Cardiovascular disease in Down syndrome

Feeding practices and dietary intake in Brazilian children with Down syndrome: A cross-sectional study

BACKGROUND

Studies investigating the quality of the diet and dietary intake of children with Down syndrome (DS) are required because the features attributed to the syndrome can affect growth, development and quality of life.

METHODS

This cross-sectional study was conducted with 77 Brazilian children with DS between 5 and 36 months of age receiving care at the multidisciplinary outpatient clinic of the University Hospital. Participants' sociodemographic, dietary and anthropometric data were collected from the care protocols. Dietary data were collected from 24-h recalls and dietary practices were assessed according to the WHO dietary guidelines. Associations between inadequate feeding practices and demographic variables were assessed using logistic regression models.

RESULTS

Fruits, milk or infant formula, vegetables, beans and meat were among the five most consumed foods by the children investigated. Overall, we observed a high number of cases of early weaning (50.6%), low minimum dietary diversity (MDD; 40.3%), inadequate consistency for age (64.9%), early presence of ultra-processed foods (76.6%), sugars and sweets (33.8%) in the diet of the children with DS. In the associations of inadequate feeding practices by age group, low MDD [odds ratio (OR): 18.6; 95% confidence interval (CI): 3.4; 57.1] and inadequate consistency (OR: 6.65; 95% CI: 1.8; 24.7) were more frequent among children aged below 12 months while this relationship was inverse for early introduction of sugar and sweets (OR: 0.04; 95% CI: 0.01; 0.29).

CONCLUSION

Our findings showed a high number of cases of inadequate dietary practices in children with DS investigated, which could adversely affect the long-term health of this population.

Embryonic statistical analyses reveal 2 growth phenotypes in mouse models of Down syndrome

BACKGROUND

Down syndrome is associated with several comorbidities, including intellectual disability, growth restriction, and congenital heart defects. The prevalence of Down syndrome-associated comorbidities is highly variable, and intellectual disability, although fully penetrant, ranges from mild to severe. Understanding the basis of this interindividual variability might identify predictive biomarkers of in utero and postnatal outcomes that could be used as endpoints to test the efficacy of future therapeutic interventions.

OBJECTIVE

The main objective of this study was to examine if antenatal interindividual variability exists in mouse models of Down syndrome and whether applying statistical approaches to clinically relevant measurements (ie, the weights of the embryo, placenta, and brain) could define cutoffs that discriminate between subgroups of trisomic embryos.

STUDY DESIGN

Three commonly used mouse models of Down syndrome (Dp(16)1/Yey, Ts65Dn, and Ts1Cje) and a new model (Ts66Yah) were used in this study. Trisomic and euploid littermate embryos were used from each model with total numbers of 102 for Ts66Yah, 118 for Dp(16)1/Yey, 92 for Ts65Dn, and 126 for Ts1Cje. Placental, embryonic, and brain weights and volumes at embryonic day 18.5 were compared between genotypes in each model. K-mean clustering analysis was applied to embryonic and brain weights to identify severity classes in trisomic embryos, and brain and placental volumetric measurements were compared between genotypes and classes for each strain. In addition, Ts66Yah embryos were examined for malformations because embryonic phenotypes have never been examined in this model.

RESULTS

Reduced body and brain weights were present in Ts66Yah, Dp(16)1/Yey, and Ts65Dn embyos. Cluster analysis identified 2 severity classes in trisomic embryos-mild and severe-in all 4 models that were distinguishable using a putative embryonic weight cutoff of <0.5 standard deviation below the mean. Ts66Yah trisomic embryos develop congenital anomalies that are also found in humans with Down syndrome, including congenital heart defects and renal pelvis dilation.

CONCLUSION

Statistical approaches applied to clinically relevant measurements revealed 2 classes of phenotypic severity in trisomic mouse models of Down syndrome. Analysis of severely affected trisomic animals may facilitate the identification of biomarkers and endpoints that can be used to prenatally predict outcomes and the efficacy of treatments.

Impact of Down Syndrome on Survival Among Patients With Congenital Heart Disease

BACKGROUND

Increasing survival among patients with congenital heart disease (CHD) has recently been reported. However, the impact of Down syndrome (DS) in patients with CHD is still debated. We aimed to estimate survival in patients with CHD with versus without DS compared with matched controls from the general population without CHD or DS.

METHODS AND RESULTS

We linked data from Swedish health registries to identify patients with CHD born between 1970 and 2017. Data from the Total Population Register were used to match each patient with CHD by sex and birth year with 8 controls without CHD or DS. A Cox proportional regression model was used to estimate mortality risk, and Kaplan-Meier curves were analyzed for the survival analysis. We identified 3285 patients with CHD-DS, 64 529 patients with CHD without DS, and 26 128 matched controls. The mortality risk was 25.1 times higher (95% CI, 21.3-29.5) in patients with CHD-DS versus controls. The mortality rate was 2 times higher (95% CI, 1.94-2.31) for patients with CHD with versus without DS. Lower mortality was found during the second versus first birth periods in patients with CHD-DS compared with controls; hazard ratio: 46.8 (95% CI, 29.5-74.0) and 17.7 (95% CI, 12.8-24.42) in those born between 1970 and 1989 versus 1990 and 2017, respectively.

CONCLUSIONS

In this retrospective cohort study, the mortality risk among patients with CHD-DS was 25 times higher compared with matched controls and 2 times higher compared with patients with CHD without DS. Survival was higher in patients with CHD-DS born after versus before 1990, coinciding with the modern era of congenital heart care.

