Supravalvular aortic stenosis: elastin arteriopathy

Supravalvular aortic stenosis - Novel pathogenic ELN variant in siblings with a wide spectrum of clinical cardiovascular features and a long follow-up from infancy to adulthood

BACKGROUND

Supravalvular aortic stenosis (SVAS) is an autosomal dominantly inherited congenital cardiovascular disease caused by disruption of elastin gene (ELN), encoding elastin, an essential component of elastic arteries. It usually affects the middle layer of the wall of the aorta but also the pulmonary and coronary arteries may be affected.

METHODS

We report a family with six affected siblings who were closely followed up from infancy to early adulthood at a pediatric cardiology outpatient clinic. Whole-exome sequencing was performed using DNA of the index patient. Targeted variant testing was performed for other family members.

RESULTS

The affected siblings presented with a wide spectrum of clinical features of SVAS, ranging from mild pulmonary artery stenosis with or without pulmonary artery branch stenoses to severe supravalvular aortic obstruction and coronary artery stenosis with fatal outcome. Genetic analysis identified a novel pathogenic 1-bp deletion c.1983delG, p. (Pro662Leufs*13) in the ELN gene. Males tended to have a more severe cardiac disease than females. However, if interventions were successful during infancy or early childhood, the outcome was fairly favorable. Moreover, supravalvular pulmonary stenosis, even when combined with a stenotic pulmonary valve and severe pulmonary artery branch stenoses, tended to resolve during follow-up.

CONCLUSIONS

We describe a family with six siblings showing elastin arteriopathy with variable disease severity and outcome. A novel pathogenic ELN gene variant was detected in five of them, indicating that there are obviously yet unknown genetic and environmental modifying factors that affect the severity and outcome in individual patients.

Cardiovascular Disease May Be Triggered by Gut Microbiota, Microbial Metabolites, Gut Wall Reactions, and Inflammation

Cardiovascular disease (CVD) may be inherited, as recently shown with the identification of single nucleotide polymorphisms (SNPs or "snips") on a 250 kb DNA fragment that encodes 92 proteins associated with CVD. CVD is also triggered by microbial dysbiosis, microbial metabolites, metabolic disorders, and inflammatory intestinal epithelial cells (IECs). The epithelial cellular adhesion molecule (Ep-CAM) and trefoil factor 3 (TFF3) peptide keeps the gut wall intact and healthy. Variations in Ep-CAM levels are directly linked to changes in the gut microbiome. Leptin, plasminogen activator inhibitor 1 (PAI1), and alpha-1 acid glycoprotein 1 (AGP1) are associated with obesity and may be used as biomarkers. Although contactin 1 (CNTN1) is also associated with obesity and adiposity, it regulates the bacterial metabolism of tryptophan (Trp) and thus appetite. A decrease in CNTN1 may serve as an early warning of CVD. Short-chain fatty acids (SCFAs) produced by gut microbiota inhibit pro-inflammatory cytokines and damage vascular integrity. Trimethylamine N-oxide (TMAO), produced by gut microbiota, activates inflammatory Nod-like receptors (NLRs) such as Nod-like receptor protein 3 (NLRP3), which increase platelet formation. Mutations in the elastin gene (ELN) cause supra valvular aortic stenosis (SVAS), defined as the thickening of the arterial wall. Many of the genes expressed by human cells are regulated by gut microbiota. The identification of new molecular markers is crucial for the prevention of CVD and the development of new therapeutic strategies. This review summarizes the causes of CVD and identifies possible CVD markers.

Concealed Truths Always Hide behind the Shadows of the Not So Obvious: Deadly Chest Pain Presentation

Acute aortic dissection (AAD) is a critical condition characterized by the tearing of the aortic wall, posing significant diagnostic challenges due to its diverse clinical presentations. We present the case of a 61-year-old male with hypertension and dyslipidemia who presented with acute abdominal and chest pain, initially raising suspicion of myocardial infarction. Despite an unremarkable electrocardiogram and initially normal troponin levels, the patient experienced ventricular fibrillation, prompting further evaluation. The patient's clinical course was complicated by recurrent cardiac arrests. Subsequent imaging revealed AAD, which was not initially recognized, emphasizing the importance of maintaining a broad differential diagnosis and the critical need for prompt recognition and management of AAD. This case underscores the necessity of considering AAD in patients with atypical presentations and the pivotal role of advanced imaging techniques in facilitating timely diagnosis and appropriate intervention.

Fetal Diagnosis of Supravalvular Aortic Stenosis and Pulmonary Stenosis in a Family with Non-Syndromic Elastin Mutation

Supravalvular aortic stenosis (SVAS) has been well described in Williams-Beuren Syndrome and non-syndromic elastin (ELN) mutations. Non-syndromic ELN mutations are inherited in an autosomal dominant pattern with incomplete penetrance and variable expressivity. ELN haploinsufficiency leads to progressive arteriopathy, typically affecting the aortic sinotubular junction. Multi-level pulmonary stenosis has also been reported and biventricular obstruction may portend a worse prognosis. Fetal presentation of ELN mutation with SVAS has not been previously reported in the literature. We present a case of fetal diagnosis of SVAS and multi-level pulmonary stenosis in a family with a known pathogenic ELN mutation (Exon 6, c.278del [p.Pro93Leufs*29]). On the fetus' initial fetal echo, there was only mild flow acceleration through the aortic outflow tract, however, she went on to develop progressive bilateral obstruction. In the early post-natal period, the child was clinically asymptomatic and showed similar mild SVAS and mild valvar and supravalvular pulmonary stenosis. Our case highlights the need for serial monitoring of fetuses with suspected or confirmed ELN arteriopathy.

Long-term Outcomes After Surgical Intervention for Congenital Supravalvar Aortic Stenosis in Children

BACKGROUND

Primary supravalvar aortic stenosis (SVAS) is a rare congenital cardiovascular condition that can coexist with Williams-Beuren syndrome, coronary artery involvement, aortic coarctation, and pulmonary artery stenosis. SVAS repair can be achieved with low perioperative mortality, but long-term survival remains less well understood. We used the Pediatric Cardiac Care Consortium, a multicenter United States-based registry for pediatric cardiac operations, to assess long-term outcomes after SVAS repair.

METHODS

We used Kaplan-Meier plots and Cox proportional hazards regression to examine factors associated with postdischarge deaths. These included sex, age-group, weight z-score, coexisting conditions (Williams-Beuren syndrome, coronary artery involvement, coarctation, and pulmonary artery stenosis), surgical techniques, and era, defined as early (1982-1995) or late (1996-2003). Survival was assessed by matching with the National Death Index through 2021.

RESULTS

Of 333 patients who met inclusion criteria, 313 (94.0%) survived to discharge and 188 (60.1%) had identifiers for National Death Index matching. Over a median follow-up of 25.2 years (interquartile range, 21.1-29.4 years), 17 deaths occurred. The 30-year survival after discharge from SVAS repair was 88.7% (95% CI, 82.9%-94.8%). Infantile surgery and non-Williams-Beuren syndrome were associated with decreased 30-year survival. From the various repairs, the 2-sinus technique had better outcomes compared with all other types, except the 3-sinus technique (nonsignificant difference). Adjusted analysis revealed infantile age and type of repair as associated with postdischarge probability of death.

