Higher risk of cerebral palsy, seizures/epilepsy, visual- and hearing impairments, cancer, injury and child abuse in children with congenital anomalies: Data from the EUROlinkCAT study

AIM

The aim is to examine the risk of cerebral palsy, seizures/epilepsy, visual- and hearing impairments, cancer, injury/poisoning and child abuse in children with and without a congenital anomaly up to age 5 and 10 years.

METHODS

This is a population-based data linkage cohort study linking information from the European Surveillance of Congenital Anomalies network (EUROCAT) and birth registries to hospital discharge databases. We included 91 504 live born children with major congenital anomalies born from 1995 to 2014 from nine EUROCAT registries in five countries and 1 960 727 live born children without congenital anomalies (reference children). Prevalence and relative risk (RR) were estimated for each of the co-morbidities using Kaplan-Meier survival estimates.

RESULTS

Children with congenital anomalies had higher risks of the co-morbidities than reference children. The prevalences in the reference children were generally very low. The RR was 13.8 (95% CI 12.5-15.1) for cerebral palsy, 2.5 (95% CI 2.4-2.6) for seizures/epilepsy, 40.8 (95% CI 33.2-50.2) for visual impairments, 10.0 (95% CI 9.2-10.9) for hearing loss, 3.6 (95% CI 3.2-4.2) for cancer, 1.5 (95% CI 1.4-1.5) for injuries/poisoning and 2.4 (95% CI 1.7-3.4) for child abuse.

CONCLUSION

Children with congenital anomalies were more likely to be diagnosed with the specified co-morbidities compared to reference children.

Surveillance of multiple congenital anomalies; searching for new associations

Many human teratogens are associated with a spectrum of congenital anomalies rather than a single defect, and therefore the identification of congenital anomalies occurring together more frequently than expected may improve the detection of teratogens. Thirty-two EUROCAT congenital anomaly registries covering 6,599,765 births provided 123,566 cases with one or more major congenital anomalies (excluding chromosomal and genetic syndromes) for the birth years 2008-2016. The EUROCAT multiple congenital anomaly algorithm identified 8804 cases with two or more major congenital anomalies in different organ systems, that were not recognized as part of a syndrome or sequence. For each pair of anomalies, the odds of a case having both anomalies relative to having only one anomaly was calculated and the p value was estimated using a two-sided Fisher's exact test. The Benjamini-Hochberg procedure adjusted p values to control the false discovery rate and pairs of anomalies with adjusted p values < 0.05 were identified. A total of 1386 combinations of two anomalies were analyzed. Out of the 31 statistically significant positive associations identified, 20 were found to be known associations or sequences already described in the literature and 11 were considered "potential new associations" by the EUROCAT Coding and Classification Committee. After a review of the literature and a detailed examination of the individual cases with the anomaly pairs, six pairs remained classified as new associations. In summary, systematically searching for congenital anomalies occurring together more frequently than expected using the EUROCAT database is worthwhile and has identified six new associations that merit further investigation.

Updated EUROCAT guidelines for classification of cases with congenital anomalies

BACKGROUND

Precise and correct classification of congenital anomalies is important in epidemiological studies, not only to classify according to etiology but also to group similar congenital anomalies together, to create homogeneous subgroups for surveillance and research. This paper presents the updated EUROCAT (European surveillance of congenital anomalies) subgroups of congenital anomalies and the updated multiple congenital anomaly (MCA) algorithm and provides the underlying arguments for the revisions.

METHODS

The EUROCAT methodology is described. In addition, we show how we validated the revised EUROCAT subgroups and MCA algorithm, which are both based on the International Classification of Diseases (ICD10/ICD9) codes.

RESULTS

The updated EUROCAT subgroups and the updated MCA algorithm are described in detail and the updated version is compared to the previous versions.

CONCLUSION

The EUROCAT subgroups and MCA algorithm provide a standardized and clear methodology for congenital anomaly research and epidemiological surveillance of congenital anomalies in order to facilitate the identification of teratogenic exposures and to assess the impact of primary prevention and prenatal screening policies. The EUROCAT subgroups and MCA algorithm are made freely available for other researchers via the EUROCAT Database Management Software.

Risk factors for mortality in infancy and childhood in children with major congenital anomalies: A European population-based cohort study

BACKGROUND

Preterm birth and young maternal age are known risk factors for infant and childhood mortality. There is limited knowledge of the impact of these risk factors in children born with major congenital anomalies (CAs), who have inherently higher risks of death compared with other children.

OBJECTIVES

To investigate the risk factors for mortality up to age 10 years in children born with specific major CAs.

METHODS

This population-based cohort study involved 150,198 livebirths from 1995 to 2014 in 13 European CA registries linked to mortality data. Cox proportional hazards models estimated the association of gestational age, maternal age and child's sex with death <1 year and 1-9 years for the whole cohort and by CA subgroup. Hazard ratios (HR) from each registry were pooled using multivariate meta-analysis.

RESULTS

Preterm birth had a dose-response association with mortality; compared with infants born at 37+ weeks gestation, those born at <28, 28-31 and 32-36 weeks had 14.88 (95% CI 12.57, 17.62), 8.39 (95% CI 7.16, 9.85) and 3.88 (95% CI 3.40, 4.43) times higher risk of death <1 year, respectively. The corresponding risks at 1-9 years were 4.99 (95% CI 2.94, 8.48), 3.09 (95% CI 2.28, 4.18) and 2.04 (95% CI 1.69, 2.46) times higher, respectively. Maternal age <20 years (versus 20-34 years) was a risk factor for death <1 year (HR 1.30, 95% CI 1.09, 1.54) and 1-9 years (HR 1.58, 95% CI 1.19, 2.10). Females had 1.22 (95% CI 1.07, 1.39) times higher risk of death between 1 and 9 years than males.

CONCLUSION

Preterm birth was associated with considerably higher infant and childhood mortality in children with CAs, comparable to estimates reported elsewhere for the background population. Additional risk factors included young maternal age and female sex. Information on risk factors could benefit clinical care and guide counselling of parents following CA diagnoses.

The burden of disease for children born alive with Turner syndrome-A European cohort study

BACKGROUND

Turner syndrome is a rare congenital anomaly caused by complete or partial X chromosome monosomy that may affect mortality and morbidity in childhood.

METHODS

This population-based data-linkage cohort study, as part of the EUROlinkCAT project, investigated mortality and morbidity for the first 5 years of life for liveborn European children diagnosed with Turner syndrome. Thirteen population-based registries in 10 countries from the European surveillance of congenital anomalies (EUROCAT) network participated. Data on children born 1995-2014 and diagnosed with Turner syndrome were linked to mortality, hospital and prescription records. Children with any congenital anomaly and children without a congenital anomaly were included for comparison on morbidity.

RESULTS

Out of a population of 5.8 million livebirths 404 were diagnosed with Turner syndrome prenatally or in infancy and 95.5% survived to their fifth birthday. During the first year of life 72.3% (95% CI 59.5;81.6) of children with Turner syndrome were hospitalized, the median length of stay was 5.6 days (95% CI 3.5;7.7) and 18.7% (95% CI 13.9;23.9) underwent surgery. After the first year of life hospitalizations and length of stay decreased but more children underwent surgery (30.8% [95% CI 17.6;44.7]). In the first 5 years the percentage of children with Turner syndrome having a prescription for antibiotics was 12%-20% per year and increased with the age of child.

CONCLUSIONS

In the first year of life, the burden of disease was relatively high for children with Turner syndrome. The outlook is more positive beyond the first year, though overall morbidity still exceeded that of children without congenital anomalies.