Effects of exercise programs on cardiovascular responses in individuals with down syndrome: A systematic review and meta-analysis

The purpose of this study is to conduct a systematic review and meta-analysis of exercise interventions designed to improve cardiovascular responses in individuals with DS. A search for relevant articles was conducted on seven electronic databases: PubMed, PEDro, Google Scholar, Scopus, WOS, MEDLINE, and SPORT Discus. An electronic search was conducted on October 15, 2022, without applying any year constraints. The studies were chosen based on a predetermined set of inclusion and exclusion criteria. The methodology of the study was evaluated using the PEDro scale, and data analyses were conducted using the CMA v3 random effects model. In total, 625 articles were reviewed, and data from 10 randomized controlled trials (RCTs) involving DS were used in this meta-analysis. The results showed that exercise programs were effective in increasing VO2peak (ml. kg -1min-1) (ES: 0.69; 95 % confidence interval [CI], 0.27-1.12; P: 0.001), time to exhaustion (ES: 0.83; CI, 0.31-1.35, P: 0.001), and VEpeak (ES: 0.76; CI, 0.32-1.20; P: 0.001). No changes were found for HRpeak (ES: 0.3; CI, -0.02-0.63, P: 0.07), VO2peak (ml·min-1) (ES: 0.45; CI, -0.01-0.92; P: 0.06), or RER (ES: 0.45; CI, -0.09-0.98, P: 0.10). No adverse effects were reported in any of the studies. In this meta-analysis and comprehensive review, exercise interventions may improve cardiovascular responses in DS; however, the association wasn't consistent across trials. RCTs with precise intervention criteria, large sample sizes, and long-term follow-up are needed in the future to demonstrate the benefits of exercise on cardiovascular responses in people with DS.

Long-Term Non-Congenital Cardiac and Renal Complications in Down Syndrome: A Study of 32,936 Patients

BACKGROUND

Individuals with Down syndrome are at a higher risk of cardiac, renal, and other health issues due to a complex disease physiology. However, few data exist on long-term disease risks to guide prevention and care. We aimed to determine the 10-year incidence of cardiac, renal, and urinary tract complications in Down syndrome versus matched controls.

METHODS

This retrospective cohort study utilized a large collaborative database. We identified 32,444 patients with Down syndrome and matched controls, excluding those with pre-follow-up target events. Covariates included demographics, lifestyle factors, and comorbidities. Outcomes were ischemic heart disease, hypertension, hypothyroidism, epilepsy, urinary tract infections and chronic kidney disease. We calculated unadjusted and adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox regression and plotted Kaplan-Meier survival curves.

FINDINGS

Over 10 years, Down syndrome patients showed a 3.7-fold higher ischemic heart disease risk (95% CI: 3.0-4.6) and a 1.6-fold higher hypertension risk (95% CI: 1.4-1.8) versus controls. Hypothyroidism (HR = 2.0; 95% CI: 1.7-2.4), epilepsy (HR = 4.5; 95% CI: 3.5-5.8), and urinary tract infection (HR = 3.9; 95% CI: 3.4-4.6) risks were also higher. Chronic kidney disease risk was 2.7-fold greater (95% CI: 2.1-3.5). Survival analysis confirmed a significantly higher incidence of all outcomes in Down syndrome (p < 0.0001).

INTERPRETATION

This large study found major health challenges in Down syndrome, with risks 3- to 5-fold higher for chronic conditions versus matched controls over 10 years. Though survival remains high with proper care, focusing resources on the prevention and management of complications in this high-risk group can optimize well-being across the lifespan. Future research accounting for limitations here would provide definitive estimates of disease risk in Down syndrome to guide targeted health strategies.

Comprehensive volumetric phenotyping of the neonatal brain in Down syndrome

Down syndrome (DS) is the most common genetic cause of intellectual disability with a wide range of neurodevelopmental outcomes. To date, there have been very few in vivo neuroimaging studies of the neonatal brain in DS. In this study we used a cross-sectional sample of 493 preterm- to term-born control neonates from the developing Human Connectome Project to perform normative modeling of regional brain tissue volumes from 32 to 46 weeks postmenstrual age, accounting for sex and age variables. Deviation from the normative mean was quantified in 25 neonates with DS with postnatally confirmed karyotypes from the Early Brain Imaging in DS study. Here, we provide the first comprehensive volumetric phenotyping of the neonatal brain in DS, which is characterized by significantly reduced whole brain, cerebral white matter, and cerebellar volumes; reduced relative frontal and occipital lobar volumes, in contrast with enlarged relative temporal and parietal lobar volumes; enlarged relative deep gray matter volume (particularly the lentiform nuclei); and enlargement of the lateral ventricles, amongst other features. In future, the ability to assess phenotypic severity at the neonatal stage may help guide early interventions and, ultimately, help improve neurodevelopmental outcomes in children with DS.

REST Targets JAK-STAT and HIF-1 Signaling Pathways in Human Down Syndrome Brain and Neural Cells

Down syndrome (DS) is the most frequently diagnosed chromosomal disorder of chromosome 21 (HSA21) aneuploidy, characterized by intellectual disability and reduced lifespan. The transcription repressor, Repressor Element-1 Silencing Transcription factor (REST), which acts as an epigenetic regulator, is a crucial regulator of neuronal and glial gene expression. In this study, we identified and investigated the role of REST-target genes in human brain tissues, cerebral organoids, and neural cells in Down syndrome. Gene expression datasets generated from healthy controls and DS samples of human brain tissues, cerebral organoids, NPC, neurons, and astrocytes were retrieved from the Gene Ontology (GEO) and Sequence Read Archive (SRA) databases. Differential expression analysis was performed on all datasets to produce differential expression genes (DEGs) between DS and control groups. REST-targeted DEGs were subjected to functional ontologies, pathways, and network analyses. We found that REST-targeted DEGs in DS were enriched for the JAK-STAT and HIF-1 signaling pathways across multiple distinct brain regions, ages, and neural cell types. We also identified REST-targeted DEGs involved in nervous system development, cell differentiation, fatty acid metabolism and inflammation in the DS brain. Based on the findings, we propose REST as the critical regulator and a promising therapeutic target to modulate homeostatic gene expression in the DS brain.

Sleep disturbances in individuals with down syndrome: An overview

Down Syndrome, or Trisomy 21, is one of the most common birth defects, with 6,000 babies born annually with Down Syndrome in the U.S. One of many health risk factors individuals with Down Syndrome experience is sleep issues, ranging from poor sleep quality to high prevalence of obstructive sleep apnea. This literature review aims to review these sleep challenges in this population and explore consequences and treatment options.