CONCLUSIONS

These data demonstrate favorable long-term outcomes after SVAS repair, except for the infantile group that was associated with more diffuse arteriopathy. As techniques continue to evolve, future studies are warranted to investigate their long-term outcomes.

Genetic Testing for Supravalvar Aortic Stenosis: What to Do When It Is Not Williams Syndrome

BACKGROUND

We aimed to describe the frequency and yield of genetic testing in supravalvar aortic stenosis (SVAS) following negative evaluation for Williams-Beuren syndrome (WS).

METHODS AND RESULTS

This retrospective cohort study included patients with SVAS at our institution who had a negative evaluation for WS from May 1991 to September 2021. SVAS was defined as (1) peak supravalvar velocity of ≥2 meters/second, (2) sinotubular junction or ascending aortic Z score <-2.0, or (3) sinotubular junction Z score <-1.5 with family history of SVAS. Patients with complex congenital heart disease, aortic valve disease as the primary condition, or only postoperative SVAS were excluded. Genetic testing and diagnoses were reported. Of 162 patients who were WS negative meeting inclusion criteria, 61 had genetic testing results available (38%). Chromosomal microarray had been performed in 44 of 61 and was nondiagnostic for non-WS causes of SVAS. Sequencing of 1 or more genes was performed in 47 of 61. Of these, 39 of 47 underwent ELN sequencing, 20 of 39 (51%) of whom had a diagnostic variant. Other diagnoses made by gene sequencing were Noonan syndrome (3 PTPN11, 1 RIT1), Alagille syndrome (3 JAG1), neurofibromatosis (1 NF1), and homozygous familial hypercholesterolemia (1 LDLR1). Overall, sequencing was diagnostic in 29 of 47 (62%).

CONCLUSIONS

When WS is excluded, gene sequencing for SVAS is high yield, with the highest yield for the ELN gene. Therefore, we recommend gene sequencing using a multigene panel or exome analysis. Hypercholesterolemia can also be considered in individuals bearing the stigmata of this disease.

Patch aortoplasty for supravalvular aortic stenosis in an adult patient: A case report

INTRODUCTION

Supravalvular aortic stenosis (SVAS) is an uncommon congenital abnormality that presents with intimal thickening of the aortic media at the sinotubular junction. Given the congenital nature of the disease, patients usually become symptomatic in childhood.

PRESENTATION OF CASE

A 48-year-old man developed symptomatic SVAS in middle age. A patch aortoplasty with a bovine pericardial patch was performed. His postoperative course was uneventful, and echocardiography revealed a significant decrease in peak velocity and pressure gradient.

DISCUSSION

SVAS, a congenital heart disease with an incidence of 1 in 20,000 live births, is often linked to Williams syndrome but can also occur independently. Isolated SVAS is generally less severe and may not show symptoms in childhood. Its narrowing often stabilizes after growth, but in this middle-aged patient, symptoms appeared later in life. SVAS usually presents as discrete thickening above the sinuses of Valsalva or as diffuse narrowing along the ascending aorta. Surgical relief is the common treatment, with flap plasty using various patch techniques. This patient, having discrete stenosis and intact aortic valve function, underwent single-patch expansion. Key to this surgery is avoiding coronary artery stenosis, by considering coronary orifice location and other cardiac anomalies. A bovine pericardial patch was chosen for its bleeding control benefits.

CONCLUSION

Although SVAS progression in middle age is quite rare, it can be successfully corrected with detailed and selected surgical procedures.

Electrocardiograms Do Not Detect Myocardial Ischemia in Patients With Williams Syndrome and Nonsyndromic Elastin Arteriopathy With Coronary Artery Stenosis

Coronary artery stenosis (CAS) may affect up to 27% of patients with Williams syndrome (WS), which may lead to myocardial ischemia. Patients with WS face a 25- to 100-fold greater risk of sudden cardiac death, frequently linked to anesthesia. Assessing CAS requires either imaging while under general anesthesia or intraoperative assessment, with the latter considered the gold standard. Our study aimed to identify electrocardiogram (ECG) markers of myocardial ischemia in patients with WS or nonsyndromic elastin arteriopathy and documented CAS. We retrospectively reviewed patients with WS/elastin arteriopathy who underwent supravalvar aortic stenosis surgery and CAS assessment from January 1, 2006 to April 30, 2021. A pediatric electrophysiologist, not aware of the patients' CAS status, reviewed their preoperative ECGs for markers of ischemia. We assessed associations of study parameters using Wilcoxon rank-sum and Fisher's exact tests. Of 34 patients, 62% were male, with a median age of 20 months (interquartile range: 8 to 34). CAS was present in 62% (21 of 34), 76% of whom (16 of 21) were male. There were no ECG indicators of myocardial ischemia in patients with CAS. In conclusion, CAS was present in >1/2 the children with WS/elastin arteriopathy who underwent repair of supravalvar aortic stenosis. CAS in WS/nonsyndromic elastin arteriopathy does not appear to exhibit typical ECG-detectable myocardial ischemia. ECGs are not a useful screening tool for CAS in WS/elastin arteriopathy. Given the high anesthesia-related cardiac arrest risk, other noninvasive indicators of CAS are needed.

Long-term surgical outcomes of congenital supravalvular aortic stenosis: a systematic review, meta-analysis and microsimulation study

OBJECTIVES

Congenital supravalvular aortic stenosis (SVAS) is a rare form of congenital outflow tract obstruction and long-term outcomes are scarcely reported. This study aims to provide an overview of outcomes after surgical repair for congenital SVAS.

METHODS

A systematic review of published literature was conducted, including observational studies reporting long-term clinical outcome (>2 years) after SVAS repair in children or adults considering >20 patients. Early risks, late event rates and time-to-event data were pooled and entered into a microsimulation model to estimate 30-year outcomes. Life expectancy was compared to the age-, sex- and origin-matched general population.

RESULTS

Twenty-three publications were included, encompassing a total of 1472 patients (13 125 patient-years; pooled mean follow-up: 9.0 (6.2) years; median follow-up: 6.3 years). Pooled mean age at surgical repair was 4.7 (5.8) years and the most commonly used surgical technique was the single-patch repair (43.6%). Pooled early mortality was 4.2% (95% confidence interval: 3.2-5.5%) and late mortality was 0.61% (95% CI: 0.45-0.83) per patient-year. Based on microsimulation, over a 30-year time horizon, it was estimated that an average patient with SVAS repair (mean age: 4.7 years) had an observed life expectancy that was 90.7% (95% credible interval: 90.0-91.6%) of expected life expectancy in the matched general population. The microsimulation-based 30-year risk of myocardial infarction was 8.1% (95% credible interval: 7.3-9.9%) and reintervention 31.3% (95% credible interval: 29.6-33.4%), of which 27.2% (95% credible interval: 25.8-29.1) due to repair dysfunction.

CONCLUSIONS

After surgical repair for SVAS, 30-year survival is lower than the matched-general-population survival and the lifetime risk of reintervention is considerable. Therefore, lifelong monitoring of the cardiovascular system and in particular residual stenosis and coronary obstruction is recommended.

