Congenital heart disease and Down syndrome: various aspects of a confirmed association

Critical issue in the identification of Down syndrome and its problems in Central Java, Indonesia: The fact of needing health care and better management

We conducted a cross-sectional study to describe the health care problems of children with Down syndrome in Central Java, Indonesia. A total of 162 children (81 boys, 81 girls) with Down syndrome were included. Congenital heart defects and hypothyroidism were found in about 50%, followed by vision and hearing problems in 27.7% and 17.3%, respectively. Almost half of cases were diagnosed after the first month of age. Advanced maternal age was identified in more than 50%, and less than 10% was based on karyotype analysis. This study describes the essential issues such as critical co-morbidities, delayed diagnosis, advanced maternal age, and lack of (accessibility to) genetic testing facilities; thus, better health care and management is needed.

Analysis of Down syndrome newborn outcomes in three neonatal intensive care units in Rio de Janeiro, Brazil

OBJECTIVE

The aim of this study was to analyze the outcomes of newborns with Down syndrome admitted to three neonatal intensive care units in the city of Rio de Janeiro, Brazil.

METHODS

A retrospective cohort study was conducted by analyzing the medical records between 2014 and 2018 of newborns with Down syndrome admitted to three neonatal intensive care units. The following variables were analyzed: maternal and perinatal data, neonatal malformations, neonatal intensive care unit intercurrences, and outcomes.

RESULTS

A total of 119 newborns with Down syndrome were recruited, and 112 were selected for analysis. The most common maternal age group was >35 years (72.07%), the most common type of delivery was cesarean section (83.93%), and the majority of cases were male (53.57%). The most common reasons for neonatal intensive care unit hospitalization were congenital heart disease (57.66%) and prematurity (23.21%). The most common form of feeding was a combination of human milk and formula (83.93%). The second most common malformation was duodenal atresia (9.82%). The most common complications during neonatal intensive care unit hospitalization were transient tachypnea of the newborn (63.39%), hypoglycemia (18.75%), pulmonary hypertension (7.14%), and sepsis (7.14%). The mean length of stay in the neonatal intensive care unit was 27 days. The most common outcome was discharge (82.14%). Furthermore, 12.50% of newborns were transferred to an external neonatal intensive care unit, and 6% died.

CONCLUSION

Newborns with Down syndrome are more likely to be admitted to the neonatal intensive care unit, and the length of hospital stay is longer due to complications related to congenital malformations common to this syndrome and prematurity.

Nationwide hospitalizations of patients with down syndrome and congenital heart disease over a 15-year period

Down syndrome is one of the most common genetic diseases, generally associated with an increased probability of congenital heart diseases. This increased risk contributes to escalated levels of morbidity and mortality. In this study, we sought to analyze nationwide data of pediatric and adult patients with Down syndrome and congenital heart disease over a 15-year period. Data obtained from the hospital discharge form between 2001 and 2016 of patients diagnosed with Down syndrome in Italy and at least one congenital heart disease were included. Information on 12362 admissions of 6527 patients were included. Age at first admission was 6.2 ± 12.8 years and was a predictor of mortality (HR = 1.51, 95% CI 1.13-2.03, p = 0.006). 3923 (60.1%) patients underwent only one admission, while 2604 (39.9%) underwent multiple (> 1) admissions. There were 5846 (47.3%) admissions for cardiac related symptoms. Multiple admissions (SHR: 3.13; 95% CI: 2.99, 3.27; P < 0.01) and cardiac admissions (SHR: 2.00; 95% CI: 1.92, 2.09; P < 0.01) were associated with an increased risk of additional potential readmissions. There was an increased risk of mortality for patients who had cardiac admissions (HR = 1.45, 95% CI: 1.08-1.94, p = 0.012), and for those who underwent at least 1 cardiac surgical procedure (HR = 1.51, 95% CI 1.13-2.03, p = 0.006).

CONCLUSIONS

A younger age at first admission is a predictor for mortality in patients with Down syndrome and congenital heart disease. If patients undergo more than one admission, the risk of further readmissions increases. There is a pivotal role for heart disease in influencing the hospitalization rate and subsequent mortality.

WHAT IS KNOWN

• Down syndrome individuals often face an increased risk of congenital heart diseases. • Congenital heart diseases contribute significantly to morbidity and mortality in Down syndrome patients.

WHAT IS NEW

• This study analyzes nationwide data covering a 15-year period of pediatric and adult patients in Italy with Down syndrome and congenital heart disease. • It identifies a younger age at first admission as a predictor for mortality in these patients, emphasizing the criticality of early intervention. • Demonstrates a correlation between multiple admissions, particularly those related to cardiac issues, and an increased risk of further readmissions, providing insights into the ongoing healthcare needs of these individuals.

The role of Down syndrome cell adhesion molecule in Down syndrome

Down syndrome (DS) is caused by the presence of an extra copy of the entire or a portion of human chromosome 21 (HSA21). This genomic alteration leads to elevated expression of numerous HSA21 genes, resulting in a variety of health issues in individuals with DS. Among the genes located in the DS "critical region" of HSA21, Down syndrome cell adhesion molecule (DSCAM) plays an important role in neuronal development. There is a growing body of evidence underscoring DSCAM's involvement in various DS-related disorders. This review aims to provide a concise overview of the established functions of DSCAM, with a particular focus on its implications in DS. We delve into the roles that DSCAM plays in DS-associated diseases. In the concluding section of this review, we explore prospective avenues for future research to further unravel DSCAM's role in DS and opportunities for therapeutic treatments.

Gender and its association with cardiac defects in down syndrome population at Children Hospital & Institute of Child Health, Lahore, Pakistan

Objective

The objective of this study was to determine the frequency of different congenital cardiac defects co-existing in karyotypically proved Down syndrome population. It also highlighted the association between gender and pattern of congenital cardiac defects and gender as a risk factor.

Methods

A cross sectional comparative study was done in the Department of Genetics, Children Hospital Lahore in the year 2017. A total of 160 patients were subjected to karyotypic analysis through blood test for determining the type of Down Syndrome and Echocardiography of all established cases was performed for determining presence and types of congenital cardiac defects. Results were evaluated in terms of establishing co-existence of various cardiac phenotypes in Down Syndrome cases.

Results

In karyotypically proven 160 cases of Down syndrome, 58.1% of Down Syndrome cases and 88.2% of Down Syndrome with Congenital Cardiac Defects presented in infancy. The odds ratio (OR) suggested that females are 1.72 times more likely to experience a cardiac effect compared to males. Female gender was potentially associated (p-value 0.07) with occurrence of Patent Ductus Arteriosus (47.8%), whereas VSD (Ventricular Septal Defects) was most prevalent (41.1%) in males. Patent Ductus Arteriosus + Atrial Septal Defects (44.4%) was the commonest cardiac defect in female cases. The combined data for pattern of cardiac anomalies showed no significant association with gender, as indicated by a p-value of 0.990.