Sex differences in cardiovascular disease and dysregulation in Down syndrome

This meta-analysis, which consisted of a scoping review and retrospective medical record review, is focused on potential sex differences in cardiovascular diseases in patients with Down syndrome. We limited our review to peer-reviewed, primary articles in the English language, in the PubMed and Web of Science databases from 1965 to 2021. Guidelines for scoping reviews were followed throughout the process. Four categorical domains were identified and searched using additional keywords: 1) congenital heart disease, 2) baseline physiology and risk factors, 3) heart disease and hypertension, and 4) stroke and cerebrovascular disease. Articles were included if they reported male and female distinct data, participants with Down syndrome, and one of our keywords. The retrospective medical record review was completed using 75 participating health care organizations to identify the incidence of congenital and cardiovascular diseases and to quantify cardiovascular risk factors in male and female patients. Female patients with Down syndrome are at higher risk of hypertension, ischemic heart disease, and cerebrovascular disease. The risk of congenital heart disease is higher in males with Down syndrome at all ages included in our analyses. Some of the male-to-female sex differences in cardiovascular disease risk in the general patient population are not present, or reversed in the Down syndrome population. This information should be considered for future investigations and ongoing patient care.NEW & NOTEWORTHY In patients with Down syndrome (DS), CHD is the leading cause of death <20 yr old and cardiovascular disease is a leading cause of death in individuals >20 yr old. Men with DS live longer than women. It is unknown if sex differences are present in cardiovascular disease and dysregulation in DS across the lifespan. We observed higher risk of hypertension, ischemic heart disease, and cerebrovascular disease in females and a higher risk of CHD in males with DS.

Anesthetic Considerations for Adult Patients With Both Down Syndrome and Congenital Heart Disease Undergoing Noncardiac Surgery: A Review Article

The population of adult patients with both Down syndrome and congenital heart disease is increasing due to better medical and surgical care. This cohort presents with multiple unique comorbidities, secondary to both progressions of health conditions associated with the aging of patients with Down syndrome, as well as due to pathophysiologic effects of uncorrected, corrected, or palliated congenital heart disease. These patients need frequent medical care and interventions requiring multiple anesthetics. This review focuses on the various factors relevant to the perioperative medical care of adult patients with both Down syndrome and congenital heart disease, founded on existing literature. Various anesthetic considerations for the different patterns of noncardiac and cardiac comorbidities are reviewed, and a systematic approach for the perioperative anesthetic management of these patients is presented.

Down syndrome and biological treatments in dermatology: Efficacy and safety in our real-life experience and review of literature

Down syndrome (DS) is the most common chromosomal disorder; several dermatological conditions are common in these patients; among them, psoriasis and atopic dermatitis can be frequently encountered. From 2017 to today, we retrospectively identified 4 adults and 3 under 18-year-old patients treated with biological drugs, from our research database. The first endpoint of this study was to evaluate whether the biological drugs work in these special population, and a secondary endpoint was to evaluate any loss of efficacy or any side effects during follow-up. All patients were treated with biological drugs experience resolution of their psoriasis. Mean PASI (Psoriasis Area Severity Index), BSA (Body Surface Area) and DLQI (Dermatology Life Quality Index) at baseline were 20, 16.5 and 25. At week 4, mean PASI, BSA and DLQI decreased, respectively, to 8, 6 and 12, while at week 24, mean values were, respectively, 3, 1.3 and 1. The patients that started therapy earlier, at week 52, do not have signs of recurrence and side effects. We highlighted that no official guidelines exist to approach these patients, from a literature evaluation the most employed drugs are anti-TNFα and in particular adalimumab. In our experience, the new anti-interleukin drugs seem to be well-tolerated, with no sides effect, good compliance and no loss of efficacy.

Insights into the Cardiac Phenotype in 9p Deletion Syndrome: A Multicenter Italian Experience and Literature Review

Chromosome 9p deletion syndrome is a rare autosomal dominant disorder presenting with a broad spectrum of clinical features, including congenital heart defects (CHDs). To date, studies focused on a deep characterization of cardiac phenotype and function associated with this condition are lacking. We conducted a multicentric prospective observational study on a cohort of 10 patients with a molecular diagnosis of 9p deletion syndrome, providing a complete cardiological assessment through conventional echocardiography and tissue Doppler imaging echo modality. As a result, we were able to demonstrate that patients with 9p deletion syndrome without major CHDs may display subclinical cardiac structural changes and left-ventricle systolic and diastolic dysfunction. Albeit needing validation in a larger cohort, our findings support the idea that a complete cardiac assessment should be performed in patients with 9p deletion syndrome and should be integrated in the context of a long-term follow-up.

Heart Rate Variability in Individuals with Down Syndrome: A Scoping Review with Methodological Considerations

Individuals with Down syndrome (DS) present similar heart rate variability (HRV) parameters at rest but different responses to selected movement maneuvers in comparison to individuals without DS, which indicates reduced vagal regulation. The present study undertakes a scoping review of research on HRV in individuals with DS, with special attention paid to the compliance of the studies with standards and methodological paper guidelines for HRV assessment and interpretation. A review was performed using PubMed, Web of Science and CINAHL databases to search for English language publications from 1996 to 2020 with the MESH terms "heart rate variability" and "down syndrome", with the additional inclusion criteria of including only human participants and empirical investigations. From 74 studies, 15 were included in the review. None of the reviewed studies met the recommendations laid out by the standards and guidelines for providing the acquisition of RR intervals and necessary details on HRV analysis. Since authors publishing papers on this research topic do not adhere to the prescribed standards and guidelines when constructing the methodology, results of the research papers on the topic are not directly comparable. Authors need to design the study methodology more robustly by following the aforementioned standards, guidelines and recommendations.

Musladin-Lueke Syndrome in a Dog: Case Report

The aim of this study is to report the case of a 4-month-old Beagle dog diagnosed with Musladin-Lueke syndrome. The dog appeared to walk on the digits ("tiptoes") with all limbs during ambulation and rigid extension of the carpus, elbow, tarsus, and knee joints during ambulation. Thickening of the fur and auricular cartilage, reduction in radiocarpal, and tibiotarsal joint amplitude, macrocephaly, and lateralized eyes were noticed on physical examination. Echocardiography showed reduced mobility and altered (tortuous) valve morphology. Bilateral abdominal cryptorchidism was confirmed by ultrasonography. Musladin-Lueke syndrome was the presumptive diagnosis, based on the clinical signs presented. The diagnosis was confirmed after DNA testing performed by serial collection of saliva. This is the first paper that describes unprecedented cardiac and reproductive changes of Musladin-Lueke syndrome in which the dog was followed for 2 years, presenting a good quality of life.