Human Genetics of Semilunar Valve and Aortic Arch Anomalies

Lesions of the semilunar valve and the aortic arch can occur either in isolation or as part of well-described clinical syndromes. The polygenic cause of calcific aortic valve disease will be discussed including the key role of NOTCH1 mutations. In addition, the complex trait of bicuspid aortic valve disease will be outlined, both in sporadic/familial cases and in the context of associated syndromes, such as Alagille, Williams, and Kabuki syndromes. Aortic arch abnormalities particularly coarctation of the aorta and interrupted aortic arch, including their association with syndromes such as Turner and 22q11 deletion, respectively, are also discussed. Finally, the genetic basis of congenital pulmonary valve stenosis is summarized, with particular note to Ras-/mitogen-activated protein kinase (Ras/MAPK) pathway syndromes and other less common associations, such as Holt-Oram syndrome.

Perioperative and Anesthetic Considerations in Pediatric Valvar and Subvalvar Aortic Stenosis

Aortic stenosis (AS) is a common form of left ventricular outflow tract obstruction (LVOTO) in children with congenital heart disease. This review specifically considers the perioperative features of valvar (VAS) and subvalvar AS (subAS) in the pediatric patient. Although VAS and subAS share some clinical features and diagnostic approaches, they are distinct clinical entities with separate therapeutic options, which range from transcatheter intervention to surgical repair. We detail the pathophysiology of AS and highlight the range of treatment strategies with a focus on anesthetic considerations for the care of these patients before, during, and after intervention.

Novel mutation in ELN gene causes cardiac abnormalities and inguinal hernia: case report

BACKGROUND

Elastin-driven genetic diseases are a group of complex diseases driven by elastin protein insufficiency and dominant-negative production of aberrant protein, including supravalvular aortic stenosis (SVAS) and autosomal dominant cutis laxa. Here, a Chinese boy with a novel nonsense mutation in the ELN gene is reported.

CASE PRESENTATION

We report a 1-year-old boy who presented with exercise intolerance, weight growth restriction with age, a 1-year history of heart murmur, and inguinal hernia. Gene sequencing revealed a novel nonsense mutation in the ELN gene (c.757 C > T (p.Gln253Ter), NM_000501.4). Due to severe branch pulmonary artery stenosis, the reconstruction of the branch pulmonary artery with autologous pericardium was performed. The inguinal hernia repair was performed 3 months postoperatively. After six months of outpatient follow-up, the child recovered well, gained weight with age, and had no special clinical symptoms.

CONCLUSION

We identified a de novo nonsense mutation in the ELN gene leading to mild SVAS and severe branch pulmonary artery stenosis. A new phenotype of inguinal hernia was also needed to be considered for possible association with the ELN gene. Still, further confirmation will be necessary.

Echocardiographic Evaluation of Aortic Stenosis: A Comprehensive Review

Echocardiography represents the most important diagnostic tool in the evaluation of aortic stenosis. The echocardiographic assessment of its severity should always be performed through a standardized and stepwise approach in order to achieve a comprehensive evaluation. The latest technical innovations in the field of echocardiography have improved diagnostic accuracy, guaranteeing a better and more detailed evaluation of aortic valve anatomy. An early diagnosis is of utmost importance since it shortens treatment delays and improves patient outcomes. Echocardiography plays a key role also in the evaluation of all the structural changes related to aortic stenosis. Detailed evaluation of subtle and subclinical changes in left ventricle function has a prognostic significance: scientific efforts have been addressed to identify the most accurate global longitudinal strain cut-off value able to predict adverse outcomes. Moreover, in recent years the role of artificial intelligence is increasingly emerging as a promising tool able to assist cardiologists in aortic stenosis screening and diagnosis, especially by reducing the rate of aortic stenosis misdiagnosis.

Recent Methods for Modifying Mechanical Properties of Tissue-Engineered Scaffolds for Clinical Applications

The limited regenerative capacity of the human body, in conjunction with a shortage of healthy autologous tissue, has created an urgent need for alternative grafting materials. A potential solution is a tissue-engineered graft, a construct which supports and integrates with host tissue. One of the key challenges in fabricating a tissue-engineered graft is achieving mechanical compatibility with the graft site; a disparity in these properties can shape the behaviour of the surrounding native tissue, contributing to the likelihood of graft failure. The purpose of this review is to examine the means by which researchers have altered the mechanical properties of tissue-engineered constructs via hybrid material usage, multi-layer scaffold designs, and surface modifications. A subset of these studies which has investigated the function of their constructs in vivo is also presented, followed by an examination of various tissue-engineered designs which have been clinically translated.

A new mouse model of elastin haploinsufficiency highlights the importance of elastin to vascular development and blood pressure regulation

Supravalvular aortic stenosis (SVAS) is an autosomal dominant disease resulting from elastin (ELN) haploinsufficiency. Individuals with SVAS typically develop a thickened arterial media with an increased number of elastic lamellae and smooth muscle cell (SMC) layers and stenosis superior to the aortic valve. A mouse model of SVAS (Eln+/-) was generated that recapitulates many aspects of the human disease, including increased medial SMC layers and elastic lamellae, large artery stiffness, and hypertension. The vascular changes in these mice were thought to be responsible for the hypertension phenotype. However, a renin gene (Ren) duplication in the original 129/Sv genetic background and carried through numerous strain backcrosses raised the possibility of renin-mediated effects on blood pressure. To exclude excess renin activity as a disease modifier, we utilized the Cre-LoxP system to rederive Eln hemizygous mice on a pure C57BL/6 background (Sox2-Cre;Elnf/f). Here we show that Sox2-Cre;Eln+/f mice, with a single Ren1 gene and normal renin levels, phenocopy the original global knockout line. Characteristic traits include an increased number of elastic lamellae and SMC layers, stiff elastic arteries, and systolic hypertension with widened pulse pressure. Importantly, small resistance arteries of Sox2-Cre;Eln+/f mice exhibit a significant change in endothelial cell function and hypercontractility to angiotensin II, findings that point to pathway-specific alterations in resistance arteries that contribute to the hypertensive phenotype. These data confirm that the cardiovascular changes, particularly systolic hypertension, seen in Eln+/- mice are due to Eln hemizygosity rather than Ren duplication.

Sudden Cardiac Arrest During a Sedated Cardiac Magnetic Resonance Study in a Nonsyndromic Child with Evolving Supravalvar Aortic Stenosis Due to Familial ELN Mutation

Supravalvar aortic stenosis (SVAS) is a less common but clinically important form of left ventricular outflow tract obstruction, and commonly associated with Williams syndrome (WS). SVAS outside of WS may also occur sporadically or in a familial form, often with identifiable mutations in the elastin (ELN) gene. While risk of sudden cardiac death in patients with SVAS has been extensively described in the context of WS, less is known about risk in patients with isolated SVAS. We report a case of a nonsyndromic two-year-old boy with evolving manifestations of SVAS who developed sudden cardiac arrest and death during a sedated cardiac magnetic resonance imaging study. A strong family history of SVAS was present and targeted genetic testing identified an ELN gene mutation in the boy's affected father and other paternal relatives. We review risk factors found in the literature for SCA in SVAS patients and utilize this case to raise awareness of the risk of cardiac events in these individuals even in the absence of WS or severe disease. This case also underscores the importance of genetic testing, including targeted panels specifically looking for ELN gene mutations, in all patients with SVAS even in the absence of phenotypic concerns for WS or other genetic syndromes.