Creating a population-based cohort of children born with and without congenital anomalies using birth data matched to hospital discharge databases in 11 European regions: Assessment of linkage success and data quality

Linking routinely collected healthcare administrative data is a valuable method for conducting research on morbidity outcomes, but linkage quality and accuracy needs to be assessed for bias as the data were not collected for research. The aim of this study was to describe the rates of linking data on children with and without congenital anomalies to regional or national hospital discharge databases and to evaluate the quality of the matched data. Eleven population-based EUROCAT registries participated in a EUROlinkCAT study linking data on children with a congenital anomaly and children without congenital anomalies (reference children) born between 1995 and 2014 to administrative databases including hospital discharge records. Odds ratios (OR), adjusted by region, were estimated to assess the association of maternal and child characteristics on the likelihood of being matched. Data on 102,654 children with congenital anomalies were extracted from 11 EUROCAT registries and 2,199,379 reference children from birth registers in seven regions. Overall, 97% of children with congenital anomalies and 95% of reference children were successfully matched to administrative databases. Information on maternal age, multiple birth status, sex, gestational age and birthweight were >95% complete in the linked datasets for most regions. Compared with children born at term, those born at ≤27 weeks and 28-31 weeks were less likely to be matched (adjusted OR 0.23, 95% CI 0.21-0.25 and adjusted OR 0.75, 95% CI 0.70-0.81 respectively). For children born 32-36 weeks, those with congenital anomalies were less likely to be matched (adjusted OR 0.78, 95% CI 0.71-0.85) while reference children were more likely to be matched (adjusted OR 1.28, 95% CI 1.24-1.32). Children born to teenage mothers and mothers ≥35 years were less likely to be matched compared with mothers aged 20-34 years (adjusted ORs 0.92, 95% CI 0.88-0.96; and 0.87, 95% CI 0.86-0.89 respectively). The accuracy of linkage and the quality of the matched data suggest that these data are suitable for researching morbidity outcomes in most regions/countries. However, children born preterm and those born to mothers aged <20 and ≥35 years are less likely to be matched. While linkage to administrative databases enables identification of a reference group and long-term outcomes to be investigated, efforts are needed to improve linkages to population groups that are less likely to be linked.

Maternal age and the prevalence of congenital heart defects in Europe, 1995-2015: A register-based study

BACKGROUND

Evidence on the direction and strength of association between maternal age and the prevalence of congenital heart defects (CHD) in different age group categories is conflicting. Some studies have illustrated different trends with an increase in prevalence in younger and older age groups while other studies have reported a linear relationship. Given the increase in maternal age over recent years, it is important to study the CHD prevalence by maternal age.

OBJECTIVES

To examine the association between maternal age and the prevalence of CHD in Europe between 1995 and 2015 using population-based data from 24 registries belonging to the European Surveillance of Congenital Anomalies (EUROCAT) network.

METHODS

Associations over time of all nonsyndromic CHD according to maternal age category and for three CHD severity groupings (severity group I: very severe; severity group II: severe; severity group III: less severe) were examined using Bayesian multilevel Poisson regression modeling. Further subgroup analyses were undertaken within four maternal age-bands: ≤24, 25-29, 30-34 and 35-44 years. Descriptive summaries are also presented.

RESULTS

There were 51,608 nonsyndromic CHD cases in Europe over the 20-year study period. Total prevalence for all CHD combined was increased for younger mothers (≤24 years) and for mothers 35-44 years of age when compared with mothers aged 25-29 years (reference group) (IRR: 1.05, 95% CI: 1.02, 1.07). The total prevalence was increased for severity group I (very severe) only for younger mothers compared to those aged 25-29 years (IRR: 1.14, 95% CI: 1.04, 1.23). We found an increased prevalence of the following CHD subtypes: double outlet right ventricle (IRR:1.33, 95% CI: 1.09, 1.60), hypoplastic left heart syndrome (IRR: 1.18, 95% CI: 1.05, 1.32), hypoplastic right heart syndrome (IRR: 1.41, 95% CI: 1.05, 1.84), atrioventricular septal defect (IRR: 1.15, 95% CI: 1.01, 1.32), coarctation of aorta (IRR: 1.15, 95% CI: 1.03, 1.28) and atrial septal defect (IRR: 1.08, 95% CI: 1.02, 1.13). For older mothers (35-44 years) compared to the reference category, we observed an increased risk in the prevalence for severity group II (IRR: 1.09, 95% CI: 1.03, 1.14), severity group III (IRR: 1.05, 95% CI: 1.01, 1.08) and an increased prevalence of the CHD subtypes: Pulmonary valve stenosis (IRR: 1.22, 95% CI: 1.09, 1.34), ASD (IRR: 1.07, 95% CI: 1.02, 1.13), CoA (IRR: 1.18, 95% CI: 1.06, 1.32) and Tetralogy of Fallot (IRR: 1.14, 95% CI: 1.01, 1.28). Finally, for all age categories compared to the reference category, different associations of ASD and an increased prevalence of CoA was also observed.

CONCLUSIONS

Based on data for cases of CHD from 24 European population-based registries, evidence of a positive association between maternal age and the total prevalence of CHD for younger (≤24 years old) and older (35-44 years old) mothers was observed. The results suggest that young maternal age (≤24 years old) is a factor associated with severe CHD phenotypes while a positive association between advanced maternal age (35-44 years old) and mild CHD phenotypes was observed.

Amniotic band syndrome and limb body wall complex in Europe 1980-2019

Amniotic band syndrome (ABS) and limb body wall complex (LBWC) have an overlapping phenotype of multiple congenital anomalies and their etiology is unknown. We aimed to determine the prevalence of ABS and LBWC in Europe from 1980 to 2019 and to describe the spectrum of congenital anomalies. In addition, we investigated maternal age and multiple birth as possible risk factors for the occurrence of ABS and LBWC. We used data from the European surveillance of congenital anomalies (EUROCAT) network including data from 30 registries over 1980-2019. We included all pregnancy outcomes, including live births, stillbirths, and terminations of pregnancy for fetal anomalies. ABS and LBWC cases were extracted from the central EUROCAT database using coding information responses from the registries. In total, 866 ABS cases and 451 LBWC cases were included in this study. The mean prevalence was 0.53/10,000 births for ABS and 0.34/10,000 births for LBWC during the 40 years. Prevalence of both ABS and LBWC was lower in the 1980s and higher in the United Kingdom. Limb anomalies and neural tube defects were commonly seen in ABS, whereas in LBWC abdominal and thoracic wall defects and limb anomalies were most prevalent. Twinning was confirmed as a risk factor for both ABS and LBWC. This study includes the largest cohort of ABS and LBWC cases ever reported over a large time period using standardized EUROCAT data. Prevalence, clinical characteristics, and the phenotypic spectrum are described, and twinning is confirmed as a risk factor.

Accuracy of congenital anomaly coding in live birth children recorded in European health care databases, a EUROlinkCAT study

Electronic health care databases are increasingly being used to investigate the epidemiology of congenital anomalies (CAs) although there are concerns about their accuracy. The EUROlinkCAT project linked data from eleven EUROCAT registries to electronic hospital databases. The coding of CAs in electronic hospital databases was compared to the (gold standard) codes in the EUROCAT registries. For birth years 2010-2014 all linked live birth CA cases and all children identified in the hospital databases with a CA code were analysed. Registries calculated sensitivity and Positive Predictive Value (PPV) for 17 selected CAs. Pooled estimates for sensitivity and PPV were then calculated for each anomaly using random effects meta-analyses. Most registries linked more than 85% of their cases to hospital data. Gastroschisis, cleft lip with or without cleft palate and Down syndrome were recorded in hospital databases with high accuracy (sensitivity and PPV ≥ 85%). Hypoplastic left heart syndrome, spina bifida, Hirschsprung's disease, omphalocele and cleft palate showed high sensitivity (≥ 85%), but low or heterogeneous PPV, indicating that hospital data was complete but may contain false positives. The remaining anomaly subgroups in our study, showed low or heterogeneous sensitivity and PPV, indicating that the information in the hospital database was incomplete and of variable validity. Electronic health care databases cannot replace CA registries, although they can be used as an additional ascertainment source for CA registries. CA registries are still the most appropriate data source to study the epidemiology of CAs.

Bi-allelic variants in WNT7B disrupt the development of multiple organs in humans

BACKGROUND

Pulmonary hypoplasia, Diaphragmatic anomalies, Anophthalmia/microphthalmia and Cardiac defects delineate the PDAC syndrome. We aim to identify the cause of PDAC syndrome in patients who do not carry pathogenic variants in RARB and STRA6, which have been previously associated with this disorder.

METHODS

We sequenced the exome of patients with unexplained PDAC syndrome and performed functional validation of candidate variants.

RESULTS

We identified bi-allelic variants in WNT7B in fetuses with PDAC syndrome from two unrelated families. In one family, the fetus was homozygous for the c.292C>T (p.(Arg98*)) variant whereas the fetuses from the other family were compound heterozygous for the variants c.225C>G (p.(Tyr75*)) and c.562G>A (p.(Gly188Ser)). Finally, a molecular autopsy by proxy in a consanguineous couple that lost two babies due to lung hypoplasia revealed that both parents carry the p.(Arg98*) variant. Using a WNT signalling canonical luciferase assay, we demonstrated that the identified variants are deleterious. In addition, we found that wnt7bb mutant zebrafish display a defect of the swimbladder, an air-filled organ that is a structural homolog of the mammalian lung, suggesting that the function of WNT7B has been conserved during evolution for the development of these structures.