Physical activity, memory function, and hippocampal volume in adults with Down syndrome

Higher engagement in moderate-intensity physical activity (PA) is related to better cognitive functioning in neurotypical adults; however, little is known about the effect of PA on cognitive aging in adults with Down syndrome (DS). Individuals with DS have three copies of chromosome 21, which includes the gene involved in the production of the amyloid precursor protein, resulting in an increased risk for an earlier onset of Alzheimer’s disease (AD). The goal of this study was to understand the relationship between engagement in moderate PA, memory, and hippocampal volume in adults with DS. Adults with DS participated in an ancillary Lifestyle study linked to the Alzheimer’s Biomarkers Consortium for DS (ABC- DS; N = 71). A within-sample z-score memory composite was created from performance on the Cued Recall Test (CRT) and the Rivermead Picture Recognition Test. Participants wore a wrist-worn accelerometer (GT9X) to measure PA. Variables of interest included the average percentage of time spent in moderate PA and average daily steps. Structural MRI data were acquired within 18 months of actigraphy/cognitive data collection for a subset of participants (n = 54). Hippocampal volume was extracted using Freesurfer v5.3. Associations between moderate PA engagement, memory, and hippocampal volume were evaluated with hierarchical linear regressions controlling for relevant covariates [age, body mass index, intellectual disability level, sex, and intracranial volume]. Participants were 37.77 years old (SD = 8.21) and were 55.6% female. They spent 11.1% of their time engaged in moderate PA (SD = 7.5%) and took an average of 12,096.51 daily steps (SD = 4,315.66). After controlling for relevant covariates, higher memory composite score was associated with greater moderate PA engagement (β = 0.232, p = 0.027) and more daily steps (β = 0.209, p = 0.037). In a subset of participants, after controlling for relevant covariates, PA variables were not significantly associated with the hippocampal volume (all p-values ≥ 0.42). Greater hippocampal volume was associated with higher memory composite score after controlling for relevant covariates (β = 0.316, p = 0.017). More PA engagement was related to better memory function in adults with DS. While greater hippocampal volume was related to better memory performance, it was not associated with PA. Greater PA engagement may be a promising lifestyle behavior to preserve memory in adults with DS.

Why Is Health Care for Children with Down Syndrome So Crucial from the First Days of Life? A Retrospective Cohort Study Emphasized Transient Abnormal Myelopoiesis (TAM) Syndrome at Three Centers

Down syndrome (DS) is a common genetic disorder and is associated with an increased likelihood of many diseases, including defects of the heart, genitourinary system, gastrointestinal tract, and oncological diseases. The aim of this study was to analyze medical problems occurring in newborns with DS and to create a basic diagnostic and therapeutic algorithm intended primarily for neonatologists, pediatricians, family physicians, and physicians of other specialties caring for children with DS. Over a 5-year period, the medical records of 161 neonates with Down syndrome from four neonatology departments in Poznan, Poland, were examined. After applying exclusion criteria, 111 patients were analyzed. Data obtained from medical history included sex, week of gestation, birth weight, APGAR score, clinical symptoms, peripheral blood count with smear, and clinical features such as jaundice, hemorrhagic diathesis, ascites, hepato- or splenomegaly, pericardial or pleural effusion, respiratory failure, and other rare transient signs of abnormal myelopoiesis: fetal edema, hepatic fibrosis, renal failure, and rush. In the study group, 8% of children with Down syndrome were diagnosed with a heart and 1.8% with a genitourinary defect. Transient abnormal myelopoiesis syndrome (Transient abnormal myelopoiesis (TAM)) was found in 10% of newborns with DS. A blood count with blood smear, cardiology consultation with echocardiography, and an abdominal ultrasound should be performed in the first few days after birth in all newborns with Down syndrome. If this is not possible and the child's condition is stable, these tests can be performed within 2-3 months after birth.

Preoperative Care of Neonates With Congenital Heart Disease

Congenital heart disease (CHD) is one of the most common types of birth defects, with 40,000 newborns diagnosed yearly in the United States. This article describes: (1) four common heart defects seen in neonatal intensive care units, (2) the typical medical/nursing care of these neonates, and (3) common surgical management for the defects. Hypoplastic left heart syndrome, dextro-transposition of the great arteries, tetralogy of Fallot, and pulmonary atresia with intact ventricular septum are four common types of CHD requiring NICU admission. Knowledge of these defects will help nurses to appropriately manage and treat neonates with these types of CHD.

Cardiovascular Prevention Among Young Adults with Congenital Heart Disease

PURPOSE OF REVIEW

There are over a million adults living with congenital heart disease (CHD) in the USA. There have been improvements in CHD management which have led to an expansion of the adult congenital heart disease (ACHD) population. There is a high prevalence of atherosclerotic cardiovascular disease (ASCVD) encountered in the aging ACHD population. This review focuses on the most recent literature regarding the primary prevention of ASCVD in young ACHD patients.

RECENT FINDINGS

There are unique considerations for ASCVD risk reduction in ACHD patients. ASCVD may be as prevalent in ACHD compared in the general population. However, there may be a perceived shorter life expectancy in ACHD patients; therefore, primary prevention of ASCVD may not be considered important. Preventative strategies for ASCVD are underutilized in ACHD patients. As these patients are followed for a lifetime by cardiologists, we can truly pursue primary prevention in this aging population.

Fifteen-minute consultation: The review of a child with trisomy 21 (Down's syndrome)

Down's syndrome (DS) is the most common chromosomal abnormality seen in live born children and it is the most common genetic cause of intellectual disability. It is associated with abnormalities in many body systems, some of which can cause life threatening complications. This article aims to cover the important aspects to cover when seeing children with DS for their routine follow-up in the neurodevelopmental or general paediatric clinic.

Concomitant pulmonary and neurological embolisation in a Down patient after SARS-CoV-2 vaccine: what is missing?