Role of cardiovascular magnetic resonance in the clinical evaluation of left ventricular hypertrophy: a 360° panorama

Left ventricular hypertrophy (LVH) is a frequent imaging finding in the general population. In order to identify the precise etiology, a comprehensive diagnostic approach should be adopted, including the prevalence of each entity that may cause LVH, family history, clinical, electrocardiographic and imaging findings. By providing a detailed evaluation of the myocardium, cardiovascular magnetic resonance (CMR) has assumed a central role in the differential diagnosis of left ventricular hypertrophy, with the technique of parametric imaging allowing more refined tissue characterization. This article aims to establish a parallel between pathophysiological features and imaging findings through the broad spectrum of LVH entities, emphasizing the role of CMR in the differential diagnosis.

High heritability of ascending aortic diameter and trans-ancestry prediction of thoracic aortic disease

Enlargement of the aorta is an important risk factor for aortic aneurysm and dissection, a leading cause of morbidity in the developed world. Here we performed automated extraction of ascending aortic diameter from cardiac magnetic resonance images of 36,021 individuals from the UK Biobank, followed by genome-wide association. We identified lead variants across 41 loci, including genes related to cardiovascular development (HAND2, TBX20) and Mendelian forms of thoracic aortic disease (ELN, FBN1). A polygenic score significantly predicted prevalent risk of thoracic aortic aneurysm and the need for surgical intervention for patients with thoracic aneurysm across multiple ancestries within the UK Biobank, FinnGen, the Penn Medicine Biobank and the Million Veterans Program (MVP). Additionally, we highlight the primary causal role of blood pressure in reducing aortic dilation using Mendelian randomization. Overall, our findings provide a roadmap for using genetic determinants of human anatomy to understand cardiovascular development while improving prediction of diseases of the thoracic aorta.

Elastin, arterial mechanics, and stenosis

Elastin is a long-lived extracellular matrix protein that is organized into elastic fibers that provide elasticity to the arterial wall, allowing stretch and recoil with each cardiac cycle. By forming lamellar units with smooth muscle cells, elastic fibers transduce tissue-level mechanics to cell-level changes through mechanobiological signaling. Altered amounts or assembly of elastic fibers leads to changes in arterial structure and mechanical behavior that compromise cardiovascular function. In particular, genetic mutations in the elastin gene (ELN) that reduce elastin protein levels are associated with focal arterial stenosis, or narrowing of the arterial lumen, such as that seen in supravalvular aortic stenosis and Williams-Beuren syndrome. Global reduction of Eln levels in mice allows investigation of the tissue- and cell-level arterial mechanical changes and associated alterations in smooth muscle cell phenotype that may contribute to stenosis formation. A loxP-floxed Eln allele in mice highlights cell type- and developmental origin-specific mechanobiological effects of reduced elastin amounts. Eln production is required in distinct cell types for elastic layer formation in different parts of the mouse vasculature. Eln deletion in smooth muscle cells from different developmental origins in the ascending aorta leads to characteristic patterns of vascular stenosis and neointima. Dissecting the mechanobiological signaling associated with local Eln depletion and subsequent smooth muscle cell response may help develop new therapeutic interventions for elastin-related diseases.

JAGGED1/NOTCH3 activation promotes aortic hypermuscularization and stenosis in elastin deficiency

Obstructive arterial diseases, including supravalvular aortic stenosis (SVAS), atherosclerosis, and restenosis, share 2 important features: an abnormal or disrupted elastic lamellae structure and excessive smooth muscle cells (SMCs). However, the relationship between these pathological features is poorly delineated. SVAS is caused by heterozygous loss-of-function, hypomorphic, or deletion mutations in the elastin gene (ELN), and SVAS patients and elastin-mutant mice display increased arterial wall cellularity and luminal obstructions. Pharmacological treatments for SVAS are lacking, as the underlying pathobiology is inadequately defined. Herein, using human aortic vascular cells, mouse models, and aortic samples and SMCs derived from induced pluripotent stem cells of ELN-deficient patients, we demonstrated that elastin insufficiency induced epigenetic changes, upregulating the NOTCH pathway in SMCs. Specifically, reduced elastin increased levels of γ-secretase, activated NOTCH3 intracellular domain, and downstream genes. Notch3 deletion or pharmacological inhibition of γ-secretase attenuated aortic hypermuscularization and stenosis in Eln-/- mutants. Eln-/- mice expressed higher levels of NOTCH ligand JAGGED1 (JAG1) in aortic SMCs and endothelial cells (ECs). Finally, Jag1 deletion in SMCs, but not ECs, mitigated the hypermuscular and stenotic phenotype in the aorta of Eln-/- mice. Our findings reveal that NOTCH3 pathway upregulation induced pathological aortic SMC accumulation during elastin insufficiency and provide potential therapeutic targets for SVAS.

NOTCH3 as a modulator of vascular disease: a target in elastin deficiency and arterial pathologies

During blood vessel disease, vascular smooth muscle cell (VSMC) expansion and interaction with the matrix trigger changes in gene expression and phenotype. In this issue of the JCI, Dave et al. discover a signaling network that drives VSMC expansion and vascular obstruction caused by elastin insufficiency. Using a combination of gene-targeted mice, tissues and cells from patients with Williams-Beuren syndrome, and targeting of elastin in human VSMCs, the authors identified VSMC-derived NOTCH3 signaling as a critical mediator of aortic hypermuscularization and loss of vascular patency. NOTCH3-specific therapies or therapies that target downstream molecular pathways may provide opportunities to minimize VSMC growth and treat cardiovascular disease with minimal side effects.

Passive biaxial mechanical behavior of newborn mouse aorta with and without elastin

Aortic wall material properties are needed for computational models and for comparisons across developmental and disease states. There has been abundant work in comparing aortic material properties across disease states, but limited work across developmental states. We performed passive biaxial mechanical testing on newborn mouse aorta with (Eln^+/+) and without (Eln^-/-) elastin. Elastin provides elasticity to the aortic wall and is necessary for survival beyond birth in the mouse. Mechanically functional elastin is challenging to create in vitro and so Eln^-/- aorta can be a comparison for tissue engineered arteries with limited elastin amounts. We found that a traditional arterial strain energy function provided reasonable fits to newborn mouse aorta and generally predicted lower material constants in Eln^-/- compared to Eln^+/+ aorta. At physiologic pressures, the circumferential stresses and moduli trended lower in Eln^-/- compared to Eln^+/+ aorta. Increased blood pressure in Eln^-/- mice helps to alleviate the differences in stresses and moduli. Increased blood pressure also serves to partially offload stresses in the isotropic compared to the anisotropic component of the wall. The baseline material parameters can be used in computational models of growth and remodeling to improve understanding of developmental mechanobiology and tissue engineering strategies.

