Functional characterization of variants found in Japanese patients with hereditary hemorrhagic telangiectasia.

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant form of vascular dysplasia. Genetic diagnosis is made by identifying loss-of-function variants in genes, such as ENG and ACVRL1. However, the causal mechanisms of various variants of unknown significance remains unclear. In this study, we analyzed 12 Japanese patients from 11 families who were clinically diagnosed with HHT. Sequencing analysis identified 11 distinct variants in ACVRL1 and ENG. Three of the 11 were truncating variants, leading to a definitive diagnosis, whereas the remaining eight were splice-site and missense variants that required functional analyses. In silico splicing analyses demonstrated that three variants, c.526-3C > G and c.598C > G in ACVRL1, and c.690-1G > A in ENG, caused aberrant splicing, as confirmed by a minigene assay. The five remaining missense variants were p.Arg67Gln, p.Ile256Asn, p.Leu285Pro, and p.Pro424Leu in ACVRL and p.Pro165His in ENG. Nanoluciferase-based bioluminescence analyses demonstrated that these ACVRL1 variants impaired cell membrane trafficking, resulting in the loss of bone morphogenetic protein 9 (BMP9) signal transduction. In contrast, the ENG mutation impaired BMP9 signaling despite normal cell membrane expression. The updated functional analysis methods performed in this study will facilitate effective genetic testing and appropriate medical care for patients with HHT.

A Noonan-like pediatric patient with a de novo CBL pathogenic variant and an RNF213 polymorphism p.R4810K presenting with cardiopulmonary arrest due to left main coronary artery ostial atresia.

Left main coronary artery ostial atresia (LMCAOA) is an extremely rare condition. Here, we report the case of a 14-year-old boy with Noonan syndrome-like disorder in whom LMCAOA was detected following cardiopulmonary arrest. The patient had been diagnosed with Noonan syndrome-like disorder with a pathogenic splice site variant of CBL c.1228-2 A > G. He suddenly collapsed when he was running. After administering two electric shocks using an automated external defibrillator, the patient's heartbeat resumed. Cardiac catheterization confirmed the diagnosis of LMCAOA. Left main coronary artery angioplasty was performed. The patient was discharged without neurological sequelae. Brain magnetic resonance imaging revealed asymptomatic Moyamoya disease. In addition, RNF213 c.14429 G > A p.R4810K was identified. There are no reports on congenital coronary malformations of compound variations of RNF213 and CBL. In contrast, the RNF213 p.R4810K polymorphism has been established as a risk factor for angina pectoris and myocardial infarction in adults, and several congenital coronary malformations due to genetic abnormalities within the RAS/MAPK signaling pathway have been reported. This report aims to highlight the risk of sudden death in patients with RASopathy and RNF213 p.R4810K polymorphism and emphasize the significance of actively searching for coronary artery morphological abnormalities in these patients.

Risk factors for hospitalisation due to respiratory syncytial virus infection in children receiving prophylactic palivizumab.