Conclusion

The study concluded that most of Down syndrome cases and Down syndrome with congenital cardiac defects present to the hospital in infancy. Female cases are more prone to develop cardiac defects as compared to males. The manifestation of PDA (Patent Ductus Arteriosus) was significantly associated as an isolated anomaly in females and VSD (Ventricular Septal Defects) as isolated anomaly in males. Patent Ductus Arteriosus tend to co-exist most with ASD (Atrial Septal Defects) in female cases. Gender was not established as a risk factor for affecting the pattern of cardiac defects.

Serological investigation of vaccine-induced antibodies for measles, rubella, and yellow fever viruses in children vertically exposed to Zika virus or with down syndrome

Background

Vaccination schedules, as well as their effectiveness and contraindications, need to be evaluated regularly, especially in specific situations. Congenital Zika Syndrome (CZS) is a severe condition that results in extensive functional and neurological impairment of fetuses and newborns due to Zika virus tropism for fetal neural progenitor cells. Down Syndrome (DS) is the leading genetic cause of intellectual disability. The immune impairment in DS has already been described, but little is known about the immune response of CZS children. Thus, CZS and DS are specific conditions that can be considered for a reassessment of the available immunizations. Here, we carried out serological analyses of attenuated vaccines-induced antibodies for measles, rubella, and yellow fever viruses in children aged 2-7, grouped into asymptomatic controls, DS children, and CZS children.

Methods

Plasma samples were taken, and vaccination records were compiled during clinical follow-up. Enzymatic immunoassays for quantifying anti-measles and anti-rubella IgG were performed to assess the response to the Measles, Mumps, and Rubella (MMR) vaccine. Plaque Reduction Neutralization Test (PRNT) was performed to investigate neutralizing antibodies in response to the Brazilian vaccine strain of yellow fever (YF-17DD).

Results

We highlight similar levels of anti-measles IgG and neutralizing antibodies for YF-17DD among CZS, DS, and asymptomatic children, although low positivity of measles data was seen in the three groups. In DS children, the 2-4-year-old group had an increased level of anti-measles IgG compared to the older group of children aged five to seven years. Lower anti-rubella IgG levels were observed in CZS and DS children compared to asymptomatic children. For anti-rubella IgG, the good performance of vaccination in asymptomatic children is due to younger ones rather than older ones.

Conclusions

There were no reports of adverse events after the use of the MMR and YF-17DD indicating that CZS and DS could continue to receive these vaccines, but our data draws attention to the necessity of monitoring the vaccination response in CZS and DS children over time and the possible need to adhere to national measles vaccination campaigns. Scientific research needs to continue to help develop appropriate CZS and DS health guidelines.

Congenital Heart Defects and Outcome in a Large Cohort of Down Syndrome: A Single-Center Experience from Turkey

OBJECTIVE

Congenital heart defects occur in approximately 50% of children with Down syndrome and they contribute considerably to morbidity and mortality. The aim of this study is to investigate the prevalence, classification, and survival of congenital heart defects in Down syndrome.

MATERIALS AND METHODS

About 1731 Down syndrome patients who underwent echocardiography between 1986 and 2022 were evaluated. The median follow-up duration was 8.7 years (range 1-35.8 years). Congenital heart defect was grouped as cyanotic and acyanotic.

RESULTS

Among the 1731 patients, 52.1% had congenital heart defects. Congenital heart defect was significantly more common in females than males. The most common cardiac defect was ventricular septal defect (35%), followed by atrial septal defect (31.8%), atrioventricular septal defect (23.4%), tetralogy of Fallot (5%), and patent ductus arteriosus (3.6%). In the follow-up, 43.2% of atrial septal defect, 17.8% of ventricular septal defect, and a total of 20% of congenital heart defects were closed spontaneously. About 34.4% of congenital heart defect was corrected by cardiac surgery/intervention. Five-year survival rate was 97.4% in patients without congenital heart defects, whereas it was 95.6% in mild congenital heart defects and 86.1% in moderate to severe congenital heart defects. There was no relationship between consanguinity, parental age, maternal disease, folic acid supplementation before/during pregnancy, gestational age, birth weight, and congenital heart defects. Neuromotor development was similar in patients with and without congenital heart defects.

CONCLUSION

We demonstrated that almost half of the patients had congenital heart defects; ventricular septal defect was the most common congenital heart defect type. This study is valuable in terms of the largest single-center study describing the classification, prognostic factors, and survival of Down syndrome patients with congenital heart defect from Turkey.

Dysphagia severity is associated with worse sleep-disordered breathing in infants with Down syndrome

STUDY OBJECTIVES

Hypotonia, commonly seen in infants with Down syndrome (I-DS), can contribute to masticatory and oropharyngeal muscle weakness, increasing the risk for dysphagia and sleep-disordered breathing. Data describing the occurrence of dysphagia and sleep-disordered breathing in I-DS are limited. This study aims to determine the frequency and severity of dysphagia and its relationship to polysomnogram parameters in I-DS.

METHODS

We included I-DS who underwent polysomnography at a single academic center over a 6-year period. Data collected included sex, age, presence of dysphagia (low suspicion of dysphagia vs dysphagia vs feeding tube), and polysomnographic data. Dysphagia was determined by a video fluoroscopic swallow study in the presence of clinical suspicion.

RESULTS

A total of 40 I-DS were identified (mean age 6.6 months ± 3; male 65%). There were 11, 13, and 16 I-DS with low suspicion of dysphagia, dysphagia, and feeding tube, respectively. Obstructive sleep apnea was more severe in I-DS in the feeding tube group when compared with the group with a low suspicion of dysphagia and (apnea-hypopnea index mean [standard error] = 49.3 [7.6] vs 19.2 [9.2] events/h; P = .016). Dysphagia severity was positively correlated with a higher obstructive apnea-hypopnea index (r = .43, P = .006).

CONCLUSIONS

There is a high incidence of dysphagia and sleep-disordered breathing in I-DS. Dysphagia severity correlated with obstructive apnea-hypopnea index severity. Our results suggest that I-DS need early evaluation of both sleep-disordered breathing and dysphagia.

CITATION

Cho Y, Kwon Y, DelRosso L, Sobremonte-King M. Dysphagia severity is associated with worse sleep-disordered breathing in infants with Down syndrome. J Clin Sleep Med. 2023;19(5):883-887.

Endocrine Disorders in a Newborn with Heterozygous Galactosemia, Down Syndrome and Complex Cardiac Malformation: Case Report

Down syndrome is the most common chromosomal abnormality diagnosed in newborn babies. Infants with Down syndrome have characteristic dysmorphic features and can have neuropsychiatric disorders, cardiovascular diseases, gastrointestinal abnormalities, eye problems, hearing loss, endocrine and hematologic disorders, and many other health issues. We present the case of a newborn with Down syndrome. The infant was a female, born at term through c-section. She was diagnosed before birth with a complex congenital malformation. In the first few days of life, the newborn was stable. In her 10th day of life, she started to show respiratory distress, persistent respiratory acidosis, and persistent severe hyponatremia, and required intubation and mechanical ventilation. Due to her rapid deterioration our team decided to do a screening for metabolic disorders. The screening was positive for heterozygous Duarte variant galactosemia. Further testing on possible metabolic and endocrinologic issues that can be associated with Down syndrome was performed, leading to hypoaldosteronism and hypothyroidism diagnoses. The case was challenging for our team because the infant also had multiple metabolic and hormonal deficiencies. Newborns with Down syndrome often require a multidisciplinary team, as besides congenital cardiac malformations they can have metabolic and hormonal deficiencies that can negatively impact their short- and long-term prognosis.