Compendium of causative genes and their encoded proteins for common monogenic disorders

A compendium is presented of inherited monogenic disorders that have a prevalence of >1:20,000 in the human population, along with their causative genes and encoded proteins. "Simple" monogenic diseases are those for which the clinical features are caused by mutations impacting a single gene, usually in a manner that alters the sequence of the encoded protein. Of course, for a given "monogenic disorder", there is sometimes more than one potential disease gene, mutations in any one of which is sufficient to cause phenotypes of that disorder. Disease-causing mutations for monogenic disorders are usually passed on from generation to generation in a Mendelian fashion, and originate from spontaneous (de novo) germline founder mutations. In the past monogenic disorders have often been written off as targets for drug discovery because they sometimes are assumed to be rare disorders, for which the meager projected financial payoff of drug discovery and development has discouraged investment. However, not all monogenic diseases are rare. Here, we report that that currently available data identifies 72 disorders with a prevalence of at least 1 in 20,000 humans. For each, we tabulate the gene(s) for which mutations cause the spectrum of phenotypes associated with that disorder. We also identify the gene and protein that most commonly causes each disease. 34 of these disorders are caused exclusively by mutations in only a single gene and encoded protein.

Nationwide questionnaire data of 229 Williams-Beuren syndrome patients using WhatsApp tool

BACKGROUND

Williams-Beuren syndrome is a multisystemic disorder caused by a microdeletion of the 7q11.23 region. Although familial cases with autosomal dominant inheritance have been reported, the vast majority are sporadic.

OBJECTIVE

To investigate the main complaints and clinical findings of patients with Williams-Beuren syndrome.

METHODS

A total of 757 parents of patients registered in the Brazilian Association of Williams-Beuren Syndrome (ABSW) received a questionnaire via WhatsApp from March to July 2017.

RESULTS

In total, 229 parents answered the survey. Age of diagnosis ranged from 2 days to 34 years (median: 3 years). The main clinical findings reported by the parents were abdominal colic (83.3%), failure to thrive (71.5%), feeding difficulty in the first year (68.9%), otitis (56.6%), urinary tract infections (31.9%), precocious puberty (27.1%) and scoliosis (15.9%). Cardiac defects were present in 66% of patients, and the most frequent defect was supravalvular aortic stenosis (36%). Arterial hypertension was reported in 23%. Hypercalcemia was reported in 10.5% of patients, mainly during the first year of life. Hyperacusis and hypersociability were common complaints (both present in 89%). Other behavioral and neuropsychiatric symptoms reported by the parents included attention deficit (89%), anger crises (83%), excessive fear (66%), depression (64%), anxiety (67%) and hypersexuality (33%). The most common complaints were hypersensitivity to sounds, talkative personality, emotional dependence and learning difficulties. In 98.3%, the parents denied family history.

CONCLUSIONS

Williams-Beuren syndrome requires close follow-up with different medical specialties due to their variable clinical comorbidities, including language and school learning difficulties, behavioral and psychiatric problems.

Extracellular matrix-mediated remodeling and mechanotransduction in large vessels during development and disease

The vascular extracellular matrix (ECM) is synthesized and secreted during embryogenesis and facilitates the growth and remodeling of large vessels. Proper interactions between the ECM and vascular cells are pivotal for building the vasculature required for postnatal dynamic circulation. The ECM serves as a structural component by maintaining the integrity of the vessel wall while also regulating intercellular signaling, which involves cytokines and growth factors. The major ECM component in large vessels is elastic fibers, which include elastin and microfibrils. Elastin is predominantly synthesized by vascular smooth muscle cells (SMCs) and uses microfibrils as a scaffold to lay down and assemble cross-linked elastin. The absence of elastin causes developmental defects that result in the subendothelial proliferation of SMCs and inward remodeling of the vessel wall. Notably, elastic fiber formation is attenuated in the ductus arteriosus and umbilical arteries. These two vessels function during embryogenesis and close after birth via cellular proliferation, migration, and matrix accumulation. In dynamic postnatal mechano-environments, the elastic fibers in large vessels also serve an essential role in proper signal transduction as a component of elastin-contractile units. Disrupted mechanotransduction in SMCs leads to pathological conditions such as aortic aneurysms that exhibit outward remodeling. This review discusses the importance of the ECM-mainly the elastic fiber matrix-in large vessels during developmental remodeling and under pathological conditions. By dissecting the role of the ECM in large vessels, we aim to provide insights into the role of ECM-mediated signal transduction that can provide a basis for seeking new targets for intervention in vascular diseases.

Elastic tissue disruption is a major pathogenic factor to human vascular disease

Elastic fibers are essential components of the arterial extracellular matrix. They consist of the protein elastin and an array of microfibrils that support the protein and connect it to the surrounding matrix. The elastin gene encodes tropoelastin, a protein that requires extensive cross-linking to become elastin. Tropoelastin is expressed throughout human life, but its expression levels decrease with age, suggesting that the potential to synthesize elastin persists during lifetime although declines with aging. The initial abnormality documented in human atherosclerosis is fragmentation and loss of the elastic network in the medial layer of the arterial wall, suggesting an imbalance between elastic fiber injury and restoration. Damaged elastic structures are not adequately repaired by synthesis of new elastic elements. Progressive collagen accumulation follows medial elastic fiber disruption and fibrous plaques are formed, but advanced atherosclerosis lesions do not develop in the absence of prior elastic injury. Aging is associated with arterial extracellular matrix anomalies that evoke those present in early atherosclerosis. The reduction of elastic fibers with subsequent collagen accumulation leads to arterial stiffening and intima-media thickening, which are independent predictors of incident hypertension in prospective community-based studies. Arterial stiffening precedes the development of hypertension. The fundamental role of the vascular elastic network to arterial structure and function is emphasized by congenital disorders caused by mutations that disrupt normal elastic fiber production. Molecular changes in the genes coding tropoelastin, lysyl oxidase (tropoelastin cross-linking), and elastin-associated microfibrils, including fibrillin-1, fibulin-4, and fibulin-5 produce severe vascular injury due to absence of functional elastin.

Clinical and genetic characteristics of two cases with Williams-Beuren syndrome

Herein, we describe 2 cases of Williams-Beuren syndrome (WBS). In both cases, the patients exhibited mental retardation, characteristic facial features, and indirect inguinal hernia. Case 1, a girl aged 2 years and 5 months old, presented with hypercalcemia, and in case 2, a boy aged 4 years and 11 months old, the disorder manifested as infantile spasms, supravalvular aortic stenosis, and pulmonary stenosis. Brain MRI revealed no abnormalities in either case. The electroencephalogram of case 2 showed hypsarrhythmia. Case 1 was treated with bisphosphonates and somatropin for hypercalcemia and short stature. Case 2 received antiepileptic drug and ketogenic diet therapy. In both cases, a 7q11.23 deletion including fragment deletion of the GTF21 gene was found, which may be associated with mental retardation. Notably, in case 2, a 921.1kb deletion in Yq11.23 was detected, which has not been reported in WBS before. The deletion of Yq11.23 is located in the AZFc region, which is an important factor in male infertility with primary azoospermia and oligozoospermia. The occurrence of hypercalcemia in case 1 may be related to the deletion of BAZ1B, while the supravalvular aortic stenosis and pulmonary stenosis were associated with deletion of the ELN gene. We explored the clinical and genetic characteristics of WBS to better understand disease.