Respiratory syncytial virus (RSV) is a common pathogen that causes extremely severe respiratory symptoms in the first few weeks and months of life. In infants with cardiopulmonary diseases, RSV infections have a significant clinical impact. Palivizumab, a humanised monoclonal antibody for RSV, has been shown to significantly reduce the rate of hospitalisation of high-risk infants diagnosed with RSV. However, we have experienced a significant number of RSV infections in our institution that required hospitalisation or intensive care, despite the administration of palivizumab. This study aimed to analyse the risk factors associated with severe RSV despite the use of palivizumab. We retrospectively reviewed the medical records of 688 patients who visited or were admitted to our hospital and received palivizumab. Thirty-seven (5.4%) patients required hospitalisation for RSV, despite receiving palivizumab. In addition, 31 of these patients (83.8%) required hospitalisation out of season for palivizumab injection. Preterm birth (≤ 28-week gestation), bronchopulmonary dysplasia (BPD), and trisomy 21 were risk factors for RSV-related hospitalisation in infected patients, despite receiving palivizumab. Furthermore, subgroup analysis of 69 patients with RSV revealed that hemodynamically significant congenital heart disease (CHD) was also a risk factor for RSV-related hospitalisation.Conclusion: Preterm birth (≤ 28 weeks of gestation), BPD, trisomy 21, hemodynamically significant CHD, and CHD requiring surgery or cardiac catheterisation/intervention during infancy could be considered when determining whether year-round administration of palivizumab is appropriate. What is Known: • Respiratory syncytial virus causes severe respiratory symptoms in infants, particularly those with cardiopulmonary diseases. • The use of palivizumab has reduced the rate of hospitalisation of infants diagnosed with RSV. Despite this, the rate of hospitalisation is still high. What is New: • We identified that preterm birth (≤ 28-week gestation), bronchopulmonary dysplasia, trisomy 21, and hemodynamically significant congenital heart disease were risk factors for RSV-related hospitalisation, even after receiving palivizumab treatment. • High-risk infants should be closely monitored and the prolonged use of palivizumab should be considered.

Left ventricular inflow obstruction due to a coronary arteriovenous fistula: a paediatric case report.

BACKGROUND: We report a rare case of left ventricular inflow obstruction from a branch of the left circumflex coronary artery to the right atrium caused by a coronary arteriovenous fistula (CAVF) in a young Japanese male child. CASE PRESENTATION: The patient was diagnosed with CAVF following a heart murmur shortly after birth. The left-to-right shunt caused right ventricular volume overload and pulmonary congestion. An emergency surgical intervention was performed for the CAVF on day 6 after birth. However, by 5 years of age, his left ventricular inflow obstruction worsened. We found an abnormal blood vessel originating from the proximal part of a branch of the left circumflex coronary artery, circling the outside of the mitral valve annulus along the medial side of the coronary sinus. As the child gets older, the blood inflow into the left ventricle might get restricted further, resulting in left-sided heart failure. CONCLUSION: Our findings suggest that even after CAVF closure surgery, it is essential to monitor for complications caused by progressive dilatation of a persistent CAVF.

Pulmonary vasodilators can lead to various complications in pulmonary "arterial" hypertension associated with congenital heart disease.

Congenital heart disease-associated pulmonary arterial hypertension (CHD-PAH) is one of the major complications in patients with CHD. A timely closure of the left-to-right shunt will generally result in the normalization of the pulmonary hemodynamics, but a few patients have severe prognosis in their early childhood. We hypothesized that wide-ranging pathological mechanism in PAH could elucidate the clinical state of severe CHD-PAH. Using electronic medical records, we retrospectively analyzed six infants with severe CHD-PAH who had treatment-resistant PH. All patients were born with congenital malformation syndrome. After starting on a pulmonary vasodilator, five of the six patients developed complications including pulmonary edema and interstitial lung disease (ILD), and four patients had alveolar hemorrhage. After steroid therapy, the clinical condition improved in four patients, but two patients died. The autopsy findings in one of the deceased patients indicated the presence of recurrent alveolar hemorrhage, pulmonary venous hypertension, ILD, and PAH. Based on the clinical course of these CHD-PAH in patients and the literature, CHD-PAH can occur with pulmonary vascular obstructive disease (PVOD)/pulmonary capillary hemangiomatosis (PCH), ILD, and/or alveolar hemorrhage. The severity of CHD-PAH may depend on a genetic disorder, respiratory infection, and upper airway stenosis. Additionally, pulmonary vasodilators may be involved in the development of PVOD/PCH and ILD. When patients with CHD-PAH show unexpected deterioration, clinicians should consider complications associated with PVOD/PCH and/or pulmonary disease. In addition, the choice of upfront combination therapy for pediatric patients with CHD-PAH should be selected carefully.

Impact of the COVID-19 pandemic on pediatric out-of-hospital cardiac arrest outcomes in Japan.

