malformations affecting the size of the ventricles were detected prenatally in half of the cases. CONCLUSIONS: Prenatal detection rate of congenital heart disease varies significantly between countries even with the same screening recommendations. The presence of associated malformations significantly increases the prenatal detection rate.

Identification of heart rate-associated loci and their effects on cardiac conduction and rhythm disorders.

Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously established loci. Experimental downregulation of gene expression in Drosophila melanogaster and Danio rerio identified 20 genes at 11 loci that are relevant for heart rate regulation and highlight a role for genes involved in signal transmission, embryonic cardiac development and the pathophysiology of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate-increasing and heart rate-decreasing variants associate with risk of atrial fibrillation. Our findings provide fresh insights into the mechanisms regulating heart rate and identify new therapeutic targets.

Bax-induced apoptosis in Leber's congenital amaurosis : a dual role in rod and cone degeneration

Purpose:We previously observed that anti- and pro-apoptotic genes of the Bcl-2 family were differentially expressed during the development of LCA in the Rpe65-/- mouse model (Cottet et al. 2006). Moreover, we reported that activation and translocation of pro-apoptotic Bax to the mitochondria was associated with apoptosis of rod photoreceptors as the disease progressed (Cottet et al. 2008). In this study we challenged whether disruption of the pro-apoptotic pro-apoptotic Bax protein is sufficient to protect photoreceptor cells against apoptosis. Methods:Apoptosis of photoreceptor cells was addressed by TUNEL assay on flatmounted retinas. Counting of the rod nuclei within the ONL was performed following hematoxylin/eosin histological staining of retina sections. Expression level and localization of photoreceptor gene markers were assessed by quantitative PCR and immunohistological analyses. Results:While expression of rod photoreceptor genes was decreased in Rpe65-deficient retina, expression level remained unchanged in Rpe65-/- / Bax-/- mice. Moreover, OS dysorganization and shortening as well as decrease in ONL thickness observed in diseased retina were prevented in mice lacking functional Bax protein. TUNEL assay confirmed that Bax-dependent rod photoreceptor apoptosis was abolished in Rpe65-/- / Bax-/- mice. However, early and fast degeneration of cone cells was not prevented in Rpe65-/- / Bax-/- mice, indicating that Bax-induced apoptotic pathway was not involved in the degenerating process of cones in Rpe65-deficient retina. Conclusions:Altogether, these data show for the first time that a single genetic mutation can trigger two independent apoptotic pathways in rod and cone photoreceptors in LCA disease. While pro-apoptotic Bax is essential to trigger rod photoreceptor apoptosis, early degeneration of cones is not dependent on Bax-mediated apoptotic pathway in Rpe65-deficientmice.

Novel calmodulin mutations associated with congenital arrhythmia susceptibility.

BACKGROUND: Genetic predisposition to life-threatening cardiac arrhythmias such as congenital long-QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT) represent treatable causes of sudden cardiac death in young adults and children. Recently, mutations in calmodulin (CALM1, CALM2) have been associated with severe forms of LQTS and CPVT, with life-threatening arrhythmias occurring very early in life. Additional mutation-positive cases are needed to discern genotype-phenotype correlations associated with calmodulin mutations. METHODS AND RESULTS: We used conventional and next-generation sequencing approaches, including exome analysis, in genotype-negative LQTS probands. We identified 5 novel de novo missense mutations in CALM2 in 3 subjects with LQTS (p.N98S, p.N98I, p.D134H) and 2 subjects with clinical features of both LQTS and CPVT (p.D132E, p.Q136P). Age of onset of major symptoms (syncope or cardiac arrest) ranged from 1 to 9 years. Three of 5 probands had cardiac arrest and 1 of these subjects did not survive. The clinical severity among subjects in this series was generally less than that originally reported for CALM1 and CALM2 associated with recurrent cardiac arrest during infancy. Four of 5 probands responded to β-blocker therapy, whereas 1 subject with mutation p.Q136P died suddenly during exertion despite this treatment. Mutations affect conserved residues located within Ca(2+)-binding loops III (p.N98S, p.N98I) or IV (p.D132E, p.D134H, p.Q136P) and caused reduced Ca(2+)-binding affinity. CONCLUSIONS: CALM2 mutations can be associated with LQTS and with overlapping features of LQTS and CPVT.