Supravalvular Aortic Stenosis and the Risk of Premature Death Among Patients With Homozygous Familial Hypercholesterolemia

Patients with homozygous familial hypercholesterolemia (HoFH) have a high risk for premature death. Supravalvular aortic stenosis (SVAS) is a common and the feature lesion of the aortic root in HoFH. The relation between SVAS and the risk of premature death in patients with HoFH has not been fully investigated. The present study analysis included 97 HoFH patients with mean age of 14.7 (years) from the Genetic and Imaging of Familial Hypercholesterolemia in Han Nationality Study. During the median (±SD) follow-up 4.0 (±4.0) years, 40 (41.2%) participants had SVAS and 17 (17.5%) participants experienced death. The proportion of premature death in the non-SVAS and SVAS group was 7.0% and 32.5%, respectively. Compared with the non-SVAS group, SVAS group cumulative survival was lower in the HoFH (log-rank test, p <0.001). This result was further confirmed in the multivariable Cox regression models. After adjusting for age, sex, low density lipoprotein cholesterol (LDL_C)-year-score, lipid-lowering drugs, cardiovascular disease, and carotid artery plaque, SVAS was an independent risk factor of premature death in HoFH on the multivariate analysis (hazard ratio 4.45; 95% confidence interval, 1.10 to 18.12; p = 0.037). In conclusion, a significantly increased risk of premature death was observed in HoFH patients with SVAS. Our study emphasized the importance of careful and aggressive management in these patients when appropriate.

Supravalvar aortic stenosis: Imaging characteristics and associations on multidetector computed tomography angiography

AIM

To evaluate the imaging features and associations in patients with supravalvar aortic stenosis on multidetector computed tomography (CT) angiography.

MATERIALS AND METHODS

We retrospectively reviewed all CT angiography studies performed for evaluation of congenital heart diseases at our institution through the period from January 2014 to June 2020. Cases with supravalvar aortic stenosis were identified and classified as syndromic and nonsyndromic based on history, physical examination, and relevant investigations. The type and extent of vascular involvement and associated cardiovascular abnormalities were characterized.

RESULTS

Supravalvar aortic stenosis was identified in 26/3926 (0.66%) patients (22 males and 4 females; Age range: 2 months to 20 years). Discrete stenosis was seen in 14/26 (53.8%) patients, while diffuse involvement of the ascending aorta to varying degrees was seen in the remaining 12 (46.2%) patients. About 15/26 (57.7%) patients had pulmonary involvement at some level, namely, infundibular, valvar, supravalvar, or peripheral pulmonic stenosis while 15/26 (57.7%) patients had coronary arterial involvement either in the form of stenosis, occlusion, or ectasia. Aortic valvular abnormality including thickening, partial fusion, and adhesion of leaflet edges to the sinutubular junction causing reduced coronary inflow was seen in 15/26 (57.7%) patients. Associated ventricular septal defect, patent ductus arteriosus, and mitral valvular prolapse were seen in four (15.4%), five (19.2%), and two (7.7%) patients respectively.

CONCLUSION

Supravalvar aortic stenosis is a rare abnormality showing associated pulmonary arterial involvement, coronary arterial involvement, aortic valvular abnormalities, and associated congenital cardiac defects in the majority of cases, which may influence surgical outcomes.

A Novel Splice-Site Mutation in the ELN Gene Suggests an Alternative Mechanism for Vascular Elastinopathies

The ELN gene encodes elastin, a fundamental protein of the extracellular matrix that confers elasticity to different tissues including blood vessels. The formation of elastin fibers is a complex process involving monomer coacervation and subsequent crosslinking. Mutations in exons 1-29 of the ELN gene have been linked to supravalvular aortic stenosis (SVAS) whereas mutations in exons 30-33 are associated with autosomal dominant cutis laxa (ADCL). This striking segregation has led to the hypothesis that distinct molecular mechanisms underlie both diseases. SVAS is believed to arise through haploinsufficiency while ADCL is hypothesized to be caused by a dominant negative effect. Here, we describe a patient with SVAS harboring a novel splice-site mutation in the last exon of ELN. The location of this mutation is not consistent with current knowledge of SVAS, since all mutations reported in the C-terminus have been found in ADCL patients, and a thorough evaluation did not reveal significant skin involvement in this case. RT-PCR analysis of skin tissue showed that C-terminal mutations in the region can lead to the production of aberrant transcripts through intron retention and activation of cryptic splice sites and suggest that disruption of the very last exon can lead to functional haploinsufficiency potentially related to SVAS.

Expression Quantitative Trait Locus Mapping in Pulmonary Arterial Hypertension

Expression quantitative trait loci (eQTL) can provide a link between disease susceptibility variants discovered by genetic association studies and biology. To date, eQTL mapping studies have been primarily conducted in healthy individuals from population-based cohorts. Genetic effects have been known to be context-specific and vary with changing environmental stimuli. We conducted a transcriptome- and genome-wide eQTL mapping study in a cohort of patients with idiopathic or heritable pulmonary arterial hypertension (PAH) using RNA sequencing (RNAseq) data from whole blood. We sought confirmation from three published population-based eQTL studies, including the GTEx Project, and followed up potentially novel eQTL not observed in the general population. In total, we identified 2314 eQTL of which 90% were cis-acting and 75% were confirmed by at least one of the published studies. While we observed a higher GWAS trait colocalization rate among confirmed eQTL, colocalisation rate of novel eQTL reported for lung-related phenotypes was twice as high as that of confirmed eQTL. Functional enrichment analysis of genes with novel eQTL in PAH highlighted immune-related processes, a suspected contributor to PAH. These potentially novel eQTL specific to or active in PAH could be useful in understanding genetic risk factors for other diseases that share common mechanisms with PAH.

Genetic Diagnosis and the Severity of Cardiovascular Phenotype in Patients With Elastin Arteriopathy

Supplemental Digital Content is available in the text.

Elastin insufficiency causes recurrent vascular stenoses. Hemizygous deletion of the elastin gene (ELN) causes Williams-Beuren syndrome (WBS), while single nucleotide variants in ELN cause nonsyndromic supravalvar aortic stenosis (SVAS). Our objective was to compare cardiovascular disease outcomes in patients with WBS and nonsyndromic SVAS.

Aortopulmonary fistula in a Warmblood mare associated with an aortic aneurysm and supravalvular aortic stenosis

This case report describes the clinical presentation, the necropsy findings, and genetic results of a 13-year-old Warmblood mare presented with colic and a bilaterally loud, holosystolic murmur. Echocardiographic examination revealed the presence of a thoracic aortic aneurysm, an aortic pseudoaneurysm, a periaortic hematoma (circumferential cuffing by perivascular hemorrhage), and aortopulmonary fistulation. A supravalvular aortic stenosis (SVAS) was visible during echocardiography. Necropsy confirmed that the thoracic aortic aneurysm had ruptured and connected to the pseudoaneurysm, which fistulated into the pulmonary artery. Histologically, the aneurysm wall revealed chronic lesions such as fibrosis, mucin depositions, mineralizations, and elastin fragmentation. The mid abdominal aorta showed lesions suggestive of a systemic elastin arteriopathy. Molecular analysis, however, could not attribute this disease to a variant in the elastin gene, the most common causative gene for SVAS. To the authors' knowledge, this case report describes a case of aortopulmonary fistulation in a Warmblood horse associated with the presence of SVAS and an aortic aneurysm.