The burden of sleep disordered breathing in infants with Down syndrome referred to tertiary sleep center

INTRODUCTION

Children with Down Syndrome (DS) are at high risk of sleep disordered breathing (SDB). We aimed to examine the burden of SDB in infants with DS referred to tertiary sleep center.

METHODS

Infants (≤12 months old) with DS who underwent consecutive polysomnography (PSG) at a single academic sleep center over a 6-year period were included. obstructive sleep apnea (OSA) (obstructive apnea hypopnea index [oAHI]>1/hr), central sleep apnea (central apnea index > 5/h) and the presence of hypoventilation (% time spent with CO2  > 50 mmHg either by end-tidal or transcutaneous> 25% of total sleep time) and hypoxemia (time spent with O2 saturation <88% >5 min) were ascertained.

RESULTS

A total of 40 infants were included (Mean age 6.6 months, male 66%). PSGs consisted of diagnostic (n = 13) and split night (n = 27, 68%) studies. All met criteria for OSA with mean oAHI 34.6/h (32.3). Central sleep apnea was present in 11 (27.5%) of infants. A total of 11 (27.5%) had hypoxemia. Hypoventilation was present in 10 (25%) infants.

CONCLUSION

This study highlights the high prevalence of SDB in infants with DS referred to a sleep center, and supports early PSG assessment in this patient population.

DNMT3B rs2424913 as a Risk Factor for Congenital Heart Defects in Down Syndrome

Impairments of the genes that encode enzymes that are involved in one-carbon metabolism because of the presence of gene polymorphisms can affect the methylation pattern. The altered methylation profiles of the genes involved in cardiogenesis may result in congenital heart defects (CHDs). The aim of this study was to investigate the association between the MTHFR rs1801133, MTHFR rs1801131, MTRR rs1801394, DNMT1 rs2228611, DNMT3A rs1550117, DNMT3B rs1569686, and DNMT3B rs2424913 gene polymorphisms and congenital heart defects in Down syndrome (DS) individuals. The study was conducted on 350 participants, including 134 DS individuals with CHDs (DSCHD+), 124 DS individuals without CHDs (DSCHD−), and 92 individuals with non-syndromic CHD. The genotyping was performed using the PCR–RFLP method. A statistically significant higher frequency of the DNMT3B rs2424913 TT in the DSCHD+ individuals was observed. The DNMT3B rs2424913 TT genotype, as well as the T allele, had significantly higher frequencies in the individuals with DS and atrial septal defects (ASDs) in comparison with the individuals with DS and other CHDs. Furthermore, our results indicate a statistically significant effect of the DNMT3B rs1569686 TT genotype in individuals with non-syndromic CHDs. The results of the study suggest that the DNMT3B rs2424913 TT genotypes may be a possible predisposing factor for CHDs in DS individuals, and especially those with ASDs.

Pulmonary Hypertension in Children with Down Syndrome: Results from the Pediatric Pulmonary Hypertension Network Registry

OBJECTIVE

To characterize distinct comorbidities, outcomes, and treatment patterns in children with Down syndrome and pulmonary hypertension in a large, multicenter pediatric pulmonary hypertension registry.

STUDY DESIGN

We analyzed data from the Pediatric Pulmonary Hypertension Network (PPHNet) Registry, comparing demographic and clinical characteristics of children with Down syndrome and children without Down syndrome. We examined factors associated with pulmonary hypertension resolution and a composite outcome of pulmonary hypertension severity in the cohort with Down syndrome.

RESULTS

Of 1475 pediatric patients with pulmonary hypertension, 158 (11%) had Down syndrome. The median age at diagnosis of pulmonary hypertension in patients with Down syndrome was 0.49 year (IQR, 0.21-1.77 years), similar to that in patients without Down syndrome. There was no difference in rates of cardiac catheterization and prescribed pulmonary hypertension medications in children with Down syndrome and those without Down syndrome. Comorbidities in Down syndrome included congenital heart disease (95%; repaired in 68%), sleep apnea (56%), prematurity (49%), recurrent respiratory exacerbations (35%), gastroesophageal reflux (38%), and aspiration (31%). Pulmonary hypertension resolved in 43% after 3 years, associated with a diagnosis of pulmonary hypertension at age <6 months (54% vs 29%; P = .002) and a pretricuspid shunt (65% vs 38%; P = .02). Five-year transplantation-free survival was 88% (95% CI, 80%-97%). Tracheostomy (hazard ratio [HR], 3.29; 95% CI, 1.61-6.69) and reflux medication use (HR, 2.08; 95% CI, 1.11-3.90) were independently associated with a composite outcome of severe pulmonary hypertension.

CONCLUSIONS

Despite high rates of cardiac and respiratory comorbidities that influence the severity of pulmonary hypertension, children with Down syndrome-associated pulmonary hypertension generally have a survival rate similar to that of children with non-Down syndrome-associated pulmonary hypertension. Resolution of pulmonary hypertension is common but reduced in children with complicated respiratory comorbidities.

Eisenmenger Syndrome Among Children with Unrepaired Congenital Heart Defects in Yunnan, China

Eisenmenger syndrome is a life-threatening complication of congenital heart defects (CHD). Since Eisenmenger syndrome among children of repaired CHD is rare, very few studies have had the necessary data to investigate its distribution in children. The current study used data collected in rural China to investigate the prevalence of Eisenmenger syndrome in children with unrepaired CHD. Data were from the 2006 to 2016 patient medical records of China California Heart Watch, which is a traveling cardiology clinic in Yunnan Province, China. Patients were included if they (1) aged 18 or below, (2) had CHD(s), and (3) the defect was not repaired by the time of the clinic visit. The prevalence of Eisenmenger syndrome was calculated in each age and defect group. Using logistic regression models, we tested whether oxygen saturation, Down syndrome, sex, and age were significantly associated with Eisenmenger syndrome. Of the 1301 study participants, ventricular septum defect (VSD), atrial septal defect (ASD), and patent ductus arteriosus (PDA) were the most common CHD. About one-sixth of the patients had pulmonary hypertension and 1.5% had Eisenmenger syndrome. The percentages of Eisenmenger syndrome were 1.8% in VSD patients, 0 in ASD patients, and 0.9% in PDA patients. Patients in the age group between 15 and 18 years had the highest percentages of Eisenmenger syndrome (11.5%). Age and presence of Down syndrome were significantly associated with the presence of Eisenmenger syndrome. Our finding highlights the importance of early detection and correction of CHD.

Physical Activity and Physical and Mental Health in Middle-Aged Adults with Down Syndrome

Background

Adults with Down syndrome have an increased risk of aging-related physical and mental health conditions and experience them at an earlier age than the general population. There is a need to investigate modifiable lifestyle factors that may reduce risk for these conditions.

