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Background A gain-of-function mutation in germline ABL1 causes a syndrome including congenital heart defects. However, the molecular mechanisms of this syndrome remain unknown. In this study, we found a novel ABL1 mutation in a Japanese family with ventricular septal defect, finger contracture, skin abnormalities and failure to thrive, and the molecular mechanisms of these phenotypes were investigated. Methods and results Whole-exome sequencing on several family members revealed a novel mutation (c.1522A > C, p.I508L) in the tyrosine kinase domain of ABL1, and complete co-segregation with clinical presentations was confirmed in all members. Wild-type and mutant ABL1 were transfected into human embryonic kidney 293 cells for functional analysis. Western blotting confirmed that tyrosine phosphorylation in STAT5, a substrate of ABL1, was enhanced, and the novel mutation was proved to be a gain-of-function mutation. Since this novel mutation in ABL1 enhances tyrosine kinase activity, phosphorylated proteome analysis was used to elucidate the molecular pathology. The proteome analysis showed that phosphorylation in proteins such as UFD1, AXIN1, ATRX, which may be involved in the phenotypes, was enhanced in the mutant group. Conclusions The onset of congenital heart defects associated with this syndrome appears to involve a mechanism caused by UFD1 common to 22q.11.2 deletion syndrome. On the other hand, AXIN1 and ATRX may be important in elucidating the mechanisms of other phenotypes, such as finger contracture and failure to thrive. Verification of these hypotheses would lead to further understanding of the pathophysiology and the development of treatment methods.

Pulmonary hypertension (PH) is associated with high morbidity in children undergoing hematopoietic stem cell transplantation (HSCT). However, owing to the lack of sequential echocardiography, the nature of the condition is not fully understood. This study was conducted to investigate whether routine echocardiography performed after HSCT could detect patients with PH at an earlier stage and elucidate the role of intervention using tadalafil. The study population comprised 93 consecutive children age18 years who underwent a total of 109 HSCTs. All patients underwent routine transthoracic echocardiography during HSCT. Four children (4%) with a median age of 4 years (range, 0.7 to 6 years) were found to have PH, and their median tricuspid regurgitation peak velocity (TRV) was 4.1 m/s (range, 3.5 to 4.2 m/s). PH was diagnosed at a median of 52 days (range, 21 to 118 days) after HSCT. Three of them were diagnosed with neuroblastoma, and 1 was diagnosed with infantile leukemia. One patient developed PH after autologous HSCT, and 3 received killer immunoglobulin-like receptor ligand-mismatched cord blood. Busulfan was used for conditioning in all patients, and the proportion of patients receiving this medication was significantly higher in the PH group compared with the non-PH group (100% versus 30%; P = .011). Three of the 4 patients had a durable response (TRV ≤2.8 m/s) at a median of 46 days (range, 14 to 79 days) after starting treatment with tadalafil. No patient experienced exacerbation of PH, and treatment was completed at median of 96 days (range, 46 to 212 days). Our data suggest that routine echocardiography monitoring after HSCT should be considered in children receiving busulfan, although the precise follow-up timing needs further study. In addition, safe and effective administration of tadalafil must be ensured by close monitoring.

Research Question Although assisted reproductive technology (ART) increases the risk of congenital heart disease (CHD), the relationship between ART and critical CHD (CCHD) that requires early intervention in neonates is unclear. The objective of this study was to investigate the proportion of ART across different types of neonatal CCHD in a Japanese population. Design This study is a retrospective analysis of 418 consecutive infants with CCHDs that required catheter treatment or surgery within the first 28 days of life or ductal-dependent lesions, in two paediatric centres in Japan, between January 2014 and December 2019. The proportion of ART in infants with each type of CCHD was evaluated. We also evaluated the proportion of ART in infants with univentricular heart defect (UVH) compared with those with biventricular heart defect (BVH). Results The study group included 229 boys and 189 girls, with a gestational age of 38±2 weeks. Overall, 61 infants (14.5%) were conceived by fertility treatment with 46 (11.0%) conceived by ART. UVH and BVH were identified in 111 infants (26.6%) and 307 infants (73.4%), respectively. The proportion of infants conceived by ART was significantly higher in UVH (16.2%) than in BVH (9.1%), regardless of maternal age and maternal history of miscarriage. Conclusions The proportion of ART in infants with CCHD, especially UVH, was high. These findings may be an important basis to consider the rationale for performing fetal echocardiography in fetuses conceived by ART.