Myhre Syndrome Associated With Dunbar Syndrome and Urinary Tract Abnormalities: A Case Report

Myhre syndrome is a rare condition caused by a mutation in the SMAD4 gene, which leads to a defective TGF-β/BMP signaling, resulting in the proliferation of abnormal fibrous tissues. Clinically, patients with Myhre syndrome manifest with defects of connective tissue (skin, muscles, joints), and cardiovascular and neurological impairment. In our report, we present a case of a 16-year-old female with skeletal abnormalities, reduced articular mobility, skin, and muscular hypertrophy and cardiovascular defects characteristic of Myhre syndrome. Long-term pulmonary hypertension and arterial hypertension were persistent in spite of antihypertensive treatment. Our patient was also diagnosed with chronic kidney disease and Dunbar syndrome, which is an external compression of the coeliac trunk or coeliac artery by the surrounding tissues. Until now, only a few cases of renal complications in Myhre syndrome have been published. We describe for the first time a female patient with genetically confirmed Myhre syndrome caused by the p.Ile500Val SMAD4 mutation presenting with an unusual occurrence of congenital vesicoureteral reflux, proteinuria with a decreased renal function, and a condition recognized as Dunbar syndrome.

Perioperative Echocardiography in the Adult With Congenital Heart Disease

Survival of patients with congenital heart disease has significantly improved over the last 2 decades, confronting interventionalists, surgeons, anesthesiologists, cardiologists, and intensivists with often unfamiliar complex pathophysiology in the perioperative setting. Aside from cardiac catheterization, echocardiography has become the main imaging modality in the hospitalized adult with congenital heart disease. The great variety of congenital lesions and their prior surgical management challenges practitioners to generate optimal imaging, reporting, and interpretation of these complex anatomic structures. Standardization of echocardiographic studies can not only provide significant benefits in the surveillance of these patients, but also facilitate understanding of pathophysiologic mechanism and assist clinical management in the perioperative setting. Knowledge in obtaining and interpreting uniform imaging protocols is essential for the perioperative clinician. In this publication, the authors review current international consensus recommendations on echocardiographic imaging of adults with congenital heart disease and describe the fundamental components by specific lesion. The authors will emphasize key aspects pertinent to the clinical management when imaging these patients in the perioperative setting. The goal of this review is to familiarize the perioperative physician on how to structure and standardize echocardiographic image acquisition of congenital heart disease anatomy for optimal clinical management.

Collagens and elastin genetic variations and their potential role in aging-related diseases and longevity in humans

Collagens and elastin are 'building blocks' of tissues and extracellular matrix. Mutations in these proteins cause severe congenital syndromes. Adverse genetic variations may accelerate the aging process in adults contributing to premature morbidity, disability and/or mortality. Favorable variants may contribute to longevity and/or healthy aging, but this is much less studied. We reviewed the association between variation in the genes of collagens and elastin and premature aging, accelerated aging, age-related diseases and/or frailty; and the association between genetic variation in those and longevity and/or healthy aging in humans. A systematic search was conducted in MEDLINE and other online databases (OMIM, Genetics Home Reference, Orphanet, ClinVar). Results suggest that genetic variants lead to aging phenotypes of known congenital disease, but also to association with common age-related diseases in adults without known congenital disease. This may be due to the variable penetrance and expressivity of many variants. Some collagen variants have been associated with longevity or healthy aging. A limitation is that most studies had <1000 participants and their criterion for statistical significance was p < 0.05. Results highlight the importance of adopting a lifecourse approach to the study of the genomics of aging. Gerontology can help with new methodologies that operationalize biological aging.

Supravalvular Aortic Stenosis Caused by a Familial Chromosome 7 Inversion Disrupting the ELN Gene Uncovered by Whole-Genome Sequencing

Apparently, balanced chromosomal rearrangements usually have no phenotypic consequences for the carrier. However, in some cases, they may be associated with an abnormal phenotype. We report herein the case of a 4-year-old boy presenting with clinically isolated supravalvular aortic stenosis (SVAS). No chromosomal imbalance was detected by array CGH. The karyotype showed a balanced paracentric chromosome 7 inversion. Breakpoint characterization using paired-end whole-genome sequencing (WGS) revealed an ELN gene disruption in intron 1, accounting for the phenotype. Family study showed that the inversion was inherited, with incomplete penetrance. To our knowledge, this is the first case of a disruption of the ELN gene characterized by WGS. It contributes to refine the genotype-phenotype correlation in ELN disruption. Although this disruption is a rare etiology of SVAS, it cannot be detected by the diagnostic tests usually performed, such as array CGH or sequencing methods (Sanger, panel, or exome sequencing). With the future perspective of WGS as a diagnostic tool, it will be important to include a structural variation analysis in order to detect balanced rearrangements and gene disruption.

Atrial septal defects, supravalvular aortic stenosis and syndromes predisposing to aneurysm of large vessels

Atrial septal defect is a persistent interatrial communication. It is the second most common congenital heart defect and is detected in 1:1500 live births. Clinical course is variable and depends on the size of the malformation. Clinical diagnosis is based on patient history, physical and instrumental examination. Atrial septal defect is frequently sporadic, but familial cases have been reported. The disease has autosomal dominant inheritance with reduced penetrance, variable expressivity and genetic heterogeneity. Supravalvular aortic stenosis is a congenital narrowing of the lumen of the ascending aorta. It has an incidence of 1:20000 newborns and a prevalence of 1:7500. Clinical diagnosis is based on patient history, physical and instrumental examination. Supravalvular aortic stenosis is either sporadic or familial and has autosomal dominant inheritance with reduced penetrance and variable expressivity. It is associated with mutations in the ELN gene. Syndromes predisposing to aneurysm of large vessels is a group of inherited disorders that may affect different segments of the aorta. They may occur in isolation or associated with other genetic syndromes. Clinical symptoms are highly variable. Familial thoracic aortic aneurysm and dissection accounts for ~20% of all cases of aneurysms. The exact prevalence is unknown. Clinical diagnosis is based on medical history, physical and instrumental examination. Genetic testing is useful for confirming diagnosis of these syndromes and for differential diagnosis, recurrence risk evaluation and prenatal diagnosis in families with a known mutation. Most syndromes predisposing to aneurysm of large vessels have autosomal dominant inheritance with reduced penetrance and variable expressivity. (www.actabiomedica.it)

Williams syndrome

Williams syndrome affects approximately one in 10 000 people and is caused by the deletion of genes on chromosome 7q11.23 which code for elastin. The phenotypic appearance of people with Williams syndrome is well characterized, but there continues to be new genetic and therapeutic discoveries. Patients with Williams syndrome have increased morbidity and mortality under sedation and anesthesia, largely as a result of cardiovascular abnormalities. This review article focuses on new information about Williams syndrome and outlines a structured approach to patients with Williams syndrome in the perioperative period.

