Spectrum of congenital anomalies among VACTERL cases: a EUROCAT population-based study

Background: The VACTERL (Vertebral anomalies, Anal atresia, Cardiac malformations, Tracheo-Esophageal fistula, Renal anomalies, Limb abnormalities) association is the non-random occurrence of at least three of these congenital anomalies: vertebral, anal, cardiac, tracheo-esophageal, renal, and limb anomalies. Diagnosing VACTERL patients is difficult, as many disorders have multiple features in common with VACTERL. The aims of this study were to clearly outline component features, describe the phenotypic spectrum among the largest group of VACTERL patients thus far reported, and to identify phenotypically similar subtypes. Methods: A case-only study was performed assessing data on 501 cases recorded with VACTERL in the JRC-EUROCAT (Joint Research Centre-European Surveillance of Congenital Anomalies) central database (birth years: 1980–2015). We differentiated between major and minor VACTERL features and anomalies outside the VACTERL spectrum to create a clear definition of VACTERL. Results: In total, 397 cases (79%) fulfilled our VACTERL diagnostic criteria. The most commonly observed major VACTERL features were anorectal malformations and esophageal atresia/tracheo-esophageal fistula (both occurring in 62% of VACTERL cases), followed by cardiac (57%), renal (51%), vertebral (33%), and limb anomalies (25%), in every possible combination. Three VACTERL subtypes were defined: STRICT-VACTERL, VACTERL-LIKE, and VACTERL-PLUS, based on severity and presence of additional congenital anomalies. Conclusion: The clearly defined VACTERL component features and the VACTERL subtypes introduced will improve both clinical practice and etiologic research.acceptedVersio

Clinical, biochemical and genetic spectrum of 70 patients with ACAD9 deficiency: Is riboflavin supplementation effective?

Background: Mitochondrial acyl-CoA dehydrogenase family member 9 (ACAD9) is essential for the assembly of mitochondrial respiratory chain complex I. Disease causing biallelic variants in ACAD9 have been reported in individuals presenting with lactic acidosis and cardiomyopathy. Results: We describe the genetic, clinical and biochemical findings in a cohort of 70 patients, of whom 29 previously unpublished. We found 34 known and 18 previously unreported variants in ACAD9. No patients harbored biallelic loss of function mutations, indicating that this combination is unlikely to be compatible with life. Causal pathogenic variants were distributed throughout the entire gene, and there was no obvious genotype-phenotype correlation. Most of the patients presented in the first year of life. For this subgroup the survival was poor (50% not surviving the first 2 years) comparing to patients with a later presentation (more than 90% surviving 10 years). The most common clinical findings were cardiomyopathy (85%), muscular weakness (75%) and exercise intolerance (72%). Interestingly, severe intellectual deficits were only reported in one patient and

Bi-allelic Loss-of-Function CACNA1B Mutations in Progressive Epilepsy-Dyskinesia.

The occurrence of non-epileptic hyperkinetic movements in the context of developmental epileptic encephalopathies is an increasingly recognized phenomenon. Identification of causative mutations provides an important insight into common pathogenic mechanisms that cause both seizures and abnormal motor control. We report bi-allelic loss-of-function CACNA1B variants in six children from three unrelated families whose affected members present with a complex and progressive neurological syndrome. All affected individuals presented with epileptic encephalopathy, severe neurodevelopmental delay (often with regression), and a hyperkinetic movement disorder. Additional neurological features included postnatal microcephaly and hypotonia. Five children died in childhood or adolescence (mean age of death: 9 years), mainly as a result of secondary respiratory complications. CACNA1B encodes the pore-forming subunit of the pre-synaptic neuronal voltage-gated calcium channel Cav2.2/N-type, crucial for SNARE-mediated neurotransmission, particularly in the early postnatal period. Bi-allelic loss-of-function variants in CACNA1B are predicted to cause disruption of Ca2+ influx, leading to impaired synaptic neurotransmission. The resultant effect on neuronal function is likely to be important in the development of involuntary movements and epilepsy. Overall, our findings provide further evidence for the key role of Cav2.2 in normal human neurodevelopment.MAK is funded by an NIHR Research Professorship and receives funding from the Wellcome Trust, Great Ormond Street Children's Hospital Charity, and Rosetrees Trust. E.M. received funding from the Rosetrees Trust (CD-A53) and Great Ormond Street Hospital Children's Charity. K.G. received funding from Temple Street Foundation. A.M. is funded by Great Ormond Street Hospital, the National Institute for Health Research (NIHR), and Biomedical Research Centre. F.L.R. and D.G. are funded by Cambridge Biomedical Research Centre. K.C. and A.S.J. are funded by NIHR Bioresource for Rare Diseases. The DDD Study presents independent research commissioned by the Health Innovation Challenge Fund (grant number HICF-1009-003), a parallel funding partnership between the Wellcome Trust and the Department of Health, and the Wellcome Trust Sanger Institute (grant number WT098051). We acknowledge support from the UK Department of Health via the NIHR comprehensive Biomedical Research Centre award to Guy's and St. Thomas' National Health Service (NHS) Foundation Trust in partnership with King's College London. This research was also supported by the NIHR Great Ormond Street Hospital Biomedical Research Centre. J.H.C. is in receipt of an NIHR Senior Investigator Award. The research team acknowledges the support of the NIHR through the Comprehensive Clinical Research Network. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, Department of Health, or Wellcome Trust. E.R.M. acknowledges support from NIHR Cambridge Biomedical Research Centre, an NIHR Senior Investigator Award, and the University of Cambridge has received salary support in respect of E.R.M. from the NHS in the East of England through the Clinical Academic Reserve. I.E.S. is supported by the National Health and Medical Research Council of Australia (Program Grant and Practitioner Fellowship)