A 40-year-old Down patient without previous cardiological history was admitted to our institution for dyspnoea after COVID-19 vaccine. CT scan revealed a pulmonary thromboembolism. One week later, he developed neurological impairment and CT scan evidenced a left parietal ischaemic lesion. Concomitantly, he underwent echocardiography showing an atrioventricular septal defect typically associated to Down syndrome and never diagnosed earlier. The diagnosis of paradoxical embolisation was then supposed. Echocardiography also revealed a severe right heart section dilatation, with bidirectional shunt on the septal defects and systemic right heart pressure. Down patients affected by CHD are more prone to develop pulmonary vasculopathy than non-syndromic patients. In this case, the pulmonary vasculopathy was further exacerbated by the pulmonary embolism and by the late diagnosis of CHD. Finally, an appropriate timely diagnosis of atrioventricular septal defect could potentially avoid the neurological complication in this patient.

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.

Trisomy 21, transposition of the great arteries and abnormal myelopoiesis

Down syndrome is a well-recognised genetic condition associated with several comorbidities. Although CHD is common in Down syndrome, transposition of the great arteries is exceptionally rare. We describe a neonate with Down syndrome who presented with transient abnormal myelopoiesis and transposition of the great arteries. Down syndrome may accelerate pulmonary hypertension in transposition of the great arteries and is associated with poor outcomes.

Pediatrics for Disability: A Comprehensive Approach to Children with Syndromic Psychomotor Delay

Intellectual disability is the impairment of cognitive, linguistic, motor and social skills that occurs in the pediatric age and is also described by the term "mental retardation". Intellectual disability occurs in 3-28 % of the general population due to a genetic cause, including chromosome aberrations. Among people with intellectual disabilities, the cause of the disability was identified as a single gene disorder in up to 12 %, multifactorial disorders in up to 4 %, and genetic disorders in up to 8.5 %. Children affected by a malformation syndrome associated with mental retardation or intellectual disability represent a care challenge for the pediatrician. A multidisciplinary team is essential to manage the patient, thereby controlling the complications of the syndrome and promoting the correct psychophysical development. This requires continuous follow-up of these children by the pediatrician, which is essential for both the clinical management of the syndrome and facilitating the social integration of these children.

Role of long non-coding RNAs in Down syndrome patients: a transcriptome analysis study

Down syndrome (DS) is defined by the presence of a third copy of chromosome 21. Several comorbidities can be found in these patients, such as intellectual disability (ID), muscle weakness, hypotonia, congenital heart disease, and autoimmune diseases. The molecular mechanisms playing a role in the development of such comorbidities are still unclear. The regulation and expression of genes that map to chromosome 21 are dynamic and complex, so it is important to perform global gene expression studies with high statistical power to fully characterize the transcriptome in DS patients. This study was undertaken to evaluate mRNAs and lncRNA expression in patients with DS versus a matched cohort of healthy subjects. RNA sequencing was used to perform this transcriptome study. Differential expression analysis revealed 967 transcripts with padj ≤ 0.05. Among them, 447 transcripts were differentially expressed in patients with DS compared to controls. Particularly, 203 transcripts were down expressed (151 protein-coding mRNAs, 45 lncRNAs, 1 microRNA, 1 mitochondrial tRNA, 1 ribozyme, and 1 small nuclear RNA) and 244 were over expressed (210 protein-coding mRNAs and 34 lncRNAs). Interestingly, deregulated lncRNAs are involved in pathways that play a role in developmental disorders, neurological diseases, DNA replication and repair mechanisms, and cancer development in DS patients. In conclusion, these results suggest a role of lncRNAs in the phenotype of DS patients.

Secundum Type Atrial Septal Defect in Patients with Trisomy 21-Therapeutic Strategies, Outcome, and Survival: A Nationwide Study of the German National Registry for Congenital Heart Defects

(1) Secundum type atrial septal defect (ASD II) is usually considered a relatively benign cardiac lesion amenable to elective closure at preschool age. Patients with trisomy 21 (T21), however, are known to have a higher susceptibility for pulmonary vascular disease (PVD). Therefore, T21 children may present with clinical symptoms earlier than those without associated anomalies. In addition, early PVD may even preclude closure in selected T21 patients. (2) We performed a retrospective analysis of the German National Register for Congenital Heart Defects including T21 patients with associated isolated ASD II. We report incidence, demographics, therapeutic strategy, outcome, and survival of this cohort. (3) Of 46,628 patients included in the registry, 1549 (3.3%) had T21. Of these, 156 (49.4% female) had an isolated ASD II. Fifty-four patients (34.6%) underwent closure at 6.4 ± 9.9 years of age. Over a cumulative follow-up (FU) of 1148 patient-years, (median 7.4 years), only one patient developed Eisenmenger syndrome and five patients died. Survival of T21 patients without PVD was not statistically different to age- and gender-matched controls from the normal population (p = 0.62), whereas children with uncorrected T21/ASD II (including patients with severe PVD, in whom ASD-closure was considered contraindicated) showed a significantly higher mortality. (4) The outcome of T21-patients with ASD II and without PVD is excellent. However, PVD, either precluding ASD-closure or development of progressive PVD after ASD-closure, is associated with significant mortality in this cohort. Thus T21 patients with ASD II who fulfill general criteria for closure and without PVD should be offered defect closure analogous to patients without T21.

Congenital Heart Disease: An Immunological Perspective

Congenital heart disease (CHD) poses a significant global health and economic burden-despite advances in treating CHD reducing the mortality risk, globally CHD accounts for approximately 300,000 deaths yearly. Children with CHD experience both acute and chronic cardiac complications, and though treatment options have improved, some remain extremely invasive. A challenge in addressing these morbidity and mortality risks is that little is known regarding the cause of many CHDs and current evidence suggests a multifactorial etiology. Some studies implicate an immune contribution to CHD development; however, the role of the immune system is not well-understood. Defining the role of the immune and inflammatory responses in CHD therefore holds promise in elucidating mechanisms underlying these disorders and improving upon current diagnostic and treatment options. In this review, we address the current knowledge coinciding CHDs with immune and inflammatory associations, emphasizing conditions where this understanding would provide clinical benefit, and challenges in studying these mechanisms.