Method

The present study investigated the associations between physical activity (i.e., sedentary behavior and moderate-to-vigorous activity) assessed via accelerometer across 7 days and caregiver-reported physical and mental health of 66 non-demented middle-aged adults with Down Syndrome aged 25-55 years (52% female).

Results

Regression analyses indicated that more time spent in moderate intensity physical activity was associated with less risk of sleep apnea (b = -.031 p = .004) and endocrine/metabolic conditions (b = -.046 p = .009), and lower total number of physical health conditions (b = -.110 p =.016) and anxiety disorders (b = -.021 p =.049) after controlling for relevant sociodemographics. After also adjusting for BMI, the association between time spent in moderate intensity physical activity and sleep apnea (b=-.035, p = .002), endocrine/metabolic conditions (b=-.033, p = .045) and total physical health (b=-.091, p =.026) remained significant Unexpectedly, time spent in sedentary behavior was negatively associated with musculoskeletal conditions (b=-.017, p = .044).

Conclusion

Findings indicate important associations between physical activity in everyday life and the physical and mental health of adults with Down syndrome. Social policies and interventions aimed at reducing time spent sitting around (i.e., sedentary behavior) and encouraging moderate-to-vigorous activity may be a low-burden and low-cost mechanism for fostering healthy physical and mental aging in the Down syndrome population.

The Value of Fetal Heart Evaluation in Fetuses with Rare Congenital Lymphangiomas: A Cohort Study from a Single Tertiary Center across Two Decades (Years 1999-2020)

Lymphangiomas are uncommon, benign (from a histopathology viewpoint) malformations of the lymphatic system with thin-walled vessels; however, these tumors may be dangerous for fetal or neonatal life. They are observed in 1:6000 newborns at birth and in 1:750 spontaneous abortions. We aimed to investigate the role of fetal echocardiography in the prognosis of lymphangioma. Selected data of 19,836 pregnant women studied between 1999 and 2020 were retrospectively analyzed. In total, 32 cases of lymphangioma meeting the following criteria were further analyzed: (1) ultrasound availability from the 1st trimester of pregnancy and (2) nuchal translucency ≤ 2.5 mm. Echocardiographic findings, karyotype, size, and location of the possible lesion were juxtaposed with the clinical follow-up. The statistical analysis was performed using Statistica 13.1 software (StatSoft, Tulsa, OK, USA). Lymphangioma in the analyzed material coexisted with abnormalities in fetal echo in 78% (n = 25) of cases, especially: heart defect in 50% (n = 16) and with normal heart structure with functional changes in 28% (n = 9). Karyotype was available in 50% of the analyzed cases (n = 16). Normal cytogenetic results were observed in 62.5% (n = 10) of cases. In the remaining cases, the following were observed: Turner Syndrome: 25% (n = 4) and Down Syndrome 12.5% (n = 2). The rate of alive newborns was significantly higher among fetuses with isolated lymphangioma in comparison to those with lymphangioma associated with abnormal ECHO examination: 38.46% (n = 5) vs. 15.38% (n = 2; p = 0.037). Abnormal ECHO exam was a poor prognostic sign for fetuses with lymphangioma; therefore, we think it is important to refer these cases for detailed echocardiography in tertiary centers. Moreover, it should be highlighted that in all lymphangioma cases there was an indication to perform the karyotype assessment, as there was a high risk of aneuploidy.

New Molecular and Organelle Alterations Linked to Down Syndrome Heart Disease

Down syndrome (DS) is a genetic disorder caused by a trisomy of the human chromosome 21 (Hsa21). Overexpression of Hsa21 genes that encode proteins and non-coding RNAs (ncRNAs) can disrupt several cellular functions and biological processes, especially in the heart. Congenital heart defects (CHDs) are present in 45–50% of individuals with DS. Here, we describe the genetic background of this condition (Hsa21 and non-Hsa21 genes), including the role of ncRNAs, and the relevance of these new players in the study of the pathophysiology of DS heart diseases. Additionally, we discuss several distinct pathways in cardiomyocytes which help maintain a functional heart, but that might trigger hypertrophy and oxidative stress when altered. Moreover, we highlight the importance of investigating how mitochondrial and lysosomal dysfunction could eventually contribute to understanding impaired heart function and development in subjects with the Hsa21 trisomy. Altogether, this review focuses on the newest insights about the gene expression, molecular pathways, and organelle alterations involved in the cardiac phenotype of DS.

What Every Internist-Endocrinologist Should Know about Rare Genetic Syndromes in Order to Prevent Needless Diagnostics, Missed Diagnoses and Medical Complications: Five Years of 'Internal Medicine for Rare Genetic Syndromes'

Patients with complex rare genetic syndromes (CRGS) have combined medical problems affecting multiple organ systems. Pediatric multidisciplinary (MD) care has improved life expectancy, however, transfer to internal medicine is hindered by the lack of adequate MD care for adults. We have launched an MD outpatient clinic providing syndrome-specific care for adults with CRGS, which, to our knowledge, is the first one worldwide in the field of internal medicine. Between 2015 and 2020, we have treated 720 adults with over 60 syndromes. Eighty-nine percent of the syndromes were associated with endocrine problems. We describe case series of missed diagnoses and patients who had undergone extensive diagnostic testing for symptoms that could actually be explained by their syndrome. Based on our experiences and review of the literature, we provide an algorithm for the clinical approach of health problems in CRGS adults. We conclude that missed diagnoses and needless invasive tests seem common in CRGS adults. Due to the increased life expectancy, an increasing number of patients with CRGS will transfer to adult endocrinology. Internist-endocrinologists (in training) should be aware of their special needs and medical pitfalls of CRGS will help prevent the burden of unnecessary diagnostics and under- and overtreatment.

Association of Comorbid with Developmental Quotient in Down Syndrome Children

BACKGROUND: Down syndrome (DS) is the most common genetic disorder in children. Children with DS tend to have various comorbid due to developmental abnormalities of chromosome 21, such as congenital heart defects, hearing loss, otitis media, eye disorders, obstructive sleep apnea, thyroid hormone disorders, gastrointestinal atresia, hip joint dislocation, leukemia, and Hirschsprung’s disease. Moreover, they also show cognitive impairments in concentration, communication, memory, and the ability to carry out tasks. Caput Scale/Clinical Adaptive Test/Clinical Linguistic and Auditory Milestone Scale (CAT-CLAMS) is one of the developmental assessment instruments to screen for cognitive disorders. AIM: Hereby, we aimed to find the association of comorbid with developmental quotient in DS children. Data were obtained from medical record with sample age 0–18 years and suffering from DS. METHODS: This was observational analytic study with cross-sectional approach, conducted in DS children age 0–18 years who were treated in Sanglah Hospital in 2018. Characteristic data and comorbid were obtained from medical record, meanwhile, development status was assessed using Caput Scale/CAT-CLAMS. Chi-square was applied to determine the association between comorbidities and development quotient (DQ) in DS children. RESULTS: A total of 32 children with DS were treated in Sanglah Hospital during 2018 with median age was 2 years old and dominated by female patient (71.9%). Several comorbidities were found such as endocrine disorders in 27 children (84.3%), congenital heart disease (CHD) in 16 children (50%), and other comorbid including microcephaly, congenital cataract, palatoschizis, gastrointestinal defects, and congenital talipes equinovarus in 13 children (40.4%). The most common endocrine disorders was congenital hypothyroidism (81.25%), while the most common CHD was patent ductus arteriosus (25%). Bivariate Chi-square analysis showed significant association between comorbid and DQ (PR = 1.4 [95% CI 0.95–1.97], p = 0.03). CONCLUSION: We found an association between comorbidities and DQ in DS children.