CONCLUSION

Our findings indicate that defective WNT7B function underlies a form of lung hypoplasia that is associated with the PDAC syndrome, and provide evidence for involvement of the WNT-β-catenin pathway in human lung, tracheal, ocular, cardiac, and renal development.

Epidemiology of aplasia cutis congenita: A population-based study in Europe

BACKGROUND

Aplasia cutis congenita (ACC) is a rare congenital anomaly characterized by localized or widespread absence of skin at birth, mainly affecting the scalp. Most information about ACC exists as individual case reports and medium-sized studies.

OBJECTIVES

This study aimed to investigate the epidemiology of ACC, using data from a large European network of population-based registries for congenital anomalies (EUROCAT).

METHODS

Twenty-eight EUROCAT population-based registries in 16 European countries were involved. Poisson regression models were exploited to estimate the overall and live birth prevalence, to test time trends in prevalence between four 5-year periods and to evaluate the impact of the change of coding for ACC from the unspecific ICD9-BPA code to the specific ICD10 code. Proportions of ACC cases associated with other anomalies were reported.

RESULTS

Five hundred cases were identified in the period 1998-2017 (prevalence: 5.10 per 100,000 births). Prevalence across 5-year periods did not differ significantly and no significant differences were evident due to the change from ICD9 to ICD10 in ACC coding. Heterogeneity in prevalence was observed across registries. The scalp was the most common site for ACC (96.4%) and associated congenital anomalies were present in 33.8% of cases. Patau and Adams-Oliver syndromes were the most frequent among the associated chromosomal anomalies (88.3%) and the associated genetic syndromes (57.7%), respectively. 16% of cases were associated with limb anomalies and 15.4% with congenital heart defects. A family history of ACC was found in 2% of cases.

CONCLUSION

To our knowledge, this is the only population-based study on ACC. The EUROCAT methodologies provide reliable prevalence estimates and proportions of associated anomalies.

European study showed that children with congenital anomalies often underwent multiple surgical procedures at different ages across Europe

AIM

Children with congenital anomalies often require surgery but data on the burden of surgery for these children are limited.

METHODS

A population-based record-linkage study in Finland, Wales and regions of Denmark, England, Italy and Spain. A total of 91 504 children with congenital anomalies born in 1995-2014 were followed to their tenth birthday or the end of 2015. Electronic linkage to hospital databases provided data on inpatient surgical procedures and meta-analyses of surgical procedures were performed by age groups.

RESULTS

The percentage of children having surgery in the first year was 38% with some differences across regions and 14% also underwent surgery at age 1-4 years. Regional differences in age at the time of their first surgical procedure were observed for children with cleft palate, hydronephrosis, hypospadias, clubfoot and craniosynostosis. The children had a median of 2.0 (95% CI 1.98, 2.02) surgical procedures before age 5 years with children with oesophageal atresia having the highest median number of procedures (4.5; 95% CI 3.3, 5.8).

CONCLUSION

A third of children with congenital anomalies required surgery during infancy and often more than one procedure was needed before age 5 years. There was no European consensus on the preferred age for surgery for some anomalies.

Prevalence of vascular disruption anomalies and association with young maternal age: A EUROCAT study to compare the United Kingdom with other European countries

BACKGROUND

Younger mothers are at a greater risk of having a pregnancy with gastroschisis and the risk is higher in the United Kingdom than other European countries. Gastroschisis is thought to be a vascular disruption anomaly and the aim of this study was to analyze the prevalence of other possible vascular disruption anomalies to determine whether both the younger maternal age and the UK associations also occur with these anomalies.

METHODS

All pregnancies with anomalies considered potentially due to vascular disruption from January 1, 2005 to December 31, 2017 from 26 European population-based congenital anomaly registries who were members of EUROCAT were analyzed. Multilevel models were used to allow for differences between registries when analyzing associations with maternal age, year of birth and whether the registry was in the United Kingdom.

RESULTS

There were 5,220 cases with potential vascular disruption anomalies, excluding chromosomal and genetic conditions, with a prevalence of 8.85 per 10,000 births in the United Kingdom and 5.44 in the other European countries. The prevalence per 10,000 births of gastroschisis (4.45 vs. 1.56) and congenital constriction bands (0.83 vs. 0.42) was significantly higher in the United Kingdom, even after adjusting for maternal age. However, transverse limb reduction defects had a similar prevalence (2.16 vs. 2.14 per 10,000). The expected increased prevalence in younger mothers was observed for vascular disruption anomalies overall and for the individual anomalies: gastroschisis and congenital constriction bands.

CONCLUSION

Vascular disruption anomalies that had an increased risk for younger mothers (such as gastroschisis) had a higher maternal age standardized prevalence in the United Kingdom, while vascular disruption anomalies with weaker associations with younger mothers (such as transverse limb reduction defects) did not have an increased prevalence in the United Kingdom, which may indicate a different etiology for these anomalies.

Prevalence of congenital heart defects in Europe, 2008-2015: A registry-based study

BACKGROUND

The total prevalence of congenital heart defects (CHDs) varies by populations and over time. Studies that examine trends in the prevalence of CHD in different regions may shed light on our understanding of the occurrence of CHD and the impact of different risk factors.

OBJECTIVES

To examine trends in total and live birth prevalence of nonsyndromic CHD in Europe between the years 2008 and 2015 and to investigate if the decreasing trend reported by previous studies is continuing.

METHODS

Cases of CHD delivered between January 1, 2008 and December 31, 2015 notified to 25 population-based EUROCAT (European Surveillance of Congenital Anomalies) registries in 14 countries, formed the population-based case-series. Prevalence (total/live) rates and 95% confidence intervals were calculated as the number of cases per 10,000 births (live and stillbirths). Time trends in prevalence of all nonsyndromic CHDs and for three CHD severity groups (very severe, severe, and less severe) were plotted using a Poisson regression multilevel approach.

RESULTS

The total prevalence of nonsyndromic CHD was 57.1 per 10,000 births (live births and stillbirths) for the 8-year period and remained stable across the three CHD severity groups while the live birth prevalence was 60.2 per 10,000 births. There was considerable variation in the reported total CHD prevalence and the direction of trends by registry. A decreasing prevalence of CHD was observed for the Norway and England/Wales registries, whereas the CHD prevalence increased for registries in Italy and Croatia.

CONCLUSIONS

The total prevalence of CHD in Europe between the years 2008 and 2015 remained stable for all CHD and across the three CHD severity groups. The decreasing trend reported by previous studies has not continued. However, we found significant differences in the total and live birth prevalence by registry.

Temporal and geographical variations in survival of children born with congenital anomalies in Europe: A multi-registry cohort study

BACKGROUND

Congenital anomalies are a major cause of perinatal, neonatal and infant mortality.

OBJECTIVES

The aim was to investigate temporal changes and geographical variation in survival of children with major congenital anomalies (CA) in different European areas.

METHODS

In this population-based linkage cohort study, 17 CA registries members of EUROCAT, the European network for the surveillance of CAs, successfully linked data on 115,219 live births with CAs to mortality records. Registries estimated Kaplan-Meier survival at 28 days and 5 years of age and fitted Cox's proportional hazards models comparing mortality at 1 year and 1-9 years of age for children born during 2005-2014 with those born during 1995-2004. The hazard ratios (HR) from each registry were combined centrally using a random-effects model. The 5-year survival conditional on having survived to 28 days of age was calculated.

RESULTS

The overall risk of death by 1 year of age for children born with any major CA in 2005-2014 decreased compared to 1995-2004 (HR 0.68, 95% confidence interval [CI] 0.53, 0.89). Survival at 5 years of age ranged between registries from 97.6% to 87.0%. The lowest survival was observed for the registry of OMNI-Net (Ukraine) (87.0%, 95% CI 86.1, 87.9).

CONCLUSIONS

Survival of children with CAs improved for births in 2005-2014 compared with 1995-2004. The use of CA registry data linked to mortality data enables investigation of survival of children with CAs. Factors such as defining major CAs, proportion of terminations of pregnancy for foetal anomaly, source of mortality data and linkage methods are important to consider in the design of future studies and in the interpretation of the results on survival of children with CAs.