Evaluation of Array Comparative genomic Hybridisation in prenatal diagnosis of fetal anomalies: a multicentre cohort study with cost analysis and assessment of patient, health professional and commissioner preferences for array comparative genomic hybridisation

Background: Current pathways for testing fetuses at increased risk of a chromosomal anomaly because of an ultrasound anomaly involve karyotyping after rapid aneuploidy exclusion. Chromosomal microarray (CMA) may detect more clinically significant chromosomal imbalances than karyotyping but evidence to guide UK health service providers on whether or not CMA should replace karyotyping is limited. Objectives: (1) To compare detection rates of copy number variants (CNVs) and laboratory turnaround times (TATs) by karyotyping and CMA in fetuses with ultrasound anomalies, (2) to calculate test costs and the cost per additional pathogenic CNV detected by CMA relative to karyotyping and (3) to determine what factors influence parents’ and health professionals’ choice and decision-making about CMA. Design: A multicentre experimental research cohort study with an additional cost analysis. Setting: A total of 20 fetal medicine units and nine cytogenetic laboratories across England and Wales. Participants: Women with a fetus undergoing quantitative fluorescent polymerase chain reaction (QF-PCR) and karyotyping for clinical indications with (1) one or more structural anomalies identified on ultrasound or (2) an isolated nuchal translucency (NT) of ≥ 3.5 mm. Interventions: Karyotyping and CMA after exclusion of major chromosomal anomalies by QF-PCR. The array design consisted of 8-plex 60,000 60-mer oligonucleotides with a backbone resolution of ≈75 kb. Main outcome measures: Rates of abnormal karyotypes and pathogenic CNVs and variants of unknown significance on CMA. Laboratory TATs for karyotyping and CMA. Costs of karyotyping and CMA and cost per additional pathogenic CNV detected by CMA. Parent and health professional attitudes to CMA. Results: Out of the 1718 probands recruited, 1123 cases with normal QF-PCR and both karyotype and CMA were available for analysis. In the group with structural anomalies (n = 629), CMA detected more CNVs [6.8%, 95% confidence interval (CI) 4.4% to 9.3%] and more pathogenic CNVs (3.5%, 95% CI 1.5% to 5.5%) than karyotyping. In the increased NT group (n = 494), CMA detected more CNVs (4.5%, 95% CI 1.8% to 7.1%) than karyotyping but not more pathogenic CNVs. Compared with karyotyping, median TAT was 3 days [interquartile range (IQR) 0–13 days] longer with CMA but when actual set-up to reporting times were compared, CMA was 5 days (IQR 2–8 days) quicker. Cost calculations of the respective pathways indicated that, per patient, CMA is on average £113 more costly than karyotyping. The incremental cost per extra pathogenic CNV detected by CMA was greater in the increased NT than the structural anomaly group (£9439 vs. £3635). Qualitative evaluation suggested that parents find CMA acceptable, despite the uncertainties it may introduce, and that in the main it is acceptable to health professionals and commissioners. Conclusions: CMA is a robust, acceptable and probably cost-effective method to detect more clinically significant chromosomal imbalances in the anomalous fetus. The results suggest that CMA should replace karyotyping in these care pathways. Future work: The application of CMA (and exome sequencing) on cell-free DNA in maternal plasma. Trial registration: Current Controlled Trials ISRCTN01058191. Funding: This project was funded by the Efficacy and Mechanism Evaluation programme, a MRC and NIHR partnership. The funder had no role in the identification, design and conduct of the study and the reporting of the analysis. The funder did recommend the inclusion of the cell-free DNA aspects of the EACH study. Funding was also received from the Great Ormond Street Biomedical Research Centre

Causes of death in children with congenital anomalies up to age 10 in eight European countries

Background Congenital anomalies (CAs) increase the risk of death during infancy and childhood. This study aimed to evaluate the accuracy of using death certificates to estimate the burden of CAs on mortality for children under 10 years old.Methods Children born alive with a major CA between 1 January 1995 and 31 December 2014, from 13 population-based European CA registries were linked to mortality records up to their 10th birthday or 31 December 2015, whichever was earlier.Results In total 4199 neonatal, 2100 postneonatal and 1087 deaths in children aged 1–9 years were reported. The underlying cause of death was a CA in 71% (95% CI 64% to 78%) of neonatal and 68% (95% CI 61% to 74%) of postneonatal infant deaths. For neonatal deaths the proportions varied by registry from 45% to 89% and by anomaly from 53% for Down syndrome to 94% for tetralogy of Fallot. In children aged 1–9, 49% (95% CI 42% to 57%) were attributed to a CA. Comparing mortality in children with anomalies to population mortality predicts that over 90% of all deaths at all ages are attributable to the anomalies. The specific CA was often not reported on the death certificate, even for lethal anomalies such as trisomy 13 (only 80% included the code for trisomy 13).Conclusions Data on the underlying cause of death from death certificates alone are not sufficient to evaluate the burden of CAs on infant and childhood mortality across countries and over time. Linked data from CA registries and death certificates are necessary for obtaining accurate estimates