Cardiac Defects and Genetic Syndromes: Old Uncertainties and New Insights

Recent advances in understanding the genetic causes and anatomic subtypes of cardiac defects have revealed new links between genetic etiology, pathogenetic mechanisms and cardiac phenotypes. Although the same genetic background can result in different cardiac phenotypes, and similar phenotypes can be caused by different genetic causes, researchers’ effort to identify specific genotype–phenotype correlations remains crucial. In this review, we report on recent advances in the cardiac pathogenesis of three genetic diseases: Down syndrome, del22q11.2 deletion syndrome and Ellis–Van Creveld syndrome. In these conditions, the frequent and specific association with congenital heart defects and the recent characterization of the underlying molecular events contributing to pathogenesis provide significant examples of genotype–phenotype correlations. Defining these correlations is expected to improve diagnosis and patient stratification, and it has relevant implications for patient management and potential therapeutic options.

Atrioventricular Septal Defects: Pathology, Imaging, and Treatment Options

PURPOSE OF REVIEW

Atrioventricular septal defects (AVSD) represent a broad spectrum of congenital anomalies from simple to the most complex heart defects including some distinct types. Clinical presentation and timing of intervention differ by morphological subset and functional anatomy. Herein, we review morphological variations and characteristics that determine appropriate intervention and provide insights into functional anatomy based on detailed three-dimensional (3D) assessment of AVSDs.

RECENT FINDINGS

The understanding of functional morphology of AVSDs has improved significantly with detailed 3D echocardiographic evaluation of the atrioventricular junction and valve morphology. As prenatal detection of AVSDs has increased significantly, it has become the most common fetal cardiac diagnosis enabling antenatal counseling and delivery planning. Advances in diagnosis and perioperative care have resulted in optimal outcomes. The diagnosis and management of AVSDs have improved over the years with enhanced understanding of anatomy and perioperative care resulting in optimal short and long-term outcomes.

Perioperative care of adults with Down syndrome: a narrative review

Because of enhanced life expectancy due to medical and surgical therapeutic advances, it is estimated that there are more adults than children living with Down syndrome (DS), or trisomy 21, in the United States. Therefore, DS can no longer be considered a syndrome limited to the pediatric population. These patients are presenting for surgery and anesthesia in adult care settings, where anesthesiologists will encounter these patients more frequently. As these patients age, their commonly associated co-morbidities not only progress, but they also develop other cardiac, respiratory, gastrointestinal, and neurologic conditions. The manifestations and consequences of chronic disease can present new challenges for the anesthesiologist and require expertise and judgement to minimize patient risk. The purpose of this narrative review is to describe the common pediatric co-morbidities associated with DS and discuss the age-acquired manifestations. Additionally, considerations for anesthetic care of the adult with DS will be presented, including the preoperative assessment, intraoperative management, and postoperative care.

Maternal iron deficiency perturbs embryonic cardiovascular development in mice

Congenital heart disease (CHD) is the most common class of human birth defects, with a prevalence of 0.9% of births. However, two-thirds of cases have an unknown cause, and many of these are thought to be caused by in utero exposure to environmental teratogens. Here we identify a potential teratogen causing CHD in mice: maternal iron deficiency (ID). We show that maternal ID in mice causes severe cardiovascular defects in the offspring. These defects likely arise from increased retinoic acid signalling in ID embryos. The defects can be prevented by iron administration in early pregnancy. It has also been proposed that teratogen exposure may potentiate the effects of genetic predisposition to CHD through gene-environment interaction. Here we show that maternal ID increases the severity of heart and craniofacial defects in a mouse model of Down syndrome. It will be important to understand if the effects of maternal ID seen here in mice may have clinical implications for women.

Prevalence of Common Disease Conditions in a Large Cohort of Individuals With Down Syndrome in the United States

Purpose

Given the current life expectancy and number of individuals living with Down syndrome (DS), it is important to learn common occurrences of disease conditions across the developmental lifespan. This study analyzed data from a large cohort of individuals with DS in an effort to better understand these disease conditions, inform future screening practices, tailor medical care guidelines, and improve utilization of health care resources.

Methods

This retrospective, descriptive study incorporated up to 28 years of data, compiled from 6078 individuals with DS and 30,326 controls matched on age and sex. Data were abstracted from electronic medical records within a large Midwestern health system.

Results

In general, individuals with DS experienced higher prevalence of testicular cancer, leukemias, moyamoya disease, mental health conditions, bronchitis and pneumonia, gastrointestinal conditions, thyroid disorder, neurological conditions, atlantoaxial subluxation, osteoporosis, dysphagia, diseases of the eyes/adnexa and of the ears/mastoid process, and sleep apnea, relative to matched controls. Individuals with DS experienced lower prevalence of solid tumors, heart disease conditions, sexually transmitted diseases, HIV, influenza, sinusitis, urinary tract infections, and diabetes. Similar rates of prevalence were seen for lymphomas, skin melanomas, stroke, acute myocardial infarction, hepatitis, cellulitis, and osteoarthritis.

Conclusions

While it is challenging to draw a widespread conclusion about comorbidities in individuals with Down syndrome, it is safe to conclude that care for individuals with DS should not automatically mirror screening, prevention, or treatment guidelines for the general U.S. population. Rather, care for those with DS should reflect the unique needs and common comorbidities of this population.

Opportunities, barriers, and recommendations in down syndrome research

BACKGROUND

Recent advances in medical care have increased life expectancy and improved the quality of life for people with Down syndrome (DS). These advances are the result of both pre-clinical and clinical research but much about DS is still poorly understood. In 2020, the NIH announced their plan to update their DS research plan and requested input from the scientific and advocacy community.

OBJECTIVE

The National Down Syndrome Society (NDSS) and the LuMind IDSC Foundation worked together with scientific and medical experts to develop recommendations for the NIH research plan.

METHODS

NDSS and LuMind IDSC assembled over 50 experts across multiple disciplines and organized them in eleven working groups focused on specific issues for people with DS.

RESULTS

This review article summarizes the research gaps and recommendations that have the potential to improve the health and quality of life for people with DS within the next decade.

CONCLUSIONS

This review highlights many of the scientific gaps that exist in DS research. Based on these gaps, a multidisciplinary group of DS experts has made recommendations to advance DS research. This paper may also aid policymakers and the DS community to build a comprehensive national DS research strategy.