In-utero idiopathic ductal constriction: a prenatal manifestation of Alagille and Williams syndrome arteriopathy

OBJECTIVE

Williams and Alagille syndromes are genetic disorders associated with pathologic arterial narrowing. We hypothesized that fetal idiopathic ductus arteriosus (DA) constriction may represent a prenatal manifestation of the arteriopathy associated with these syndromes.

METHODS

Multi-institutional case series review of the pre- and postnatal medical records, echocardiograms, and genetic test results of fetuses presenting with idiopathic DA constriction.

RESULTS

We identified four cases of idiopathic fetal DA constriction at 21-36 weeks of gestation. All had right ventricular hypertension, dilation, hypertrophy, and dysfunction and either DA constriction or absence. All demonstrated progressive peripheral pulmonary artery stenosis after birth. Three met clinical diagnostic criteria for Alagille syndrome; two tested had confirmatory JAG1 mutations. One also developed supravalvar aortic stenosis after birth and was positive for 7q11.23 deletion (Williams syndrome).

CONCLUSION

This is the first case series to suggest that idiopathic fetal DA constriction may be a prenatal manifestation of genetic arteriopathy.

Frequent intragenic microdeletions of elastin in familial supravalvular aortic stenosis

BACKGROUND

Supravalvular aortic stenosis (SVAS) is a congenital heart disease affecting approximately 1:25,000 live births. SVAS may occur sporadically, be inherited in an autosomal dominant manner, or be associated with Williams-Beuren syndrome, a complex developmental disorder caused by a microdeletion of chromosome 7q11.23. ELN on 7q11.23, which encodes elastin, is the only known gene to be recurrently mutated in less than half of SVAS patients.

METHODS

Whole-exome sequencing (WES) was performed for seven familial SVAS families to identify other causative gene mutations of SVAS.

RESULTS

Three truncating mutations and three intragenic deletions affecting ELN were identified, yielding a diagnostic efficiency of 6/7 (85%). The deletions, which explained 3/7 of the present cohort, spanned 1-29 exons, which might be missed in the course of mutational analysis targeting point mutations. The presence of such deletions was validated by both WES-based copy number estimation and multiplex ligation-dependent probe amplification analyses, and their pathogenicity was reinforced by co-segregation with clinical presentations.

CONCLUSIONS

The majority of familial SVAS patients appear to carry ELN mutations, which strongly indicates that elastin is the most important causative gene for SVAS. The frequency of intragenic deletions highlights the need for quantitative tests to analyze ELN for efficient genetic diagnosis of SVAS.

A method for determining haploid and triploid genotypes and their association with vascular phenotypes in Williams syndrome and 7q11.23 duplication syndrome

Background

Williams syndrome ([WS], 7q11.23 hemideletion) and 7q11.23 duplication syndrome (Dup7) show contrasting syndromic symptoms. However, within each group there is considerable interindividual variability in the degree to which these phenotypes are expressed. Though software exists to identify areas of copy number variation (CNV) from commonly-available SNP-chip data, this software does not provide non-diploid genotypes in CNV regions. Here, we describe a method for identifying haploid and triploid genotypes in CNV regions, and then, as a proof-of-concept for applying this information to explain clinical variability, we test for genotype-phenotype associations.

Methods

Blood samples for 25 individuals with WS and 13 individuals with Dup7 were genotyped with Illumina-HumanOmni5M SNP-chips. PennCNV and in-house code were used to make genotype calls for each SNP in the 7q11.23 locus. We tested for association between the presence of aortic arteriopathy and genotypes of the remaining (haploid in WS) or duplicated (triploid in Dup7) alleles.

Results

Haploid calls in the 7q11.23 region were made for 99.0% of SNPs in the WS group, and triploid calls for 98.8% of SNPs in those with Dup7. The G allele of SNP rs2528795 in the ELN gene was associated with aortic stenosis in WS participants (p < 0.0049) while the A allele of the same SNP was associated with aortic dilation in Dup7.

Conclusions

Commonly available SNP-chip information can be used to make haploid and triploid calls in individuals with CNVs and then to relate variability in specific genes to variability in syndromic phenotypes, as demonstrated here using aortic arteriopathy. This work sets the stage for similar genotype-phenotype analyses in CNVs where phenotypes may be more complex and/or where there is less information about genetic mechanisms.

Electronic supplementary material

The online version of this article (10.1186/s12881-018-0563-3) contains supplementary material, which is available to authorized users.

Induced Pluripotent Stem Cells for Cardiovascular Disease Modeling and Precision Medicine: A Scientific Statement From the American Heart Association

Induced pluripotent stem cells (iPSCs) offer an unprece-dented opportunity to study human physiology and disease at the cellular level. They also have the potential to be leveraged in the practice of precision medicine, for example, personalized drug testing. This statement comprehensively describes the provenance of iPSC lines, their use for cardiovascular disease modeling, their use for precision medicine, and strategies through which to promote their wider use for biomedical applications. Human iPSCs exhibit properties that render them uniquely qualified as model systems for studying human diseases: they are of human origin, which means they carry human genomes; they are pluripotent, which means that in principle, they can be differentiated into any of the human body's somatic cell types; and they are stem cells, which means they can be expanded from a single cell into millions or even billions of cell progeny. iPSCs offer the opportunity to study cells that are genetically matched to individual patients, and genome-editing tools allow introduction or correction of genetic variants. Initial progress has been made in using iPSCs to better understand cardiomyopathies, rhythm disorders, valvular and vascular disorders, and metabolic risk factors for ischemic heart disease. This promising work is still in its infancy. Similarly, iPSCs are only just starting to be used to identify the optimal medications to be used in patients from whom the cells were derived. This statement is intended to (1) summarize the state of the science with respect to the use of iPSCs for modeling of cardiovascular traits and disorders and for therapeutic screening; (2) identify opportunities and challenges in the use of iPSCs for disease modeling and precision medicine; and (3) outline strategies that will facilitate the use of iPSCs for biomedical applications. This statement is not intended to address the use of stem cells as regenerative therapy, such as transplantation into the body to treat ischemic heart disease or heart failure.

Diagnosis and Management of Noncardiac Complications in Adults With Congenital Heart Disease: A Scientific Statement From the American Heart Association

Life expectancy and quality of life for those born with congenital heart disease (CHD) have greatly improved over the past 3 decades. While representing a great advance for these patients, who have been able to move from childhood to successful adult lives in increasing numbers, this development has resulted in an epidemiological shift and a generation of patients who are at risk of developing chronic multisystem disease in adulthood. Noncardiac complications significantly contribute to the morbidity and mortality of adults with CHD. Reduced survival has been documented in patients with CHD with renal dysfunction, restrictive lung disease, anemia, and cirrhosis. Furthermore, as this population ages, atherosclerotic cardiovascular disease and its risk factors are becoming increasingly prevalent. Disorders of psychosocial and cognitive development are key factors affecting the quality of life of these individuals. It is incumbent on physicians who care for patients with CHD to be mindful of the effects that disease of organs other than the heart may have on the well-being of adults with CHD. Further research is needed to understand how these noncardiac complications may affect the long-term outcome in these patients and what modifiable factors can be targeted for preventive intervention.