This study investigates the impact of the COVID-19 pandemic on pediatric out-of-hospital cardiac arrest (OHCA) outcomes in Japan, aiming to address a critical research gap. Analyzing data from the All-Japan Utstein registry covering pediatric OHCA cases from 2018 to 2021, the study observed no significant changes in one-month survival, neurological outcomes, or overall performance when comparing the pre-pandemic (2018-2019) and pandemic (2020-2021) periods among 6765 cases. However, a notable reduction in pre-hospital return of spontaneous circulation (ROSC) during the pandemic (15.1-13.1%, p = .020) was identified. Bystander-initiated chest compressions and rescue breaths declined (71.1-65.8%, 22.3-13.0%, respectively; both p < .001), while bystander-initiated automated external defibrillator (AED) use increased (3.7-4.9%, p = .029). Multivariate logistic regression analyses identified factors associated with reduced pre-hospital ROSC during the pandemic. Post-pandemic, there was no noticeable change in the one-month survival rate. The lack of significant change in survival may be attributed to the negative effects of reduced chest compressions and ventilation being offset by the positive impact of widespread AED availability in Japan. These findings underscore the importance of innovative tools and systems for safe bystander cardiopulmonary resuscitation during a pandemic, providing insights to optimize pediatric OHCA care.

Whole-exome sequencing reveals the genetic causes and modifiers of moyamoya syndrome.

Moyamoya vasculopathy secondary to various genetic disorders is classified as moyamoya syndrome (MMS). Recent studies indicate MMS occurs due to a combination of genetic modifiers and causative mutations for the primary genetic disorders. We performed whole-exome sequencing (WES) in 13 patients with various genetic disorders who developed MMS. WES successfully revealed the genetic diagnoses of neurofibromatosis type 1 (NF-1), Down syndrome, multisystemic smooth muscle dysfunction syndrome, Noonan syndrome, and alpha thalassemia. The previously reported modifier genes, RNF213 and MRVI1, were confirmed in the NF-1 and Down syndrome cases. Further analysis revealed rare hypomorphic variants in the causative genes of the primary disorders underlying MMS, such as Alagille syndrome and Rasopathies, conferred susceptibility to MMS. Genes involved in the development of pulmonary arterial hypertension (PAH), such as ABCC8 and BMPR2, were also identified as potential modifiers. The rare variants in the MMS and PAH genes were significantly enriched in the eight Japanese patients with MMS compared with the 104 Japanese individuals from the 1000 Genomes Project. Disease genes associated with the arterial occlusive conditions represented by those of Rasopathies and PAH may provide novel diagnostic markers and future therapeutic targets for MMS as well as moyamoya disease with an unknown cause.

Identification of Prostaglandin I2 Synthase Rare Variants in Patients With Williams Syndrome and Severe Peripheral Pulmonary Stenosis.

BACKGROUND: Peripheral pulmonary stenosis (PPS) is a condition characterized by the narrowing of the pulmonary arteries, which impairs blood flow to the lung. The mechanisms underlying PPS pathogenesis remain unclear. Thus, the aim of this study was to investigate the genetic background of patients with severe PPS to elucidate the pathogenesis of this condition. METHODS AND RESULTS: We performed genetic testing and functional analyses on a pediatric patient with PPS and Williams syndrome (WS), followed by genetic testing on 12 patients with WS and mild-to-severe PPS, 50 patients with WS but not PPS, and 21 patients with severe PPS but not WS. Whole-exome sequencing identified a rare PTGIS nonsense variant (p.E314X) in a patient with WS and severe PPS. Prostaglandin I2 synthase (PTGIS) expression was significantly downregulated and cell proliferation and migration rates were significantly increased in cells transfected with the PTGIS p.E314X variant-encoding construct when compared with that in cells transfected with the wild-type PTGIS-encoding construct. p.E314X reduced the tube formation ability in human pulmonary artery endothelial cells and caspase 3/7 activity in both human pulmonary artery endothelial cells and human pulmonary artery smooth muscle cells. Compared with healthy controls, patients with PPS exhibited downregulated pulmonary artery endothelial prostaglandin I2 synthase levels and urinary prostaglandin I metabolite levels. We identified another PTGIS rare splice-site variant (c.1358+2T>C) in another pediatric patient with WS and severe PPS. CONCLUSIONS: In total, 2 rare nonsense/splice-site PTGIS variants were identified in 2 pediatric patients with WS and severe PPS. PTGIS variants may be involved in PPS pathogenesis, and PTGIS represents an effective therapeutic target.