Post-infectious inflammatory syndrome associated with SARS-CoV-2 in a paediatric patient with Down syndrome

Neurological complications of SARS-CoV-2 continue to be recognised. In children, neurological phenomenon has been reported generally in the acute infectious period. It is possible that SARS-CoV-2 could trigger an immune-mediated post-infectious phenomenon. Here, we present a unique case of post-infectious marantic cardiac lesion causing cerebrovascular accident in a patient with Down syndrome.

Trends in the prenatal diagnosis of trisomy 21 show younger maternal age and shift in the distribution of congenital heart disease over a 20-year period

Prenatal testing has changed greatly over the past two decades, which may affect the diagnosis of congenital heart disease (CHD) in Down syndrome. The present study aimed to analyze changes in the prevalence and distribution of CHD diagnosed via ultrasonography and fetopathology in 462 fetuses with trisomy 21 between two consecutive 10-year periods (1999-2018), as well as the associations between CHDs, ultrasound markers, and extracardiac malformations. Overall, the frequency of cardiovascular malformations in trisomy 21 was 27.7 and 26.5%, and ultrasound identified 70 and 62% of CHDs during these periods. A profound increase in first-trimester ultrasound findings and associated anomalies with CHDs (ventricular septal defect, Tetralogy of Fallot) since 2009 were observed. Second-trimester nonstructural heart abnormalities were associated with ultrasound anomalies (74%) and major extracardiac malformations (42.9%). During both study periods, mothers carrying fetuses with CHD were significantly younger than those without CHD (p = 0.038, p = 0.009, respectively). Comparing the two 10-year periods, there were no changes in the prevalence and detection of CHDs. Trend analysis revealed that, although the frequency of CHD remained stable, the diagnostic spectrum had shifted between the study periods. Detection of nonstructural heart abnormalities necessitates detailed follow-up for cardiac/extracardiac malformations and chromosomal disorders.

Cardiac disease in Down Syndrome: literature review and international expert consensus in collaboration with Down Syndrome International (DSi)

Background

Congenital heart disease is common in patients with Down syndrome, yet clinical recommendations relating to its diagnosis and management in this patient group are lacking.

Main body

We discuss the ongoing collaboration between an international panel of cardiovascular experts and expert stakeholders from Down Syndrome International, an international disabled people's organisation with membership of organisations and individuals from 136 countries worldwide. The aim of this collaboration is to describe best clinical practice, focusing on 10 key areas relating to Down syndrome and cardiac disease, from prenatal diagnosis to the care of patients in areas of differing resource availability.

Conclusions

The planned expert consensus statement on cardiac disease in people with Down syndrome aims to foster communication between experts, direct future research and inform future practice guidelines for the diagnosis and management of cardiovascular disease in people with Down syndrome.

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.

Changes in ET-1, Plasma Neuropeptide Y, and CGRP in Child Patients With Congenital Heart Disease Complicated With Pulmonary Hypertension Before and After Operation

This study aims to explore the changes in endothelin-1 (ET-1), plasma neuropeptide Y, and calcitonin gene-related peptide (CGRP) in child patients before and after operation. A total of 80 child patients with congenital heart disease (CHD) complicated with pulmonary hypertension (PH) were enrolled and divided into control group (n = 40, conservative treatment for various reasons) and observation group (n = 40, active preoperative preparation and timely operative intervention) according to different treatments. There were positive correlations between systolic pulmonary arterial pressure (sPAP) and ET-1, plasma neuropeptide Y, while negative correlation between sPAP and CGRP. In conclusion, our data demonstrate that the levels of ET-1, plasma neuropeptide Y, and CGRP in PH-CHD were significantly changed after interventions, which provides new leads as alternative biomarkers to assess the efficacy of treatments against PH-CHD.

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.

Mortality Among Children with Down syndrome in Hong Kong: A Population-Based Cohort Study from Birth

OBJECTIVES

To describe the mortality patterns, comorbidities, and attendance at accident and emergency departments among children with Down syndrome in Hong Kong.

STUDY DESIGN

This is a population-based, retrospective cohort study of live births of children with Down syndrome delivered between 1995 and 2014, as identified from territory-wide hospitalization data in Hong Kong. The Kaplan-Meier product limit method was adopted to estimate the survival probabilities of children with Down syndrome by selected demographic and clinical characteristics. Cox regression analyses were conducted to examine associations of comorbidities and accident and emergency department accident and emergency departments attendances with mortality patterns.

RESULTS

There were 1010 live births of children with Down syndrome in Hong Kong within the study period and the average rate of live births with Down syndrome was 8.0 per 10 000 live births (95% CI, 6.8-9.30). The rate of live births with Down syndrome over the past 2 decades decreased from 11.8 per 10 000 live births in 1995 to 3.4 per 10 000 in 2014. Eighty-three patients with Down syndrome died during this period. The overall 6-month and 1- and 5-year survival probabilities were 95.8%, 94.4%, and 92.6%, respectively. There was a significant decrease in mortality rates over the study period, particularly among those born between 2000-2004 and 2005-2009 compared with those born between 1995 and 1999 (P < .05). Patients with Down syndrome without congenital cardiovascular anomalies and without low birth weight had lower mortality rates than those with these diagnoses.

CONCLUSIONS

Over the past 2 decades, the early life mortality of children with Down syndrome in Hong Kong has improved significantly along with a reduction in Down syndrome live births.

Suckling, Feeding, and Swallowing: Behaviors, Circuits, and Targets for Neurodevelopmental Pathology

All mammals must suckle and swallow at birth, and subsequently chew and swallow solid foods, for optimal growth and health. These initially innate behaviors depend critically upon coordinated development of the mouth, tongue, pharynx, and larynx as well as the cranial nerves that control these structures. Disrupted suckling, feeding, and swallowing from birth onward-perinatal dysphagia-is often associated with several neurodevelopmental disorders that subsequently alter complex behaviors. Apparently, a broad range of neurodevelopmental pathologic mechanisms also target oropharyngeal and cranial nerve differentiation. These aberrant mechanisms, including altered patterning, progenitor specification, and neurite growth, prefigure dysphagia and may then compromise circuits for additional behavioral capacities. Thus, perinatal dysphagia may be an early indicator of disrupted genetic and developmental programs that compromise neural circuits and yield a broad range of behavioral deficits in neurodevelopmental disorders.