Identifying phenotypic expansions for congenital diaphragmatic hernia plus (CDH+) using DECIPHER data

Congenital diaphragmatic hernia (CDH) can occur in isolation or in conjunction with other birth defects (CDH+). A molecular etiology can only be identified in a subset of CDH cases. This is due, in part, to an incomplete understanding of the genes that contribute to diaphragm development. Here, we used clinical and molecular data from 36 individuals with CDH+ who are cataloged in the DECIPHER database to identify genes that may play a role in diaphragm development and to discover new phenotypic expansions. Among this group, we identified individuals who carried putatively deleterious sequence or copy number variants affecting CREBBP, SMARCA4, UBA2, and USP9X. The role of these genes in diaphragm development was supported by their expression in the developing mouse diaphragm, their similarity to known CDH genes using data from a previously published and validated machine learning algorithm, and/or the presence of CDH in other individuals with their associated genetic disorders. Our results demonstrate how data from DECIPHER, and other public databases, can be used to identify new phenotypic expansions and suggest that CREBBP, SMARCA4, UBA2, and USP9X play a role in diaphragm development.

Hospital length of stay among children with and without congenital anomalies across 11 European regions—A population-based data linkage study

Background

Congenital anomalies are a leading cause of childhood morbidity, but little is known about the long-term outcomes.

Objective

To quantify the burden of disease in childhood for children with congenital anomalies by assessing the risk of hospitalisation, the number of days spent in hospital and proportion of children with extended stays (≥10 days).

Methods

European population-based record-linkage study in 11 regions in eight countries including children with congenital anomalies (EUROCAT children) and without congenital anomalies (reference children) living in the same regions. The children were born between 1995 and 2014 and were followed to their tenth birthday or 31/12/2015. European meta-analyses of the outcome measures were performed by two age groups, <1 year and 1–4 years.

Results

99,416 EUROCAT children and 2,021,772 reference children were linked to hospital databases. Among EUROCAT children, 85% (95%-CI: 79–90%) were hospitalised in the first year and 56% (95%-CI: 51–61%) at ages 1–4 years, compared to 31% (95%-CI: 26–37%) and 25% (95%-CI: 19–31%) of the reference children. Median length of stay was 2–3 times longer for EUROCAT children in both age groups. The percentages of children with extended stays (≥10 days) in the first year were 24% (95%-CI: 20–29%) for EUROCAT children and 1% (95%-CI: 1–2%) for reference children. The median length of stay varied greatly between congenital anomaly subgroups, with children with gastrointestinal anomalies and congenital heart defects having the longest stays.

Conclusions

Children with congenital anomalies were more frequently hospitalised and median length of stay was longer. The outlook improves after the first year. Parents of children with congenital anomalies should be informed about the increased hospitalisations required for their child’s care and the impact on family life and siblings, and they should be adequately supported.

Survival of children with rare structural congenital anomalies: a multi-registry cohort study

BACKGROUND

Congenital anomalies are the leading cause of perinatal, neonatal and infant mortality in developed countries. Large long-term follow-up studies investigating survival beyond the first year of life in children with rare congenital anomalies are costly and sufficiently large standardized cohorts are difficult to obtain due to the rarity of some anomalies. This study aimed to investigate the survival up to 10 years of age of children born with a rare structural congenital anomaly in the period 1995-2014 in Western Europe.

METHODS

Live births from thirteen EUROCAT (European network for the epidemiological surveillance of congenital anomalies) population-based registries were linked to mortality records. Survival for 12,685 live births with one of the 31 investigated rare structural congenital anomalies (CAs) was estimated at 1 week, 4 weeks and 1, 5 and 10 years of age within each registry and combined across Europe using random effects meta-analyses. Differences between registries were evaluated for the eight rare CAs with at least 500 live births.

RESULTS

Amongst the investigated CAs, arhinencephaly/holoprosencephaly had the lowest survival at all ages (58.1%, 95% Confidence Interval (CI): 44.3-76.2% at 1 week; 47.4%, CI: 36.4-61.6% at 1 year; 35.6%, CI: 22.2-56.9% at 10 years). Overall, children with rare CAs of the digestive system had the highest survival (> 95% at 1 week, > 84% at 10 years). Most deaths occurred within the first four weeks of life, resulting in a 10-year survival conditional on surviving 4 weeks of over 95% for 17 out of 31 rare CAs. A moderate variability in survival between participating registries was observed for the eight selected rare CAs.

CONCLUSIONS

Pooling standardised data across 13 European CA registries and the linkage to mortality data enabled reliable survival estimates to be obtained at five ages up to ten years. Such estimates are useful for clinical practice and parental counselling.

Ten-Year Survival of Children With Congenital Anomalies: A European Cohort Study

OBJECTIVES

To investigate the survival up to age 10 for children born alive with a major congenital anomaly (CA).

METHODS

This population-based linked cohort study (EUROlinkCAT) linked data on live births from 2005 to 2014 from 13 European CA registries with mortality data. Pooled Kaplan-Meier survival estimates up to age 10 were calculated for these children (77 054 children with isolated structural anomalies and 4011 children with Down syndrome).

RESULTS

The highest mortality of children with isolated structural CAs was within infancy, with survival of 97.3% (95% confidence interval [CI]: 96.6%-98.1%) and 96.9% (95% CI: 96.0%-97.7%) at age 1 and 10, respectively. The 10-year survival exceeded 90% for the majority of specific CAs (27 of 32), with considerable variations between CAs of different severity. Survival of children with a specific isolated anomaly was higher than in all children with the same anomaly when those with associated anomalies were included. For children with Down syndrome, the 10-year survival was significantly higher for those without associated cardiac or digestive system anomalies (97.6%; 95% CI: 96.5%-98.7%) compared with children with Down syndrome associated with a cardiac anomaly (92.3%; 95% CI: 89.4%-95.3%), digestive system anomaly (92.8%; 95% CI: 87.7%-98.2%), or both (88.6%; 95% CI: 83.2%-94.3%).

CONCLUSIONS

Ten-year survival of children born with congenital anomalies in Western Europe from 2005 to 2014 was relatively high. Reliable information on long-term survival of children born with specific CAs is of major importance for parents of these children and for the health care professionals involved in their care.

Epidemiology of Pierre-Robin sequence in Europe: A population-based EUROCAT study

BACKGROUND

Pierre Robin sequence (PRS) is a rare congenital anomaly. Respiratory disorders and feeding difficulties represent the main burden.

OBJECTIVE

The aim of this study was to investigate the epidemiology of PRS using a cohort of cases from EUROCAT, the European network of population-based registries of congenital anomalies.

METHODS

We analysed cases of PRS born in the period 1998-2017 collected by 29 population-based congenital anomaly registries in 17 different countries. We calculated prevalence estimates, prenatal detection rate, survival up to 1 week, and proportions of associated anomalies. The effect of maternal age was tested using a Poisson regression model.

RESULTS

Out of 11 669 155 surveyed births, a total of 1294 cases of PRS were identified. The estimate of the overall prevalence was 12.0 per 100 000 births (95% CI 9.9, 14.5). There was a total of 882 (68.2%) isolated cases, and the prevalence was 7.8 per 100 000 births (95% CI 6.7, 9.2). A total of 250 cases (19.3%) were associated with other structural congenital anomalies, 77 cases (6.0%) were associated with chromosomal anomalies and 77 (6.0%) with genetic syndromes. The prenatal detection rate in isolated cases was 12.0% (95% CI 9.8, 14.5) and increased to 16.0% (95% CI 12.7, 19.7) in the sub-period 2008-2017. The prevalence rate ratio of non-chromosomal cases with maternal age ≥35 was higher than in cases with maternal age <25 for total (PRR 1.26, 95% CI 1.05, 1.51) and isolated cases (PRR 1.33, 95% CI 1.00, 1.64). Survival of chromosomal cases (94.2%) and multiple anomaly cases (95.3%) were lower than survival of isolated cases (99.4%).

CONCLUSIONS

This epidemiological study using a large series of cases of PRS provides insights into the epidemiological profile of PRS in Europe. We observed an association with higher maternal age, but further investigations are needed to test potential risk factors for PRS.