Corrigendum: Use of the index of pulmonary vascular disease for predicting longterm outcome of pulmonary arterial hypertension associated with congenital heart disease.

[This corrects the article DOI: 10.3389/fcvm.2023.1212882.].

A case of infantile Barth syndrome with severe heart failure: Importance of splicing variants in the TAZ gene.

Barth syndrome (BTHS) is an X-linked disorder characterized by cardiomyopathy, skeletal myopathy, and 3-methylglutaconic aciduria. The causative pathogenic variants for BTHS are in TAZ, which encodes a putative acyltransferase named tafazzin and is involved in the remodeling of cardiolipin in the inner mitochondrial membranes. Pathogenic variants in TAZ result in mitochondrial structural and functional abnormalities. We report a case of infantile BTHS with severe heart failure, left ventricular noncompaction, and lactic acidosis, having a missense c.640C>T (p.His214Tyr) variant in TAZ, which is considered a pathogenic variant based on the previously reported amino acid substitution at the same site (c.641A>G, p.His214Arg). However, in this previously reported case, heart function was compensated and not entirely similar to the present case. Silico prediction analysis suggested that c.640C>T could alter the TAZ messenger RNA (mRNA) splicing process. TAZ mRNAs in isolated peripheral mononuclear cells from the patient and in vitro splicing analysis using minigenes of TAZ found an 8 bp deletion at the 3' end of exon 8, which resulted in the formation of a termination codon in the coding region of exon 9 (H214Nfs*3). These findings suggest that splicing abnormalities should always be considered in BTHS.

Use of the index of pulmonary vascular disease for predicting long-term outcome of pulmonary arterial hypertension associated with congenital heart disease.

Aims: Limited data exist on risk factors for the long-term outcome of pulmonary arterial hypertension (PAH) associated with congenital heart disease (CHD-PAH). We focused on the index of pulmonary vascular disease (IPVD), an assessment system for pulmonary artery pathology specimens. The IPVD classifies pulmonary vascular lesions into four categories based on severity: (1) no intimal thickening, (2) cellular thickening of the intima, (3) fibrous thickening of the intima, and (4) destruction of the tunica media, with the overall grade expressed as an additive mean of these scores. This study aimed to investigate the relationship between IPVD and the long-term outcome of CHD-PAH. Methods: This retrospective study examined lung pathology images of 764 patients with CHD-PAH aged <20 years whose lung specimens were submitted to the Japanese Research Institute of Pulmonary Vasculature for pulmonary pathological review between 2001 and 2020. Clinical information was collected retrospectively by each attending physician. The primary endpoint was cardiovascular death. Results: The 5-year, 10-year, 15-year, and 20-year cardiovascular death-free survival rates for all patients were 92.0%, 90.4%, 87.3%, and 86.1%, respectively. The group with an IPVD of ≥2.0 had significantly poorer survival than the group with an IPVD <2.0 (P = .037). The Cox proportional hazards model adjusted for the presence of congenital anomaly syndromes associated with pulmonary hypertension, and age at lung biopsy showed similar results (hazard ratio 4.46; 95% confidence interval: 1.45-13.73; P = .009). Conclusions: The IPVD scoring system is useful for predicting the long-term outcome of CHD-PAH. For patients with an IPVD of ≥2.0, treatment strategies, including choosing palliative procedures such as pulmonary artery banding to restrict pulmonary blood flow and postponement of intracardiac repair, should be more carefully considered.