SH3-Binding Glutamic Acid Rich-Deficiency Augments Apoptosis in Neonatal Rat Cardiomyocytes

Congenital heart disease (CHD) is one of the most common birth defects in humans, present in around 40% of newborns with Down’s syndrome (DS). The SH3 domain-binding glutamic acid-rich (SH3BGR) gene, which maps to the DS region, belongs to a gene family encoding a cluster of small thioredoxin-like proteins sharing SH3 domains. Although its expression is confined to the cardiac and skeletal muscle, the physiological role of SH3BGR in the heart is poorly understood. Interestingly, we observed a significant upregulation of SH3BGR in failing hearts of mice and human patients with hypertrophic cardiomyopathy. Along these lines, the overexpression of SH3BGR exhibited a significant increase in the expression of hypertrophic markers (Nppa and Nppb) and increased cell surface area in neonatal rat ventricular cardiomyocytes (NRVCMs), whereas its knockdown attenuated cellular hypertrophy. Mechanistically, using serum response factor (SRF) response element-driven luciferase assays in the presence or the absence of RhoA or its inhibitor, we found that the pro-hypertrophic effects of SH3BGR are mediated via the RhoA–SRF axis. Furthermore, SH3BGR knockdown resulted in the induction of apoptosis and reduced cell viability in NRVCMs via apoptotic Hippo–YAP signaling. Taking these results together, we here show that SH3BGR is vital for maintaining cytoskeletal integrity and cellular viability in NRVCMs through its modulation of the SRF/YAP signaling pathways.

Gain in growth after surgical repair of congenital heart disease among children with Down syndrome

Down syndrome (DS) is a common genetic disorder among Saudi children, for which limited data is available on growth for those who undergo surgery for congenital heart disease (CHD). We assessed the magnitude of growth over time following surgery and the factors associated with growth change. Eighty-eight children with DS and CHD who underwent surgery between 2009 and 2017 at the tertiary children's hospital in Al-Qassim, Saudi Arabia, were eligible. Information on gender, height, and weight (at surgery, 6 and 12 months), age at surgery, and type of CHD were abstracted from the medical records. Repeated measure analysis of variance (ANOVA) was used for data analysis. The sample's mean age (SD) was 16.2 months (20.1); 47% were male. Height, weight, and body mass index (BMI) increased significantly at both follow-up points. There was a significant interaction between age at surgery, type of heart disease, and time for all three physical indices (p-values <0.001). The increase in height, weight, and BMI was significantly greater for children ≤8 months old with acyanotic CHD compared to children >8 months with cyanotic CHD. Overall, the gain in growth was greater for the children with DS who had had surgery at a younger age.

Clinical Profiles, Congenital Heart Disease, and Other Comorbidities Among Egyptian Children with Down Syndrome: A Tertiary Center Study

Introduction Down syndrome (DS) is the most common chromosomal disorder. It is accompanied by several comorbidities, which could lead to severe morbidity and mortality. Congenital heart disease (CHD) is one of the most commonly described condition.

Objective This study aimed to determine clinical profiles, dysmorphic features, CHD, and DS associated comorbidities in a tertiary center (Cairo, Egypt).

Patients and Methods This descriptive study included 290 patients diagnosed with DS, who presented to the Clinical Genetics clinic, Cairo University Children Hospitals, from February 2018 to December 2019. The patients' ages ranged from 2 to 4 years old. All patients were evaluated by full history, clinical examination, anthropometric measurements, and assessment of developmental milestones. Patients' diagnostic investigations including karyotype, thyroid function, and echocardiography were checked.

Results The study population consisted of 290 children with DS of which 196 (67.6%) were male, 115 (40%) had CHD, the most prevalent atrial septal defect (ASD), patent ductus arteriosus (PDA), and ventricular septal defect (VSD) accounting for 10.7, 7.1, and 4.2%, respectively. Common dysmorphic features were upward slanting palpebral fissures (98.6%), hypertelorism (97.9%), and sandal gap (60.7%). Thyroid dysfunction was the second prevalent comorbidity, found in 35 patients (12.1%). Global developmental delay was reported affecting language (99%), motor (94.8%), and social (92.8%) domains.

Conclusion The prevalence of CHD among children with DS was 40% with ASD, PDA, and VSD being the commonest. Thyroid dysfunction was the second most common comorbidity. The most prevalent dysmorphic features were upward slanting palpebral fissures, hypertelorism, and sandal gap. Developmental delay was very common, language being the most affected domain.

Clinical Phenotypic Spectrum of 4095 Individuals with Down Syndrome from Text Mining of Electronic Health Records

Human genetic disorders, such as Down syndrome, have a wide variety of clinical phenotypic presentations, and characterizing each nuanced phenotype and subtype can be difficult. In this study, we examined the electronic health records of 4095 individuals with Down syndrome at the Children’s Hospital of Philadelphia to create a method to characterize the phenotypic spectrum digitally. We extracted Human Phenotype Ontology (HPO) terms from quality-filtered patient notes using a natural language processing (NLP) approach MetaMap. We catalogued the most common HPO terms related to Down syndrome patients and compared the terms with those from a baseline population. We characterized the top 100 HPO terms by their frequencies at different ages of clinical visits and highlighted selected terms that have time-dependent distributions. We also discovered phenotypic terms that have not been significantly associated with Down syndrome, such as “Proptosis”, “Downslanted palpebral fissures”, and “Microtia”. In summary, our study demonstrated that the clinical phenotypic spectrum of individual with Mendelian diseases can be characterized through NLP-based digital phenotyping on population-scale electronic health records (EHRs).

[Congenital heart disease associated with the most prevalent chromosomal syndromes: a literature review]

Most frequent chromosomal syndromes like Down, Patau, Edwards, Turner, and Williams affect the pediatric population in various ways, and congenital heart disease explains the altered quality of life they suffer. There is a lack of studies reviewing the cardiac anomalies in these syndromes, and the ones that exist are publications from past decades. We reviewed databases such as MEDLINE, LILACS, SCIELO, and Google Scholar, selecting the best possible evidence, and each chromosomal syndrome was investigated in relation to congenital heart disease, constituting five search groups. The article shows the characteristics of each heart disease described in the studies reviewed, the author, date of publication, country, and population studied, as well as a brief description of the frequency of the disease and its mortality. The results described in this review were contrasted with previous existing literature to verify if there was correspondence between the reported frequencies. The most frequent congenital heart diseases were atrioventricular septal defect (AVSD), ventricular septal defect (VSD), atrial septal defect (ASD), and persistent ductus arteriosus (PDA) in Down syndrome patients, PDA, ASD, and VSD in Patau syndrome patients, AVSD, PDA and valvular defects in Edwards syndrome, bicuspid aortic valve, aortic coarctation and aortic stenosis in Turner syndrome, and supravalvular aortic stenosis and pulmonary stenosis in Williams syndrome.