The use of unilateral pulmonary artery occlusion (UPAO) test for the preoperative evaluation of pneumonectomy was reported in adult patients. On the contrary, in infants, no strategies have yet been recommended to predict hemodynamics after pneumonectomy, nor has use of the UPAO test been reported. We describe the first case of infant with abnormal pulmonary circulation in whom successful pneumonectomy was performed after preoperative evaluation using UPAO test. Right pneumonectomy was planned for an 8-month-old girl, because of decreased right pulmonary function, high risk of pneumothorax, and impaired left lung expansion due to overexpansion caused by severe left bronchial stenosis and bronchomalacia. However, she had also prolonged pulmonary hypertension and there was difficulty in accurate echocardiographic evaluation of its severity due to concomitant left pulmonary artery stenosis. Furthermore, contrast-enhanced computer tomography suggested a certain degree of right pulmonary venous flow, discordant with the result showing scarce right pulmonary flow in perfusion scintigraphy. Predicting postoperative hemodynamic changes was therefore considered difficult. To evaluate these concerns, we performed cardiac catheterization and UPAO test to simulate postoperative hemodynamics. Pulmonary arteriography showed decreased but significant right pulmonary arterial and venous flows. Measurements including pulmonary artery pressure and cardiac index showed no marked changes after occlusion. Based on UPAO test results, the operation was successfully performed and hemodynamics remained stable postoperatively. The UPAO test may be useful for infants with cardiopulmonary impairment to evaluate the tolerability of pneumonectomy.

A pregnant woman was referred to our hospital due to fetal cardiomegaly. We recognised a dilated umbilical vein, which raised a suspicion of placental chorioangioma. A male neonate was delivered at 37 weeks of gestation. The cardiomegaly was gradually improved. Pathological examination identified five non-giant placental chorioangiomas. Multiple non-giant chorioangiomas may cause fetal complications despite the difficulty of prenatal diagnosis.

A 14-year-old girl suddenly developed ventricular tachycardia and severe chest pain during hospitalisation for trauma surgery. CT revealed a needle in the pericardium. Careful interview elicited that she had inserted the needle by herself, and Munchausen syndrome was diagnosed. This is the first report of ventricular tachycardia caused by a foreign body in a patient with Munchausen syndrome.

Background The aim of this study was to investigate the prediction of postnatal prognosis using fetal and perinatal data in patients with primary congenital dilated cardiomyopathy (PCDCM), and to estimate the incidence of this disease. Methods We examined correlations between fetal or perinatal data and postnatal clinical course in a multicenter retrospective study of eight patients with PCDCM. Incidence was calculated in a population-based study. Results All patients developed heart failure at a median of 8 days (range, 0-43 days), and six patients died or required extracorporeal artificial heart therapy at a median of 67 days (range, 0-92 days). The cardiothoracic area ratio from fetal echocardiography, the Apgar score, and the standard deviation of birth weight correlated significantly with the date at onset of heart failure. However, no data correlated with survival. Cumulative incidence of PCDCM was calculated as 1.21 per 100 000 total births (95% confidence interval, 0.37 to 2.06). Conclusions Primary congenital dilated cardiomyopathy has a poor prognosis, but cardiothoracic area ratio from fetal echocardiography, body weight at birth, and Apgar score correlate with the timing of the onset of heart failure, and these indicators might therefore be useful for peri- and postnatal management.

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.