An Adolescent Patient With Idiopathic Pulmonary Arterial Hypertension Weaned Off Intravenous Epoprostenol Following Treatment With Selexipag: A Case Report.

Idiopathic pulmonary arterial hypertension (PAH) is a rare, progressive disease affecting the pulmonary arteries. Epoprostenol, a synthetic prostaglandin analog, is the most potent pharmacological treatment modality used in patients with PAH. However, it requires continuous intravenous infusion, which negatively impacts the patient's quality of life and frequently results in complications, such as catheter-related bloodstream infection. We weaned an adolescent female patient off epoprostenol by gradually introducing oral selexipag over a sustained period, following many years of continuous intravenous epoprostenol use alone. Oral selexipag might have an efficacy comparable to epoprostenol in young patients with PAH.

A Cardiac Arrest Case due to Left Coronary Artery Compression in Congenital Heart Disease-Associated Pulmonary Arterial Hypertension.

We report the case of an adult who had a cardiac arrest in the setting of pulmonary hypertension and a previously repaired intermediate atrioventricular septal defect, with left main coronary trunk stenosis due to dilatation of the main pulmonary artery. In patients with pulmonary hypertension exhibiting anginal symptoms, it is advisable to perform chest contrast computed tomography to confirm the pulmonary artery diameter and the presence of coronary artery compression. In addition, our case highlights the importance of early collaboration among specialists during the transition from adolescence to adulthood.

Nous décrivons le cas d'un adulte ayant subi un arrêt cardiaque alors qu'il présentait une hypertension pulmonaire et qu'il avait déjà subi la réparation d'une communication septale auriculoventriculaire intermédiaire, avec sténose de l'artère coronaire gauche principale causée par la dilatation de l'artère pulmonaire principale. Chez les patients atteints d'hypertension pulmonaire qui présentent des symptômes angineux, il est recommandé d'effectuer une tomodensitométrie thoracique avec produit de contraste pour confirmer le diamètre de l'artère pulmonaire et la présence d'une compression de l'artère coronaire. Notre cas souligne également l'importance d'établir sans tarder une collaboration entre spécialistes lors de la transition entre l'adolescence et l'âge adulte.

A case report: Twin sisters with restrictive cardiomyopathy associated with rare mutations in the cardiac troponin I gene.

Restrictive cardiomyopathy (RCM) is a rare cardiomyopathy in children, and its prognosis until now, has been poor. Recently some sarcomeric mutations have been reported as disease-causing genes of RCM. However, the genotype-phenotype correlation is not fully understood. Additionally, prognostic factors including sudden death in patients with RCM have not been elucidated. We report our experience in treating twin sisters with RCM or hypertrophic cardiomyopathy with RCM phenotype, both carriers of the same mutation in TNNI3, which encodes one of the major sarcomeric proteins in myofibrils. They were both diagnosed with RCM by cardiac catheterization at the age of 11 years. Despite appropriate follow-up and medical treatment, one died suddenly at the age of 11 years and the other also died at the age of 15 years due to heart failure while awaiting heart transplantation. In addition to our cases, other reports of younger fatal cases with RCM carrying TNNI3 mutations may suggest it as one of the prognostic factors. Genetic diagnosis is important in the clinical diagnosis, management, and treatment of cardiomyopathy. .

Total Anomalous Pulmonary Venous Connection with Lethal Pulmonary Venous Obstruction Managed by Multidisciplinary Cooperation.