Linking a European cohort of children born with congenital anomalies to vital statistics and mortality records: A EUROlinkCAT study

EUROCAT is a European network of population-based congenital anomaly (CA) registries. Twenty-one registries agreed to participate in the EUROlinkCAT study to determine if reliable information on the survival of children born with a major CA between 1995 and 2014 can be obtained through linkage to national vital statistics or mortality records. Live birth children with a CA could be linked using personal identifiers to either their national vital statistics (including birth records, death records, hospital records) or to mortality records only, depending on the data available within each region. In total, 18 of 21 registries with data on 192,862 children born with congenital anomalies participated in the study. One registry was unable to get ethical approval to participate and linkage was not possible for two registries due to local reasons. Eleven registries linked to vital statistics and seven registries linked to mortality records only; one of the latter only had identification numbers for 78% of cases, hence it was excluded from further analysis. For registries linking to vital statistics: six linked over 95% of their cases for all years and five were unable to link at least 85% of all live born CA children in the earlier years of the study. No estimate of linkage success could be calculated for registries linking to mortality records. Irrespective of linkage method, deaths that occurred during the first week of life were over three times less likely to be linked compared to deaths occurring after the first week of life. Linkage to vital statistics can provide accurate estimates of survival of children with CAs in some European countries. Bias arises when linkage is not successful, as early neonatal deaths were less likely to be linked. Linkage to mortality records only cannot be recommended, as linkage quality, and hence bias, cannot be assessed.

Prenatal chromosome microarray: 'The UK experience'. A survey of reporting practices in UK genetic services (2012-2019)

BACKGROUND

The value of chromosome microarray (CMA) in the prenatal detection of significant chromosome anomalies is well-established. To guide the introduction of this technique in routine clinical practice, the Joint Committee on Genomics in Medicine developed national UK guidelines for reporting prenatal CMA in 2015.

OBJECTIVE

To evaluate the UK experience of utilising prenatal CMA.

METHOD

A 36-item survey was distributed to all UK clinical genetics services (n = 23) in March 2019 requesting information pertaining to experience since diagnostic testing commenced and current practice (March 2018 to March 2019).

RESULTS

Eighteen UK genetics services currently offer prenatal CMA. A total of 14,554 tests had been performed. A pathogenic copy number variant was identified in 7.8% of tests overall, though the diagnostic rate increased to 8.4% in the final year of the survey. Variants of uncertain significance (VUS) were reported in 0.7% of tests, and 'actionable' incidental findings in 0.12%.

CONCLUSION

Diagnostic rate has improved over time, while reporting of VUS has decreased. Reviewing survey responses at a national level highlights variation in testing experience and practice, raising considerations both for future guideline development and implementation of other novel techniques including prenatal whole exome sequencing.

A hemizygous mutation in the FOXP3 gene (IPEX syndrome) resulting in recurrent X-linked fetal hydrops: a case report

Background

Fetal hydrops is excessive extravasation of fluid into the third space in a fetus, which could be due to a wide differential of underlying pathology. IPEX (immune dysregulation, polyendocrinopathy, enteropathy, X-linked) syndrome primarily affects males. It is a monogenic primary immunodeficiency syndrome of X-linked recessive inheritance due to FOXP3 gene variants. It is characterised by the development of multiple autoimmune disorders in affected individuals.

Case presentation

We present a rare cause of male fetal hydrops in the context of IPEX syndrome and discuss FOXP3 gene variants as a differential for ‘unexplained’ fetal hydrops that may present after the first trimester.

Discussion and conclusions

In all similar cases, the pathological process begins during intrauterine life. Furthermore, there are no survivors described. Consequently, this variant should be considered as a severe one, associated with intrauterine life onset and fatal course, i.e., the most severe IPEX phenotype.

Prevention of Neural Tube Defects in Europe: A Public Health Failure

Objective: Thirty years ago it was demonstrated that folic acid taken before pregnancy and in early pregnancy reduced the risk of a neural tube defect (NTD). Despite Public Health Initiatives across Europe recommending that women take 0.4 mg folic acid before becoming pregnant and during the first trimester, the prevalence of NTD pregnancies has not materially decreased in the EU since 1998, in contrast to the dramatic fall observed in the USA. This study aimed to estimate the number of NTD pregnancies that would have been prevented if flour had been fortified with folic acid in Europe from 1998 as it had been in the USA. Design and Setting: The number of NTD pregnancies from 1998 to 2017 that would have been prevented if folic acid fortification had been implemented in the 28 countries who were members of the European Union in 2019 was predicted was predicted using data on NTD prevalence from 35 EUROCAT congenital anomaly registries and literature searches for population serum folate levels and folic acid supplementation. Results: From 1998 to 2017 an estimated 95,213 NTD pregnancies occurred amongst 104 million births in the 28 countries in the EU, a prevalence of 0.92 per 1,000 births. The median serum folate level in Europe over this time period was estimated to be 14.1 μg/L. There is a lack of information about women taking folic acid supplements before becoming pregnant and during the first trimester of pregnancy, with one meta-analysis indicating that around 25% of women did so. An estimated 14,600 NTD pregnancies may have been prevented if the European countries had implemented fortification at the level adopted by the USA in 1998 and 25% of women took folic acid supplements. An estimated 19,500 NTD pregnancies would have been prevented if no women took folic acid supplements. Conclusions: This study suggests that failure to implement mandatory folic acid fortification in the 28 European countries has caused, and continues to cause, neural tube defects to occur in almost 1,000 pregnancies every year.

Exomphalos without other prenatally detected anomalies: Perinatal outcomes from 22 years of population-based data

OBJECTIVE

To ascertain the perinatal outcomes for an apparently isolated exomphalos detected by prenatal ultrasound.

METHOD

Our dataset captures cases from 614 321 births in the Wessex region of England and the Channel Isles on all cases of pre- or postnatally diagnosed exomphalos from 1994 to 2015. Ascertainment was >95%.

RESULTS

Three hundred and thirty five cases were reported to the register: 28 (8%) were not detected prenatally, 18 (6%) had already died in utero, 169 (55%) cases were found to have additional anomalies on first tertiary ultrasound scan and one case was lost to follow-up. Therefore 119 (39%) cases had an apparently isolated exomphalos. Of the 119 cases with only an exomphalos detected on first tertiary ultrasound scan, 25 (21%) had a chromosome abnormality. Of those with a normal or untested karyotype, 61% were confirmed to be an isolated anomaly after birth, 13% had an additional heart abnormality, 9% had Beckwith-Wiedemann syndrome and 11% had additional problems diagnosed postnatally.

CONCLUSION

Our large population-based dataset with an average of 1 year's postnatal follow-up suggests that more than one-third of apparently isolated prenatal cases of exomphalos will have an additional finding detected after birth. These data should help assist clinicians in their prenatal counseling.

Maternal risk factors for the VACTERL association: A EUROCAT case-control study

BACKGROUND

The VACTERL association (VACTERL) is the nonrandom occurrence of at least three of these congenital anomalies: vertebral, anal, cardiac, tracheoesophageal, renal, and limb anomalies. Despite suggestions for involvement of several genes and nongenetic risk factors from small studies, the etiology of VACTERL remains largely unknown.

OBJECTIVE

To identify maternal risk factors for VACTERL in offspring in a large European study.

METHODS

A case-control study was performed using data from 28 EUROCAT registries over the period 1997-2015 with case and control ascertainment through hospital records, birth and death certificates, questionnaires, and/or postmortem examinations. Cases were diagnosed with VACTERL, while controls had a genetic syndrome and/or chromosomal abnormality. Data collected included type of birth defect and maternal characteristics, such as age, use of assisted reproductive techniques (ART), and chronic illnesses. Multivariable logistic regression analyses were performed to estimate confounder adjusted odds ratios (aOR) with 95% confidence intervals (95% CI).

RESULTS

The study population consisted of 329 VACTERL cases and 49,724 controls with recognized syndromes or chromosomal abnormality. For couples who conceived through ART, we found an increased risk of VACTERL (aOR 2.3 [95% CI 1.3, 3.9]) in offspring. Pregestational diabetes (aOR 3.1 [95% CI 1.1, 8.6]) and chronic lower obstructive pulmonary diseases (aOR 3.9 [95% CI 2.2, 6.7]) also increased the risk of having a child with VACTERL. Twin pregnancies were not associated with VACTERL (aOR 0.6 [95% CI 0.3, 1.4]).

CONCLUSION

We identified several maternal risk factors for VACTERL in offspring befitting a multifactorial etiology.