Spectrum of congenital anomalies in pregnancies with pregestational diabetes.

BACKGROUND: Maternal pregestational diabetes is a well-known risk factor for congenital anomalies. This study analyses the spectrum of congenital anomalies associated with maternal diabetes using data from a large European database for the population-based surveillance of congenital anomalies. METHODS: Data from 18 population-based EUROCAT registries of congenital anomalies in 1990-2005. All malformed cases occurring to mothers with pregestational diabetes (diabetes cases) were compared to all malformed cases in the same registry areas to mothers without diabetes (non-diabetes cases). RESULTS: There were 669 diabetes cases and 92,976 non diabetes cases. Odds ratios in diabetes pregnancies relative to non-diabetes pregnancies comparing each EUROCAT subgroup to all other non-chromosomal anomalies combined showed significantly increased odds ratios for neural tube defects (anencephaly and encephalocele, but not spina bifida) and several subgroups of congenital heart defects. Other subgroups with significantly increased odds ratios were anotia, omphalocele and bilateral renal agenesis. Frequency of hip dislocation was significantly lower among diabetes (odds ratio 0.15, 95% CI 0.05-0.39) than non-diabetes cases. Multiple congenital anomalies were present in 13.6 % of diabetes cases and 6.1 % of non-diabetes cases. The odds ratio for caudal regression sequence was very high (26.40,95% CI 8.98-77.64), but only 17% of all caudal regression cases resulted from a pregnancy with pregestational diabetes. CONCLUSIONS: The increased risk of congenital anomalies in pregnancies with pregestational diabetes is related to specific non-chromosomal congenital anomalies and multiple congenital anomalies and not a general increased risk.

Congenital disorder of glycosylation type Id (CDG Id) : phenotypic, biochemical and molecular characterization of a new patient

Rapport de synthèseLes troubles de la glycosylation (Congenital Disorders of Glycosylation, CDG) regroupent une famille de maladies multi-systémiques héréditaires causées par des défauts dans la synthèse de glycoconjugés. La glycosylation est une réaction enzymatique consistant à lier de façon covalente un glucide à une chaîne peptidique ou une protéine. Il existe deux types de glycosylation. La N-gjycosylation est l'addition de glucides aux chaînes peptidiques en croissance dès leur entrée dans la lumière du réticulum endoplasmique. Elle s'effectue sur les futures glycoprotéines membranaires et conduit à des chaînes de sucres courtes et ramifiées. La O-glycosylation est l'addition de glucides au niveau des résidus hydroxylés des acides aminés sérine et thréonine des chaînes peptidiques déjà présentes dans la lumière de l'appareil de Golgi. Elle est, dans la plupart des cas, effectuée sur îes protéoglycanes et conduit à des chaînes de sucres longues et non ramifiées. La classification des CDG repose sur le niveau de l'étape limitante de la glycosylation. Les CDG de type 1, plus fréquents, regroupent les déficits enzymatiques se situant en amont du transfert de Poligosaccharide sur la chaîne peptidique. Les CDG de type 2 regroupent ceux ayant lieu en aval de ce transfert. Parmi les nombreux différents sous-types de CDG, le CDG de type ld est causé par une anomalie de la mannosyltransferase, enzyme codée par le gène ALG3 (chromosome 3q27). Jusqu'à ce jour, six patients atteints de CDG ld ont été reportés dans la littérature. Notre travail a permis de décrire un septième patient et d'affiner les caractéristiques cliniques, biologiques, neuroradiologiques et moléculaires du CDG ld. Notre patient est notamment porteur d'une nouvelle mutation de type missense sur le gène ALG3. Tous les patients atteints de CDG ld présentent une encéphalopathie progressive avec microcéphalie, retard psychomoteur sévère et épilepsie. Une ostéopénie marquée est présente chez certains patients. Elle est parfois sous diagnostiquée et révélée uniquement lors de fracture pathologique. Les patients atteints de CDG ld présentent également des traits dysmorphiques typiques, mais aucune atteinte multi-systémique ou anomalie biologique spécifique n'est retrouvée telle que dans les autres types de CDG. Le dépistage biochimique des troubles de la glycosylation se fait par une analyse simple et peu coûteuse qui est l'analyse de la transferrine sérique par isoelectrofocusing ou par électrophorèse capillaire. Un tel dépistage devrait être effectué chez tout patient présentant une encéphalopathie d'origine indéterminée, et cela même en l'absence d'atteinte multi- systémique. Notre travail a été publié sous forme d'article de type « short report », peer-reviewed, dans le Journal of Inherited Metabolic Diseases. Le Journal est une révue spécialisée du domaine des erreirs innées du métabolisme. S'agissant d'un seul patient rapporté, l'article ne montre que très synthétiquement le travail effectué, Pour cette raison un complément à l'article avec matériel, méthodes et résultats figure ci-après et concerne la partie de recherche moléculaire de notre travail. La doctorante a non seulement encadré personnellement le patient au niveau clinique et biochimique, mais a plus particulièrement mis au point l'analyse moléculaire du gène ALG3 dans le laboratoire de Pédiatrie Moléculaire pour la première fois ; cela a impliqué l'étude du gène, le choix des oligonucleotides et l'optimisation des réactions d'amplification et séquençage.