Pattern of congenital heart disease among Egyptian children: a 3-year retrospective study

BACKGROUND

Congenital heart disease (CHD) is a multifactorial birth defect which has variable demographic characteristics among children in different geographical areas. This study aimed to detect the distribution of demographic data, perinatal risk factors, types, age, and mode of presentation of CHD among Egyptian children.

RESULTS

The medical records of 1005 patients were included. They were 545 males (54%) and 462 females (46%) with a ratio of 1.2:1. Acyanotic CHD was encountered in 79.2%. Isolated ventricular septal defect and tetralogy of Fallot were the most common acyanotic and cyanotic lesions, respectively. The majority was diagnosed within the first year of life (86.7%) and was born to young mothers (91.3%). The accidental discovery of a murmur was the most frequent presentation (35%). Heart failure was detected in 44%, audible murmurs in 74.4%, maternal illnesses in 54%, consanguinity in 44.6%, prematurity in 19.3%, assisted reproduction in 11.7%, family history of CHD in 9.2%, abortions in 7.1%, and extracardiac anomalies in 3.6% of the studied population. Down syndrome (DS) was the most commonly occurring chromosomal anomaly, and the atrioventricular septal defect was the most characteristic cardiac lesion found among them.

CONCLUSIONS

There is no sex predilection among Egyptian children with CHD. Most of the cases are diagnosed in early infancy. Accidental discovery of a murmur is the most common mode of presentation. A variety of predisposing risk factors are abundant in the Egyptian population. DS is the most common chromosomal anomaly linked to CHD. Establishment of a national medical birth registry containing all information about all births in Egypt is needed for adequate surveillance and monitoring of perinatal health problems and congenital birth defects so that preventive measures can be early implemented. Proper and detailed data collection should be fulfilled in the medical records of every single patient.

Congenital heart disease in Down syndrome – A review of temporal changes

Background

Congenital heart disease (CHD) is a well-known co-occurring condition in Down syndrome (DS). We aimed to review the literature to evaluate the current evidence to address key questions.

Methods

A series of key questions were formulated a priori to inform the search strategy and review process. These addressed the topics of prevalence, type of CHD, severity, and screening. Using the National Library of Medicine database, PubMed, detailed literature searches were performed. The quality of available evidence was then evaluated, the existing literature was summarized, and knowledge gaps were identified.

Results

Fifty-six relevant original articles were identified which addressed at least one key question. Study details, including: research design, internal validity, external validity, and relevant results are presented. The total prevalence of CHD reported in DS ranged from 20 to 57.9%. In later decades, the prevalence remained constant at 40—55%. The types and classification of CHD varied considerably between studies. Some studies indicate a trend towards a milder phenotype, but this was not consistent. Over time, some studies observed an improved prognosis for CHD in DS. Studies investigating screening for CHD by physical examination, chest X-ray, and electrocardiogram report sensitivities of 71–95%.

Conclusion

To further improve knowledge on CHD in DS, we suggest that future studies cover a wide range of nations and regions, with a longitudinal design, and account for potential confounding factors.

Types and Distribution of Congenital Heart Defects in Pediatric Patients with Down’s Syndrome: A Retrospective Study

Background

Congenital heart disease (CHD) is common in patients with Down’s syndrome (DS), rendering them at risk of significant mortality and morbidity. However, all patients with confirmed DS must undergo further investigation for a cardiac anomaly early in their lives.

Objective

To define frequency and patterns of CHD among children with DS in Northwest, Saudi Arabia (SA).

Methods

A five-year chart review study was conducted in Northwest SA between January 2015 and June 2019. We included all children referred to the pediatric cardiology clinic with a confirmed diagnosis of DS and CHD. Children were identified in the clinic’s database, and charts were reviewed retrospectively. 

Results

Among 851 patients with CHD, 53 were identified with DS. Male patients represented 62.3%, while female patients represented 37.7%. The median patients’ age at the time of diagnosis was two days, with most patients diagnosed before 28 days old (67.9%). This study found that atrial septal defect (ASD) and patent ductus arteriosus (PDA) were the most common isolated lesions (37% of isolated cases), while the most common combined lesions were ASD, ventricular septal defect (VSD), and PDA, as well as combined ASD and VSD. Female gender was significantly associated with higher percentage of VSD (p = 0.031) more than male. While male patients had significantly higher percentages of ASD and valvular anomalies than female patients (p = 0.019 and 0.033, respectively).

Conclusions

The patient’s gender was significantly associated with some types of CHD. Both ASD and valvular lesions were more common among males, while VSD was more common among female patients, no gender differences were detected regarding the other types of CHD.

Trisomy 21 and Ebstein Anomaly: Diagnosis and Prognosis of a Rare Association

Trisomy 21 is considered the most common chromosomal aneuploidy, and congenital heart disease (CHD) is highly prevalent and relevant to the morbidity and mortality of these patients. Ebstein anomaly (EA) is a rare CHD characterized by tricuspid valve dysplasia with inferior septal leaflet displacement. Herein, we described a patient with trisomy 21 who presented with EA and discuss the association between the two conditions based on a literature review. We conclude that the concomitant occurrence of both conditions is considered to be rare. These individuals are most frequently diagnosed during birth and childhood, and they usually have a good prognosis, as observed with our patient and is typical for EA patients in general. However, it is important to be aware that electrophysiologic anomalies may also be present.

Major Septal Defects: Comparative Study of Down Syndrome and Non-Down Syndrome Infants, Before and After Surgery

Objective:

To compare pre-operative, intra-operative, and post-operative parameters in Down syndrome (DS) and non-DS patients with atrioventricular septal defects (AVSD) and inlet ventricular septal defects (VSD) in a tertiary care hospital in Pakistan.

Methods:

We conducted a retrospective study at Aga Khan University, Pakistan. All complete atrioventricular septal defect (CAVSD), partial atrioventricular septal defect (PAVSD), and VSD with inlet extension surgical cases from January 2007 to January 2019 were included. Patients with congenital heart diseases other than those listed above were excluded.

Results:

In 61 cases, 18 had DS. Median age, mean body surface area (BSA), and height were lower in DS patients compared to non-DS patients: 7.0 vs 23.0 months, 0.311 vs 0.487 m2, and 63 vs 82 cm, respectively. Bypass duration, aortic cross clamp time, post-operative ventilator hours, dose of inotropes, CICU stay, and total hospital stay were all significantly higher in the DS group. The odds ratio (955% CI) for mortality in DS babies was 6.2 (1.4, 27.1), p=0.015, after adjusting for age, weight, and height. The overall morbidity was comparable between the two groups, demonstrating no significant difference after adjusting for confounders.

Conclusion:

DS babies with AVSD and inlet VSD are at a greater risk of mortality compared to non-DS babies, particularly those with CAVSD. Furthermore, DS babies undergo surgery at a younger age and require more aggressive post-operative therapy and monitoring due to the development of complications.