Multilevel analyses of related public health indicators: The European Surveillance of Congenital Anomalies (EUROCAT) Public Health Indicators

BACKGROUND

Public health organisations use public health indicators to guide health policy. Joint analysis of multiple public health indicators can provide a more comprehensive understanding of what they are intended to evaluate.

OBJECTIVE

To analyse variaitons in the prevalence of congenital anomaly-related perinatal mortality attributable to termination of pregnancy for foetal anomaly (TOPFA) and prenatal diagnosis of congenital anomaly prevalence.

METHODS

We included 55 363 cases of congenital anomalies notified to 18 EUROCAT registers in 10 countries during 2008-12. Incidence rate ratios (IRR) representing the risk of congenital anomaly-related perinatal mortality according to TOPFA and prenatal diagnosis prevalence were estimated using multilevel Poisson regression with country as a random effect. Between-country variation in congenital anomaly-related perinatal mortality was measured using random effects and compared between the null and adjusted models to estimate the percentage of variation in congenital anomaly-related perinatal mortality accounted for by TOPFA and prenatal diagnosis.

RESULTS

The risk of congenital anomaly-related perinatal mortality decreased as TOPFA and prenatal diagnosis prevalence increased (IRR 0.79, 95% confidence interval [CI] 0.72, 0.86; and IRR 0.88, 95% CI 0.79, 0.97). Modelling TOPFA and prenatal diagnosis together, the association between congenital anomaly-related perinatal mortality and TOPFA prevalence became stronger (RR 0.70, 95% CI 0.61, 0.81). The prevalence of TOPFA and prenatal diagnosis accounted for 75.5% and 37.7% of the between-country variation in perinatal mortality, respectively.

CONCLUSION

We demonstrated an approach for analysing inter-linked public health indicators. In this example, as TOPFA and prenatal diagnosis of congenital anomaly prevalence decreased, the risk of congenital anomaly-related perinatal mortality increased. Much of the between-country variation in congenital anomaly-related perinatal mortality was accounted for by TOPFA, with a smaller proportion accounted for by prenatal diagnosis.

Risk of congenital anomalies near municipal waste incinerators in England and Scotland: Retrospective population-based cohort study

BACKGROUND

Few studies have investigated congenital anomalies in relation to municipal waste incinerators (MWIs) and results are inconclusive.

OBJECTIVES

To conduct a national investigation into the risk of congenital anomalies in babies born to mothers living within 10 km of an MWI associated with: i) modelled concentrations of PM₁₀ as a proxy for MWI emissions more generally and; ii) proximity of residential postcode to nearest MWI, in areas in England and Scotland that are covered by a congenital anomaly register.

METHODS

Retrospective population-based cohort study within 10 km of 10 MWIs in England and Scotland operating between 2003 and 2010. Exposure was proximity to MWI and log of daily mean modelled ground-level particulate matter ≤10 μm diameter (PM₁₀) concentrations.

RESULTS

Analysis included 219,486 births, stillbirths and terminations of pregnancy for fetal anomaly of which 5154 were cases of congenital anomalies. Fully adjusted odds ratio (OR) per doubling in PM₁₀ was: 1·00 (95% CI 0·98-1·02) for all congenital anomalies; 0·99 (0·97-1·01) for all congenital anomalies excluding chromosomal anomalies. For every 1 km closer to an MWI adjusted OR was: 1·02 (1·00-1·04) for all congenital anomalies combined; 1·02 (1·00-1·04) for all congenital anomalies excluding chromosomal anomalies; and, for specific anomaly groups, 1·04 (1·01-1·08) for congenital heart defect sand 1·07 (1·02-1·12) for genital anomalies.

DISCUSSION

We found no increased risk of congenital anomalies in relation to modelled PM₁₀ emissions, but there were small excess risks associated with congenital heart defects and genital anomalies in proximity to MWIs. These latter findings may well reflect incomplete control for confounding, but a possible causal effect cannot be excluded.

PAPSS2-related brachyolmia: Clinical and radiological phenotype in 18 new cases

Brachyolmia is a skeletal dysplasia characterized by short spine-short stature, platyspondyly, and minor long bone abnormalities. We describe 18 patients, from different ethnic backgrounds and ages ranging from infancy to 19 years, with the autosomal recessive form, associated with PAPSS2. The main clinical features include disproportionate short stature with short spine associated with variable symptoms of pain, stiffness, and spinal deformity. Eight patients presented prenatally with short femora, whereas later in childhood their short-spine phenotype emerged. We observed the same pattern of changing skeletal proportion in other patients. The radiological findings included platyspondyly, irregular end plates of the elongated vertebral bodies, narrow disc spaces and short over-faced pedicles. In the limbs, there was mild shortening of femoral necks and tibiae in some patients, whereas others had minor epiphyseal or metaphyseal changes. In all patients, exome and Sanger sequencing identified homozygous or compound heterozygous PAPSS2 variants, including c.809G>A, common to white European patients. Bi-parental inheritance was established where possible. Low serum DHEAS, but not overt androgen excess was identified. Our study indicates that autosomal recessive brachyolmia occurs across continents and may be under-recognized in infancy. This condition should be considered in the differential diagnosis of short femora presenting in the second trimester.

Epidemiology of achondroplasia: A population-based study in Europe

Achondroplasia is a rare genetic disorder resulting in short-limb skeletal dysplasia. We present the largest European population-based epidemiological study to date using data provided by the European Surveillance of Congenital Anomalies (EUROCAT) network. All cases of achondroplasia notified to 28 EUROCAT registries (1991-2015) were included in the study. Prevalence, birth outcomes, prenatal diagnosis, associated anomalies, and the impact of paternal and maternal age on de novo achondroplasia were presented. The study population consisted of 434 achondroplasia cases with a prevalence of 3.72 per 100,000 births (95%CIs: 3.14-4.39). There were 350 live births, 82 terminations of pregnancy after prenatal diagnosis, and two fetal deaths. The prenatal detection rate was significantly higher in recent years (71% in 2011-2015 vs. 36% in 1991-1995). Major associated congenital anomalies were present in 10% of cases. About 20% of cases were familial. After adjusting for maternal age, fathers >34 years had a significantly higher risk of having infants with de novo achondroplasia than younger fathers. Prevalence was stable over time, but regional differences were observed. All pregnancy outcomes were included in the prevalence estimate with 80.6% being live born. The study confirmed the increased risk for older fathers of having infants with de novo achondroplasia.

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 Ca_v2.2/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 Ca_v2.2 in normal human neurodevelopment.

Diagnosis and outcome in nonhydropic fetal pleural effusions

OBJECTIVE

To determine the outcome of all pregnancies with nonhydropic fetal pleural effusions in the Wessex region.

METHOD

Data were extracted from the Wessex congenital anomaly database for the years 1994-2015 inclusive.

RESULTS

Sixty-two fetuses and babies were identified giving a total prevalence of 1:9500. Eight fetuses had bilateral effusions with additional, nonhydrops anomalies, and 54 had isolated effusions. Of the isolated cases, 36 presented before 24-week gestation: 12 were unilateral and 24 bilateral. All of the unilateral effusions resolved before or soon after birth with no other diagnosis but of the bilateral cases, four (17%) had a trisomy and three (13%) a genetic or syndrome diagnosis. Eighteen isolated cases presented after 24-week gestation, six were unilateral of which one had trisomy 21 (17%), and three (50%) Noonan's or another lymphoedema syndrome. Twelve were bilateral: One had trisomy 21, one an unbalanced translocation (17%), three had Noonan's or another lymphoedema syndrome, and two an unspecified syndrome (42%) at birth.

CONCLUSION

These data suggest that a chromosomal microarray should be offered to all fetuses presenting with a pleural effusion in the absence of hydrops, and Noonan's syndrome testing should be considered for those that develop after 24 weeks.

AIM

To determine the outcome of all pregnancies with nonhydropic fetal pleural effusions in the Wessex region from 1994-2015.

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 severe developmental delays in four patients. More than 70% of the patients were able to perform the same activities of daily living when compared to peers.

CONCLUSIONS

Our data show that riboflavin treatment improves complex I activity in the majority of patient-derived fibroblasts tested. This effect was also reported for most of the treated patients and is mirrored in the survival data. In the patient group with disease-onset below 1 year of age, we observed a statistically-significant better survival for patients treated with riboflavin.