Congenital diaphragmatic hernia: current status and review of the literature.

Treatment of congenital diaphragmatic hernia (CDH) challenges obstetricians, pediatric surgeons, and neonatologists. Persistent pulmonary hypertension (PPHT) associated with lung hypoplasia in CDH leads to a high mortality rate at birth. PPHT is principally due to an increased muscularization of the arterioles. Management of CDH has been greatly improved by the introduction of prenatal surgical intervention with tracheal obstruction (TO) and by more appropriate postnatal care. TO appears to accelerate fetal lung growth and to increase the number of capillary vessels and alveoli. Improvement of postnatal care over the last years is mainly due to the avoidance of lung injury by applying low peak inflation pressure during ventilation. The benefits of other drugs or technical improvements such as the use of inhaled nitric oxide or extracorporeal membrane oxygenation (ECMO) are still being debated and no single strategy is accepted worldwide. Despite intensive clinical and experimental research, the treatment of newborn with CDH remains difficult.

Polymorphous Si thin films from radio frequency plasmas of SiH4 diluted in Ar: A study by transmission electron microscopy and Raman spectroscopy

In this study, we present a detailed structural characterization by means of transmission electron microscopy and Raman spectroscopy of polymorphous silicon (pm-Si:H) thin films deposited using radio-frequency dust-forming plasmas of SiH4 diluted in Ar. Square-wave modulation of the plasma and gas temperature was varied to obtain films with different nanostructures. Transmission electron microscopy and electron diffraction have shown the presence of Si crystallites of around 2 nm in the pm-Si:H films, which are related to the nanoparticles formed in the plasma gas phase coming from their different growth stages, named particle nucleation and coagulation. Raman scattering has proved the role of the film nanostructure in the crystallization process induced ¿in situ¿ by laser heating.

Ventilation-induced pulmonary vasodilatation in lambs with congenital diaphragmatic hernia is modulated by nitric oxide.

Endogenous nitric oxide (NO) mediates pulmonary vasodilatation at birth, but inhaled NO fails to reduce pulmonary vascular resistance (PVR) in newborns with congenital diaphragmatic hernia (CDH). This study was designed to investigate the effects of ventilation, and the nature of its endogenous mediator, in fetal lambs with experimental CDH. Investigations at 138 days of gestation showed that ventilation markedly decreased PVR. Inhibition of NO synthesis reduced ventilation-induced pulmonary vasodilatation in vivo and increased in vitro isometric tension of vascular rings. Ventilation therefore reduces PVR at birth in lambs with CDH, and endogenous NO seems to contribute to this reduction.

Toxoplasmosis during pregnancy and infancy. A new approach for Switzerland.

In recent years it has become evident that screening for and treatment of acute toxoplasmosis during pregnancy may have no measurable impact on vertical transmission and neonatal morbidity and mortality. A broad lack of evidence with regard to many aspects of congenital toxoplasmosis has been recognised in a common European initiative (EUROTOXO) which reviewed several thousand published papers on the subject of toxoplasmosis during pregnancy and childhood. It was therefore clear that the strategies currently implemented in our country would, on closer inspection, no longer withstand the claim for evidence-based procedures. The arguments and call for a change of paradigm in Switzerland which follow here are the result of a national consensus-finding process involving experts from various specialities, including gynaecology/obstetrics, paediatrics/neonatology, infectiology, ophthalmology and laboratory medicine, together with representatives of the public health authorities.