Differences in morbidity and mortality in Down syndrome are related to the type of congenital heart defect

Morbidity and mortality in Down syndrome (DS) are mainly related to congenital heart defects (CHDs). While CHDs with high prevalence in DS (typical CHDs), such as endocardial cushion defects, have been extensively described, little is known about the impact of less common CHDs (atypical CHDs), such as aortic coarctation and univentricular hearts. In our single-center study, we analyzed, in observational, retrospective manner, data regarding cardiac features, surgical management, and outcomes of a cohort of DS patients. Literature review was performed to investigate previously reported studies on atypical CHDs in DS. Patients with CHDs were subclassified as having typical or atypical CHDs. Statistical analysis was performed for comparison between the groups. The study population encompassed 859 DS patients, 72.2% with CHDs, of which 4.7% were atypical. Statistical analysis showed a significant excess in multiple surgeries, all-cause mortality and cardiac mortality in patients with atypical CHDs (p = .0067, p = .0038, p = .0001, respectively). According to the Kaplan-Meier method, survival at 10 and 40 years was significantly higher in typical CHDs (99 and 98% vs. 91 and 84%, log rank <0.05). Among atypical CHDs, it seems that particularly multiple complex defects in univentricular physiology associate with a worse outcome. This may be due to the surgical difficulty in managing univentricular hearts with multiple defects concurring to the clinical picture or to the severity of associated defects themselves. Further studies need to address this specific issue, also considering the higher pulmonary pressures, infective complications, and potential comorbidities in DS patients.

Congenital heart diseases: genetics, non-inherited risk factors, and signaling pathways

Background

Congenital heart diseases (CHDs) are the most common congenital anomalies with an estimated prevalence of 8 in 1000 live births. CHDs occur as a result of abnormal embryogenesis of the heart. Congenital heart diseases are associated with significant mortality and morbidity. The damage of the heart is irreversible due to a lack of regeneration potential, and usually, the patients may require surgical intervention. Studying the developmental biology of the heart is essential not only in understanding the mechanisms and pathogenesis of congenital heart diseases but also in providing us with insight towards developing new preventive and treatment methods.

Main body

The etiology of congenital heart diseases is still elusive. Both genetic and environmental factors have been implicated to play a role in the pathogenesis of the diseases. Recently, cardiac transcription factors, cardiac-specific genes, and signaling pathways, which are responsible for early cardiac morphogenesis have been extensively studied in both human and animal experiments but leave much to be desired. The discovery of novel genetic methods such as next generation sequencing and chromosomal microarrays have led to further study the genes, non-coding RNAs and subtle chromosomal changes, elucidating their implications to the etiology of congenital heart diseases. Studies have also implicated non-hereditary risk factors such as rubella infection, teratogens, maternal age, diabetes mellitus, and abnormal hemodynamics in causing CHDs.

These etiological factors raise questions on multifactorial etiology of CHDs. It is therefore important to endeavor in research based on finding the causes of CHDs. Finding causative factors will enable us to plan intervention strategies and mitigate the consequences associated with CHDs. This review, therefore, puts forward the genetic and non-genetic causes of congenital heart diseases. Besides, it discusses crucial signaling pathways which are involved in early cardiac morphogenesis. Consequently, we aim to consolidate our knowledge on multifactorial causes of CHDs so as to pave a way for further research regarding CHDs.

Conclusion

The multifactorial etiology of congenital heart diseases gives us a challenge to explicitly establishing specific causative factors and therefore plan intervention strategies. More well-designed studies and the use of novel genetic technologies could be the way through the discovery of etiological factors implicated in the pathogenesis of congenital heart diseases.

Whole Exome Sequencing Reveals the Major Genetic Contributors to Nonsyndromic Tetralogy of Fallot

RATIONALE

Familial recurrence studies provide strong evidence for a genetic component to the predisposition to sporadic, nonsyndromic Tetralogy of Fallot (TOF), the most common cyanotic congenital heart disease phenotype. Rare genetic variants have been identified as important contributors to the risk of congenital heart disease, but relatively small numbers of TOF cases have been studied to date.

OBJECTIVE

We used whole exome sequencing to assess the prevalence of unique, deleterious variants in the largest cohort of nonsyndromic TOF patients reported to date.

METHODS AND RESULTS

Eight hundred twenty-nine TOF patients underwent whole exome sequencing. The presence of unique, deleterious variants was determined; defined by their absence in the Genome Aggregation Database and a scaled combined annotation-dependent depletion score of ≥20. The clustering of variants in 2 genes, NOTCH1 and FLT4, surpassed thresholds for genome-wide significance (assigned as P<5×10^-8) after correction for multiple comparisons. NOTCH1 was most frequently found to harbor unique, deleterious variants. Thirty-one changes were observed in 37 probands (4.5%; 95% CI, 3.2%-6.1%) and included 7 loss-of-function variants 22 missense variants and 2 in-frame indels. Sanger sequencing of the unaffected parents of 7 cases identified 5 de novo variants. Three NOTCH1 variants (p.G200R, p.C607Y, and p.N1875S) were subjected to functional evaluation, and 2 showed a reduction in Jagged1-induced NOTCH signaling. FLT4 variants were found in 2.4% (95% CI, 1.6%-3.8%) of TOF patients, with 21 patients harboring 22 unique, deleterious variants. The variants identified were distinct to those that cause the congenital lymphoedema syndrome Milroy disease. In addition to NOTCH1, FLT4 and the well-established TOF gene, TBX1, we identified potential association with variants in several other candidates, including RYR1, ZFPM1, CAMTA2, DLX6, and PCM1.

CONCLUSIONS

The NOTCH1 locus is the most frequent site of genetic variants predisposing to nonsyndromic TOF, followed by FLT4. Together, variants in these genes are found in almost 7% of TOF patients.

Blood-based biomarkers for Down syndrome and Alzheimer's disease: A systematic review

Down syndrome (DS) occurs due to triplication of chromosome 21. Individuals with DS face an elevated risk for development of Alzheimer's disease (AD) due to increased amyloid beta (Aβ) resulting from the over-expression of the amyloid precursor protein found on chromosome 21. Diagnosis of AD among individuals with DS poses particular challenges resulting in an increased focus on alternative diagnostic methods such as blood-based biomarkers. The aim of this review was to evaluate the current state of the literature of blood-based biomarkers found in individuals with DS and particularly among those also diagnosed with AD or in prodromal stages (mild cognitive impairment [MCI]). A systematic review was conducted utilizing a comprehensive search strategy. Twenty-four references were identified, of those, 22 fulfilled inclusion criteria were selected for further analysis with restriction to only plasma-based biomarkers. Studies found Aβ to be consistently higher among individuals with DS; however, the link between Aβ peptides (Aβ1-42 and Aβ1-40) and AD among DS was inconsistent. Inflammatory-based proteins were more reliably found to be elevated leading to preliminary work focused on an algorithmic approach with predominantly inflammatory-based proteins to detect AD and MCI as well as predict risk of incidence among DS. Separate work has also shown remarkable diagnostic accuracy with the use of a single protein (NfL) as compared to combined proteomic profiles. This review serves to outline the current state of the literature and highlights the potential plasma-based biomarkers for use in detecting AD and MCI among this at-risk population.