Epidemiology of septo-optic dysplasia with focus on prevalence and maternal age - A EUROCAT study

Septo-optic nerve dysplasia is a rare congenital anomaly with optic nerve hypoplasia, pituitary hormone deficiencies and midline developmental defects of the brain. The clinical findings are visual impairment, hypopituitarism and developmental delays. The aim of this study was to report prevalence, associated anomalies, maternal age and other epidemiological factors from a large European population based network of congenital anomaly registries (EUROCAT). Data from 29 full member registries for the years 2005-2014 were included, covering 6.4 million births. There were 99 cases with a diagnosis of septo-optic dysplasia. The prevalence of septo-optic dysplasia in Europe was calculated to lie between 1.9 and 2.5 per 100,000 births after adjusting for potential under-reporting in some registries. The prevalence was highest in babies of mothers aged 20-24 years of age and was significantly higher in UK registries compared with other EUROCAT registries (P = 0.021 in the multilevel model) and the additional risk for younger mothers was significantly greater in the UK compared to the rest of Europe (P = 0.027). The majority of septo-optic dysplasia cases were classified as an isolated cerebral anomaly (N = 76, 77%). Forty percent of diagnoses occurred in fetuses with a prenatal diagnosis. The anomaly may not be visible at birth, which is reflected in that 57% of the postnatal diagnoses occurred over 1 month after birth. This is the first population based study to describe the prevalence of septo-optic dysplasia in Europe. Septo-optic dysplasia shares epidemiological patterns with gastroschisis and this strengthens the hypothesis of vascular disruption being an aetiological factor for septo-optic dysplasia.

Trends in congenital anomalies in Europe from 1980 to 2012

BACKGROUND

Surveillance of congenital anomalies is important to identify potential teratogens.

METHODS

This study analysed the prevalence of 61 congenital anomaly subgroups (excluding chromosomal) in 25 population-based EUROCAT registries (1980-2012). Live births, fetal deaths and terminations of pregnancy for fetal anomaly were analysed with multilevel random-effects Poisson regression models.

RESULTS

Seventeen anomaly subgroups had statistically significant trends from 2003-2012; 12 increasing and 5 decreasing.

CONCLUSIONS

The annual increasing prevalence of severe congenital heart defects, single ventricle, atrioventricular septal defects and tetralogy of Fallot of 1.4% (95% CI: 0.7% to 2.0%), 4.6% (1.0% to 8.2%), 3.4% (1.3% to 5.5%) and 4.1% (2.4% to 5.7%) respectively may reflect increases in maternal obesity and diabetes (known risk factors). The increased prevalence of cystic adenomatous malformation of the lung [6.5% (3.5% to 9.4%)] and decreased prevalence of limb reduction defects [-2.8% (-4.2% to -1.5%)] are unexplained. For renal dysplasia and maternal infections, increasing trends may be explained by increased screening, and deceases in patent ductus arteriosus at term and increases in craniosynostosis, by improved follow up period after birth and improved diagnosis. For oesophageal atresia, duodenal atresia/stenosis and ano-rectal atresia/stenosis recent changes in prevalence appeared incidental when compared with larger long term fluctuations. For microcephaly and congenital hydronephrosis trends could not be interpreted due to discrepancies in diagnostic criteria. The trends for club foot and syndactyly disappeared once registries with disparate results were excluded. No decrease in neural tube defects was detected, despite efforts at prevention through folic acid supplementation.

Estimating Global Burden of Disease due to congenital anomaly: an analysis of European data

OBJECTIVE

To validate the estimates of Global Burden of Disease (GBD) due to congenital anomaly for Europe by comparing infant mortality data collected by EUROCAT registries with the WHO Mortality Database, and by assessing the significance of stillbirths and terminations of pregnancy for fetal anomaly (TOPFA) in the interpretation of infant mortality statistics.

DESIGN, SETTING AND OUTCOME MEASURES

EUROCAT is a network of congenital anomaly registries collecting data on live births, fetal deaths from 20 weeks' gestation and TOPFA. Data from 29 registries in 19 countries were analysed for 2005-2009, and infant mortality (deaths of live births at age <1 year) compared with the WHO Mortality Database. Eight EUROCAT countries were excluded from further analysis on the basis that this comparison showed poor ascertainment of survival status.

RESULTS

According to WHO, 17%-42% of infant mortality was attributed to congenital anomaly. In 11 EUROCAT countries, average infant mortality with congenital anomaly was 1.1 per 1000 births, with higher rates where TOPFA is illegal (Malta 3.0, Ireland 2.1). The rate of stillbirths with congenital anomaly was 0.6 per 1000. The average TOPFA prevalence was 4.6 per 1000, nearly three times more prevalent than stillbirths and infant deaths combined. TOPFA also impacted on the prevalence of postneonatal survivors with non-lethal congenital anomaly.

CONCLUSIONS

By excluding TOPFA and stillbirths from GBD years of life lost (YLL) estimates, GBD underestimates the burden of disease due to congenital anomaly, and thus declining YLL over time may obscure lack of progress in primary, secondary and tertiary prevention.

Use of hierarchical models to analyze European trends in congenital anomaly prevalence

BACKGROUND

Surveillance of congenital anomalies is important to identify potential teratogens. Despite known associations between different anomalies, current surveillance methods examine trends within each subgroup separately. We aimed to evaluate whether hierarchical statistical methods that combine information from several subgroups simultaneously would enhance current surveillance methods using data collected by EUROCAT, a European network of population-based congenital anomaly registries.

METHODS

Ten-year trends (2003 to 2012) in 18 EUROCAT registries over 11 countries were analyzed for the following groups of anomalies: neural tube defects, congenital heart defects, digestive system, and chromosomal anomalies. Hierarchical Poisson regression models that combined related subgroups together according to EUROCAT's hierarchy of subgroup coding were applied. Results from hierarchical models were compared with those from Poisson models that consider each congenital anomaly separately.

RESULTS

Hierarchical models gave similar results as those obtained when considering each anomaly subgroup in a separate analysis. Hierarchical models that included only around three subgroups showed poor convergence and were generally found to be over-parameterized. Larger sets of anomaly subgroups were found to be too heterogeneous to group together in this way.

CONCLUSION

There were no substantial differences between independent analyses of each subgroup and hierarchical models when using the EUROCAT anomaly subgroups. Considering each anomaly separately, therefore, remains an appropriate method for the detection of potential changes in prevalence by surveillance systems. Hierarchical models do, however, remain an interesting alternative method of analysis when considering the risks of specific exposures in relation to the prevalence of congenital anomalies, which could be investigated in other studies. Birth Defects Research (Part A) 106:480-10, 2016. © 2016 Wiley Periodicals, Inc.

Prevalence of microcephaly in Europe: population based study

OBJECTIVES

 To provide contemporary estimates of the prevalence of microcephaly in Europe, determine if the diagnosis of microcephaly is consistent across Europe, and evaluate whether changes in prevalence would be detected using the current European surveillance performed by EUROCAT (the European Surveillance of Congenital Anomalies).

DESIGN

 Questionnaire and population based observational study.

SETTING

 24 EUROCAT registries covering 570 000 births annually in 15 countries.

PARTICIPANTS

 Cases of microcephaly not associated with a genetic condition among live births, fetal deaths from 20 weeks' gestation, and terminations of pregnancy for fetal anomaly at any gestation.

MAIN OUTCOME MEASURES

 Prevalence of microcephaly (1 Jan 2003-31 Dec 2012) analysed with random effects Poisson regression models to account for heterogeneity across registries.

RESULTS

 16 registries responded to the questionnaire, of which 44% (7/16) used the EUROCAT definition of microcephaly (a reduction in the size of the brain with a skull circumference more than 3 SD below the mean for sex, age, and ethnic origin), 19% (3/16) used a 2 SD cut off, 31% (5/16) were reliant on the criteria used by individual clinicians, and one changed criteria between 2003 and 2012. Prevalence of microcephaly in Europe was 1.53 (95% confidence interval 1.16 to 1.96) per 10 000 births, with registries varying from 0.4 (0.2 to 0.7) to 4.3 (3.6 to 5.0) per 10 000 (χ(2)=338, df=23, I(2)=93%). Registries with a 3 SD cut off reported a prevalence of 1.74 per 10 000 (0.86 to 2.93) compared with those with the less stringent 2 SD cut off of 1.21 per 10 000 (0.21 to 2.93). The prevalence of microcephaly would need to increase in one year by over 35% in Europe or by over 300% in a single registry to reach statistical significance (P<0.01).