BACKGROUND: Total anomalous pulmonary venous connection (TAPVC) is a critical congenital heart disease for which emergency surgery is required after birth. In cases of no intervention, TAPVC is associated with a high mortality rate in the first year of life. Although foetal echocardiographic techniques for diagnosing TAPVC have improved, TAPVC remains one of the most difficult congenital heart diseases to diagnose via foetal echocardiography. Here, we report a case of TAPVC with pulmonary venous obstruction (PVO), which was diagnosed via foetal echocardiography. Case Presentation. On foetal echocardiography at 32 weeks' gestation, a large atrial septal defect, enlarged superior vena cava, and continuous flow pattern in the vertical vein from the common chamber were observed in the foetus. Paediatric cardiologists and cardiac surgeons, neonatologists, and obstetricians planned to perform a caesarean section and emergency heart surgery. The male infant was born at 37 weeks' gestation via caesarean section, and postnatal echocardiography revealed PVO at the confluence of the superior vena cava and common chamber. Similarly, chest computed tomography confirmed the foetal diagnosis. The postnatal diagnoses were TAPVC type Ib, PVO, atrial septal defect, and patent ductus arteriosus. Surgical repair of the TAPVC was initiated within the first 3 hours of life. Screening brain echocardiography and head computed tomography revealed intracranial haemorrhage and hydrocephalus. Therefore, the patient underwent emergency bilateral external drainage on day 13. On day 48, a ventriculoperitoneal shunt was inserted owing to progressive brain ventricular dilatation. The patient was discharged home on postoperative day 68. CONCLUSIONS: Although the prognosis of TAPVC with PVO remains poor, continuous observation through foetal echocardiography and early interdepartmental collaboration can result in good outcomes.

Diagnostic dilemma in a case of obstructive sleep apnoea syndrome with reversible pulmonary hypertension and right heart failure: A case report.

Childhood obstructive sleep apnoea syndrome (OSAS) secondary to adenoid hyperplasia is known to give rise to pulmonary hypertension. However, we present a case of a toddler with pulmonary hypertension (PH) and right heart failure due to OSAS, the cause of which is difficult to identify. After the patient underwent an adenotonsillectomy, OSAS disappeared and the PH eventually resolved. Both paediatricians and otolaryngologists should know that paediatric OSAS can occur even in the setting of mild, clinically insignificant palatine tonsil hypertrophy and adenoid hyperplasia. Surgical intervention should be considered without losing the opportunity if it could be the cause of PH.

Role of BRCA1-associated protein (BRAP) variant in childhood pulmonary arterial hypertension.

Although mutations in several genes have been reported in pulmonary arterial hypertension (PAH), most of PAH cases do not carry these mutations. This study aimed to identify a novel cause of PAH. To determine the disease-causing variants, direct sequencing and multiplex ligation-dependent probe amplification were performed to analyze 18 families with multiple affected family members with PAH. In one of the 18 families with PAH, no disease-causing variants were found in any of BMPR2, ACVRL1, ENG, SMAD1/4/8, BMPR1B, NOTCH3, CAV1, or KCNK3. In this family, a female proband and her paternal aunt developed PAH in their childhood. Whole-exome next-generation sequencing was performed in the 2 PAH patients and the proband's healthy mother, and a BRCA1-associated protein (BRAP) gene variant, p.Arg554Leu, was identified in the 2 family members with PAH, but not in the proband's mother without PAH. Functional analyses were performed using human pulmonary arterial smooth muscle cells (hPASMCs). Knockdown of BRAP via small interfering RNA in hPASMCs induced p53 signaling pathway activation and decreased cell proliferation. Overexpression of either wild-type BRAP or p.Arg554Leu-BRAP cDNA constructs caused cell death confounding these studies, however we observed higher levels of p53 signaling inactivation and hPASMC proliferation in cells expressing p.Arg554Leu-BRAP compared to wild-type BRAP. In addition, p.Arg554Leu-BRAP induced decreased apoptosis of hPASMCs compared with wild-type BRAP. In conclusion, we have identified a novel variant of BRAP in a Japanese family with PAH and our results suggest it could have a gain-of-function. This study sheds light on new mechanism of PAH pathogenesis.