Congenital heart defects associated with aneuploidy syndromes: New insights into familiar associations

The frequent occurrence of congenital heart defects (CHDs) in chromosome abnormality syndromes is well-known, and among aneuploidy syndromes, distinctive patterns have been delineated. We update the type and frequency of CHDs in the aneuploidy syndromes involving trisomy 13, 18, 21, and 22, and in several sex chromosome abnormalities (Turner syndrome, trisomy X, Klinefelter syndrome, 47,XYY, and 48,XXYY). We also discuss the impact of noninvasive prenatal screening (mainly, cell-free DNA analysis), critical CHD screening, and the growth of parental advocacy on their surgical management and natural history. We encourage clinicians to view the cardiac diagnosis as a "phenotype" which supplements the external dysmorphology examination. When detected prenatally, severe CHDs may influence decision-making, and postnatally, they are often the major determinants of survival. This review should be useful to geneticists, cardiologists, neonatologists, perinatal specialists, other pediatric specialists, and general pediatricians. As patients survive (and thrive) into adulthood, internists and related adult specialists will also need to be informed about their natural history and management.

Epigenome-wide base-resolution profiling of DNA methylation in chorionic villi of fetuses with Down syndrome by methyl-capture sequencing

BACKGROUND

Epigenetic mechanisms provide an interface between environmental factors and the genome and are influential in various diseases. These mechanisms, including DNA methylation, influence the regulation of development, differentiation, and establishment of cellular identity. Here, we performed high-throughput methylome profiling to determine whether differential patterns of DNA methylation correlate with Down syndrome (DS).

MATERIALS AND METHODS

We extracted DNA from the chorionic villi cells of five normal and five DS fetuses at the early developmental stage (12-13 weeks of gestation). Methyl-capture sequencing (MC-Seq) was used to investigate the methylation levels of CpG sites distributed across the whole genome to identify differentially methylated CpG sites (DMCs) and regions (DMRs) in DS. New functional annotations of DMR genes using bioinformatics tools were predicted.

RESULTS

DNA hypermethylation was observed in DS fetal chorionic villi cells. Significant differences were evident for 4,439 DMCs, including hypermethylation (n = 4,261) and hypomethylation (n = 178). Among them, 140 hypermethylated DMRs and only 1 hypomethylated DMR were located on 121 genes and 1 gene, respectively. One hundred twenty-two genes, including 141 DMRs, were associated with heart morphogenesis and development of the ear, thyroid gland, and nervous systems. The genes were significantly associated with DS and various diseases, including hepatopulmonary syndrome, conductive hearing loss, holoprosencephaly, heart diseases, glaucoma, and musculoskeletal abnormalities.

CONCLUSIONS

This is the first study to compare the whole-epigenome DNA methylation pattern of the chorionic villi cells from normal and DS fetuses at the early developmental-stage using MC-seq. Overall, our results indicate that the chorionic villi cells of DS fetuses are hypermethylated in all autosomes and suggested that altered DNA methylation may be a recurrent and functionally relevant downstream response to DS in human cells. This study provides basic information for future research focused on the pathophysiology of the DS and its potential effects, as well as the role DNA methylation plays in the early developmental stage of DS fetuses.

Persistent Hypoxemia in a Teen With Down Syndrome

Upchurch A, Sharma S, Hadigal S, Wagner M, Berry R. Persistent hypoxemia in a teen with down syndrome. J Clin Sleep Med. 2019;15(10):1547–1549.

Heart rate and blood pressure in male Ts65Dn mice: a model to investigate cardiovascular responses in Down syndrome

Down syndrome (Ds) is the most common chromosomal cause of intellectual disability that results from triplication of chromosome 21 genes. Lower blood pressure (BP) and heart rate (HR) in response to exercise and other stressors are prevalent in Ds, and are mediated by autonomic dysfunction. The Ts65Dn mouse is a model of Ds that is commonly used in preclinical studies, but has not been formally investigated for cardiovascular responses in conscious mice. Based on human studies of Ds, we hypothesized Ts65Dn would have lower BP and HR, but similar arterial stiffness. BP was quantified in conscious wild-type (WT) and Ts65Dn. A main effect for strain was observed for all BP measures (systolic, diastolic, mean, pulse pressure), with WT higher than Ts65Dn. Pulse wave velocity was similar between WT and Ts65Dn. High-frequency power spectra was higher in WT suggesting autonomic differences between strains. Freely moving HR was higher in WT versus Ts65Dn in both the dark and light cycles, although a main effect of circadian cycle was also present (dark> light). Similar to what is observed in humans, Ts65Dn has a lower BP which may be attributed to autonomic differences and result in preservation of arterial function with advancing age. Ts65Dn thus appears to capture the Ds cardiovascular phenotype across the lifespan. These data support further use of Ts65Dn to investigate mechanisms that may lead to altered BP and HR responses in Ds.

In Utero Diagnoses of Strikingly Similar Presentations of Complete Atrioventricular Septal Defects in a Pair of Dizygotic Twins Concordant for Trisomy 21

Trisomy 21, or Down syndrome (DS), is a genetic disorder affecting approximately 1 in 500–750 live births. The prevalence of DS has increased over the past two decades, correlating with a rise in the proportion of pregnancies complicated by advanced maternal age. There is also a correlation between advanced maternal age and dizygotic twinning rates. There is an increased risk of at least one twin being affected in dizygotic pregnancies compared to singletons. However, despite this greater relative risk, reports of concordance of DS in both dizygotic twins are very rare. Congenital heart disease (CHD) occurs in roughly 40% of individuals with DS, but there can be considerable phenotypic variation. The most common, atrioventricular septal defect accounts for only 40% of CHD seen in DS. There is also a higher incidence of CHD in twins, but also with a low incidence of concordance. There have been only five reported cases of concordant DS in dizygotic twins with confirmed chromosomal analyses; none of which describe concordant congenital heart disease. Here, we describe an unusual case of dizygotic twins of differing genders concordant for both Down syndrome and congenital heart disease of a strikingly similar presentation.