CONCLUSIONS

 EUROCAT could detect increases in the prevalence of microcephaly from the Zika virus of a similar magnitude to those observed in Brazil. Because of the rarity of microcephaly and discrepant diagnostic criteria, however, the smaller increases expected in Europe would probably not be detected. Clear diagnostic criteria for microcephaly must be adopted across Europe.

Prevention of neural tube defects in the UK: a missed opportunity

OBJECTIVE

In 1991, the Medical Research Council (MRC) Vitamin Study demonstrated that folic acid taken before pregnancy and in early pregnancy reduced the risk of a neural tube defect (NTD). We aimed to estimate the number of NTD pregnancies that would have been prevented if flour had been fortified with folic acid in the UK from 1998 as it had been in the USA.

DESIGN

Estimates of NTD prevalence, the preventive effect of folic acid and the proportion of women taking folic acid supplements before pregnancy were used to predict the number of NTD pregnancies that would have been prevented if folic acid fortification had been implemented.

SETTING

Eight congenital anomaly registers in England and Wales.

MAIN OUTCOME MEASURES

The prevalence of pregnancies with an NTD in the UK and the number of these pregnancies that would have been prevented if folic acid fortification had been implemented.

RESULTS

From 1991 to 2012, the prevalence of NTD pregnancies was 1.28 (95% CI 1.24 to 1.31) per 1000 total births (19% live births, 81% terminations and 0.5% stillbirths and fetal deaths ≥20 weeks' gestation). If the USA levels of folic acid fortification from 1998 onwards had been adopted in the UK, an estimated 2014 fewer NTD pregnancies would have occurred.

CONCLUSIONS

Failure to implement folic acid fortification in the UK has caused, and continues to cause, avoidable terminations of pregnancy, stillbirths, neonatal deaths and permanent serious disability in surviving children.

Lamotrigine use in pregnancy and risk of orofacial cleft and other congenital anomalies

OBJECTIVE

To test previous signals of a risk of orofacial cleft (OC) and clubfoot with exposure to the antiepileptic lamotrigine, and to investigate risk of other congenital anomalies (CA).

METHODS

This was a population-based case-malformed control study based on 21 EUROCAT CA registries covering 10.1 million births (1995-2011), including births to 2005 in which the clubfoot signal was generated and a subsequent independent study population of 6.3 million births. A total of 226,806 babies with CA included livebirths, stillbirths, and terminations of pregnancy following prenatal diagnosis. First-trimester lamotrigine monotherapy exposure in OC cases and clubfoot cases was compared to other nonchromosomal CA (controls). Odds ratios (OR) were adjusted for registry. An exploratory analysis compared the proportion of each standard EUROCAT CA subgroup among all babies with nonchromosomal CA exposed to lamotrigine monotherapy with non-AED exposed pregnancies.

RESULTS

There were 147 lamotrigine monotherapy-exposed babies with nonchromosomal CA. For all OC, ORadj was 1.31 (95% confidence interval [CI] 0.73-2.33), isolated OC 1.45 (95% CI 0.80-2.63), isolated cleft palate 1.69 (95% CI 0.69-4.15). Overall ORadj for clubfoot was 1.83 (95% CI 1.01-3.31) and 1.43 (95% CI 0.66-3.08) in the independent study population. No other specific CA were significantly associated with lamotrigine monotherapy.

CONCLUSIONS

The risk of OC was not significantly raised and we estimate the excess risk of OC to be less than 1 in every 550 exposed babies. We have not found strong independent evidence of a risk of clubfoot subsequent to our original signal. Our study cannot assess the general malformation risk among lamotrigine-exposed pregnancies.

What results to disclose, when, and who decides? Healthcare professionals' views on prenatal chromosomal microarray analysis

Objectives

This study explored the views of healthcare professionals (HCPs) in the UK about what information should be disclosed, when; and whether women/parents should be given a choice as to what they wish to know.

Methods

Q‐methodology was used to assess the views of 40 HCPs (genetic HCPs, fetal medicine experts, lab‐scientists).

Results

Most participants agreed that variants of unknown clinical significance should not be disclosed. Participants were divided between those who considered variants of uncertain clinical significance helpful for parents and clinicians, and those who considered them harmful. Although recognising the potential disadvantages of disclosing risks for adult‐onset conditions, participants thought it would be difficult to withhold such information once identified. Participants largely supported some parental involvement in determining which results should be returned. Most participants believed that information obtained via CMA testing in pregnancy should either be disclosed during pregnancy, or not at all.

Conclusion

HCPs taking part in the study largely believed that variants that will inform the management of the pregnancy, or are relevant to other family members, should be reported. Recent UK guidelines, published after this research was completed, reflect these opinions. © 2016 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.

What's already known about this topic?

Empirical data on healthcare professionals' (HCPs) and parents' experience with prenatal CMA are scarce.

Published data mainly focused on issues around uncertain results obtained via CMA, and on genetic health professionals.

The two main difficulties expressed by genetic counsellors associated with testing were interpreting uncertain results, and termination of pregnancies based on uncertain results

What does this study add?

It is the first study examining attitudes of a wide range of professionals involved in CMA testing: laboratory professionals, fetal medicine experts, and genetic health professionals.

We describe what types of results professionals think should or should not be disclosed and with whom they consider the onus for such decision making should lie.

These views are reflected in the recent UK guidelines about CMA testing.

Long term trends in prevalence of neural tube defects in Europe: population based study

STUDY QUESTION

What are the long term trends in the total (live births, fetal deaths, and terminations of pregnancy for fetal anomaly) and live birth prevalence of neural tube defects (NTD) in Europe, where many countries have issued recommendations for folic acid supplementation but a policy for mandatory folic acid fortification of food does not exist?

METHODS

This was a population based, observational study using data on 11,353 cases of NTD not associated with chromosomal anomalies, including 4162 cases of anencephaly and 5776 cases of spina bifida from 28 EUROCAT (European Surveillance of Congenital Anomalies) registries covering approximately 12.5 million births in 19 countries between 1991 and 2011. The main outcome measures were total and live birth prevalence of NTD, as well as anencephaly and spina bifida, with time trends analysed using random effects Poisson regression models to account for heterogeneities across registries and splines to model non-linear time trends.

SUMMARY ANSWER AND LIMITATIONS

Overall, the pooled total prevalence of NTD during the study period was 9.1 per 10,000 births. Prevalence of NTD fluctuated slightly but without an obvious downward trend, with the final estimate of the pooled total prevalence of NTD in 2011 similar to that in 1991. Estimates from Poisson models that took registry heterogeneities into account showed an annual increase of 4% (prevalence ratio 1.04, 95% confidence interval 1.01 to 1.07) in 1995-99 and a decrease of 3% per year in 1999-2003 (0.97, 0.95 to 0.99), with stable rates thereafter. The trend patterns for anencephaly and spina bifida were similar, but neither anomaly decreased substantially over time. The live birth prevalence of NTD generally decreased, especially for anencephaly. Registration problems or other data artefacts cannot be excluded as a partial explanation of the observed trends (or lack thereof) in the prevalence of NTD.

WHAT THIS STUDY ADDS

In the absence of mandatory fortification, the prevalence of NTD has not decreased in Europe despite longstanding recommendations aimed at promoting peri-conceptional folic acid supplementation and existence of voluntary folic acid fortification.

FUNDING, COMPETING INTERESTS, DATA SHARING

The study was funded by the European Public Health Commission, EUROCAT Joint Action 2011-2013. HD and ML received support from the European Commission DG Sanco during the conduct of this study. No additional data available.

Large-scale discovery of novel genetic causes of developmental disorders

Despite three decades of successful, predominantly phenotype-driven discovery of the genetic causes of monogenic disorders, up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis. Particularly challenging are those disorders rare enough to have eluded recognition as a discrete clinical entity, those with highly variable clinical manifestations, and those that are difficult to distinguish from other, very similar, disorders. Here we demonstrate the power of using an unbiased genotype-driven approach to identify subsets of patients with similar disorders. By studying 1,133 children with severe, undiagnosed developmental disorders, and their parents, using a combination of exome sequencing and array-based detection of chromosomal rearrangements, we discovered 12 novel genes associated with developmental disorders. These newly implicated genes increase by 10% (from 28% to 31%) the proportion of children that could be diagnosed. Clustering of missense mutations in six of these newly implicated genes suggests that normal development is being perturbed by an activating or dominant-negative mechanism. Our findings demonstrate the value of adopting a comprehensive strategy, both genome-wide and nationwide, to elucidate the underlying causes of rare genetic disorders.