HDAC1-mediated repression of the retinoic acid-responsive gene ripply3 promotes second heart field development

Coordinated transcriptional and epigenetic mechanisms that direct development of the later differentiating second heart field (SHF) progenitors remain largely unknown. Here, we show that a novel zebrafish histone deacetylase 1 (hdac1) mutant allele cardiac really gone (crg) has a deficit of ventricular cardiomyocytes (VCs) and smooth muscle within the outflow tract (OFT) due to both cell and non-cell autonomous loss in SHF progenitor proliferation. Cyp26-deficient embryos, which have increased retinoic acid (RA) levels, have similar defects in SHF-derived OFT development. We found that nkx2.5⁺ progenitors from Hdac1 and Cyp26-deficient embryos have ectopic expression of ripply3, a transcriptional co-repressor of T-box transcription factors that is normally restricted to the posterior pharyngeal endoderm. Furthermore, the ripply3 expression domain is expanded anteriorly into the posterior nkx2.5⁺ progenitor domain in crg mutants. Importantly, excess ripply3 is sufficient to repress VC development, while genetic depletion of Ripply3 and Tbx1 in crg mutants can partially restore VC number. We find that the epigenetic signature at RA response elements (RAREs) that can associate with Hdac1 and RA receptors (RARs) becomes indicative of transcriptional activation in crg mutants. Our study highlights that transcriptional repression via the epigenetic regulator Hdac1 facilitates OFT development through directly preventing expression of the RA-responsive gene ripply3 within SHF progenitors.

Congenital heart defects are the most common malformations found in newborns, with many of these defects disrupting development of the outflow tract, the structure where blood is expelled from the heart. Despite their frequency, we do not have a grasp of the molecular and genetic mechanisms that underlie most congenital heart defects. Here, we show that zebrafish embryos containing a mutation in a gene called histone deacetylase 1 (hdac1) have smaller hearts with a reduction in the size of the ventricle and outflow tract. Hdac1 proteins limit accessibility to DNA and repress gene expression. We find that loss of Hdac1 in zebrafish embryos leads to increased expression of genes that are also induced by excess retinoic acid, a teratogen that induces similar outflow tract defects. Genetic loss-of-function studies support that ectopic expression of ripply3, a common target of both Hdac1 and retinoic acid signaling that is normally restricted to a subset of posterior pharyngeal cells, contributes to the smaller hearts found in zebrafish hdac1 mutants. Our study establishes a mechanism whereby the coordinated repression of genes downstream of Hdac1 and retinoic acid signaling is necessary for normal vertebrate outflow tract development.

Sleep and sleep disordered breathing in children with down syndrome: Effects on behaviour, neurocognition and the cardiovascular system

Down syndrome (DS), the most common human chromosomal malformation, has an estimated annual incidence of one in 1000 live births worldwide. Sleep problems are common in children with DS, reported by parents in up to 65% of school-aged children, significantly higher rates than in typically developing (TD) children. Problems include difficulty in sleep initiation and maintenance together with obstructive sleep apnoea (OSA) which affects up to over 90%, of DS children compared with 1-5% in the general paediatric population. Any sleep problem has the potential to exert significant negative effects on daytime behaviour, learning and quality of life in TD children and there is now a growing body of evidence that children with DS are similarly affected. In addition to adverse effects on daytime functioning, OSA has adverse effects on the cardiovascular system and this is a particularly significant issue given the high rates of hypertension and premature cardiac disease in people with DS. This review discusses the effects of sleep problems and OSA on daytime functioning and cardiovascular function in children with DS and evidence of the effectiveness of treatment in improving outcomes and quality of life for these children.

Genomics and Epigenomics of Congenital Heart Defects: Expert Review and Lessons Learned in Africa

Congenital heart defects (CHD) are structural malformations found at birth with a prevalence of 1%. The clinical trajectory of CHD is highly variable and thus in need of robust diagnostics and therapeutics. Major surgical interventions are often required for most CHDs. In Africa, despite advances in life sciences infrastructure and improving education of medical scholars, the limited clinical data suggest that CHD detection and correction are still not at par with the rest of the world. But the toll and genetics of CHDs in Africa has seldom been systematically investigated. We present an expert review on CHD with lessons learned on Africa. We found variable CHD phenotype prevalence in Africa across countries and populations. There are important gaps and paucity in genomic studies of CHD in African populations. Among the available genomic studies, the key findings in Africa were variants in GATA4 (P193H), MTHFR 677TT, and MTHFR 1298CC that were associated with atrial septal defect, ventricular septal defect (VSD), Tetralogy of Fallot (TOF), and patent ductus arteriosus phenotypes and 22q.11 deletion, which is associated with TOF. There were no data on epigenomic association of CHD in Africa, however, other studies have shown an altered expression of miR-421 and miR-1233-3p to be associated with TOF and hypermethylation of CpG islands in the promoter of SCO2 gene also been associated with TOF and VSD in children with non-syndromic CHD. These findings signal the urgent need to develop and implement genetic and genomic research on CHD to identify the hereditary and genome-environment interactions contributing to CHD. These projected studies would also offer comparisons on CHD pathophysiology between African and other populations worldwide. Genomic research on CHD in Africa should be developed in parallel with next generation technology policy research and responsible innovation frameworks that examine the social and political factors that shape the emergence and societal embedding of new technologies.

Dynamics in prevalence of Down syndrome in children with congenital heart disease

We assessed the dynamics in the prevalence of children with congenital heart disease (CHD) and Down syndrome in Germany with regard to phenotype, severity, and gender. Data from patients with CHD and Down syndrome born between 1980 and 2014 were analyzed, who are registered with the German National Register for Congenital Heart Defects. One thousand six hundred eighteen CHD patients with Down syndrome were identified. The prevalence of children born with both Down syndrome and CHD was constant from 2005 to 2009 but increased from 2010 to 2014. Regarding CHD groups, complex and simple lesions have become more equal since 2005. The number of simple lesions with shunt has a peak prevalence in the period of 2010-2014. Atrioventricular septal defect was the most common CHD phenotype, but temporal changes were found within the group of CHD phenotypes over the observation period.

CONCLUSION

Our findings suggest a growing number of CHD and Down syndrome, which may be the result of improved medical management and progress in educational, social, and financial support. This development is noteworthy as it adds new aspects to present discussions in the media and political settings. What is known: • Congenital heart disease is regarded to be the most important clinical phenomenon in children with Down syndrome, due to its significant impact on morbidity and mortality. • New developments in prenatal diagnostic and therapy management of congenital heart disease continue to influence the number of patients diagnosed with congenital heart disease and Down syndrome. What is New: • This study provides essential data giving the first overview of the dynamics in the prevalence of congenital heart disease and Down syndrome over an extended length of time up to 2015 in a large patient cohort, taking recent developments into account. • Our data suggest a growing prevalence of congenital heart disease and Down syndrome, which may be the result of improved medical management for Down syndrome patients and progress in educational, social, and financial support for their families; this development is noteworthy as it adds new aspects to the present discussion in the media and political settings.