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Background: Telethonin (TCAP) is a Z‐disk protein that maintains cytoskeletal integrity and various signaling pathways in cardiomyocytes. TCAP is shown to modulate α‐subunit of the human cardiac sodium channel (hNav1.5) by direct interactions. Several TCAP variants are found in cardiomyopathies. We sought to investigate whether TCAP variants are associated with arrhythmia syndromes. Methods: Mutational analyses for TCAP were performed in 303 Japanese patients with Brugada syndrome, arrhythmogenic right ventricular cardiomyopathy, and J‐wave pattern ECG. Using patch‐clamp techniques, electrophysiological characteristics of hNav1.5 were studied in HEK‐293 cells stably expressing hNav1.5 and transiently transfected with wild‐type (WT) or variant TCAP. Results: We identified two TCAP variants, c.145G>A:p.E49K and c.458G>A:p.R153H, in four individuals. p.E49K was found in two patients with ARVC or BrS. p.R153H was found in two patients with BrS or J‐wave pattern ECG. No patient had variant hNav1.5. Patch‐clamp experiments demonstrated that peak sodium currents were significantly reduced in cells expressing p.R153H and p.E49K compared with WT‐TCAP (66%, p.R153H; 72%, p.E49K). Voltage dependency of peak IV curve was rightward‐shifted by 5 mV in cells expressing p.E49K compared with WT‐TCAP. Voltage dependency of activation was not leftward‐shifted by p.R153H, while voltage dependency of steady‐state inactivation was leftward‐shifted by p.E49K. Conclusions: We found two TCAP variants in the patients with BrS, J‐wave pattern ECG, and ARVC that can cause loss‐of‐function of the hNav1.5 in heterologous expression systems. Our observation suggests that these variants might impair INa and be associated with the patients' electrophysiological phenotypes. Further studies linking our experimental data to clinical phenotypes are warranted. [ABSTRACT FROM AUTHOR]

We report a case of emergent massive meconium peritonitis due to intrauterine volvulus without malrotation. Fetal ascites was detected on a regular ultrasonographic examination, and fetal distress was found on cardiotocographic monitoring. The mother had noticed a slight decrease in fetal movements over the preceding 24 hours. Prenatal magnetic resonance imaging allowed us to distinguish the meconium from fetal peritoneal fluid and to evaluate the degree of compression of the fetal thoracic cavity. The infant was delivered by emergency cesarean section and demonstrated tense abdominal ascites with edema at birth. She required cardiopulmonary resuscitation and immediate paracentesis. [ABSTRACT FROM AUTHOR]

Molecular autopsy has recently been gaining attention as a means of postmortem diagnosis; however, it is usually performed using the victim's blood sample at the time of death. Here, we report the first case of a deceased infant with Brugada syndrome whose diagnosis was made with banked cord blood. A seemingly healthy 1-year-old male infant collapsed while having a fever; this collapse was witnessed by his mother. Despite cardiopulmonary resuscitation, he died of ventricular fibrillation. No abnormalities of cardiac structure were identified on autopsy. Genomic samples were not stored at the time because of a lack of suspicion for familial arrhythmia. Five years later, his sister showed Brugada electrocardiogram pattern while febrile from Kawasaki disease. Their father showed a spontaneous type 1 Brugada electrocardiogram pattern. A heterozygous SCN5A p.R893C variant was found by genetic testing in the proband's father and sister. Furthermore, the proband's genetic testing was performed using his banked cord blood, which identified the same variant. Family history of Brugada syndrome with an SCN5A-R893C variant and clinical evidence led to a postmortem diagnosis of Brugada syndrome in the proband. Identification of this variant in this case later contributed to verifying SCN5A-R893C as a pathogenic variant through data accumulation. Banked cord blood may prove useful for conducting molecular autopsies in previously undiagnosed cases of sudden death in which genomic samples were not stored., Competing Interests: CONFLICT OF INTEREST DISCLOSURES: The authors have indicated they have no potential conflicts of interest to disclose., (Copyright © 2024 by the American Academy of Pediatrics.)

Objective: To clarify the necessity of acetylsalicylic acid (ASA) administration combined with intravenous immunoglobulin (IVIG) therapy in the treatment of acute Kawasaki disease., Design: Retrospective cohort study., Setting: Multicentre., Participants: This study included 735 patients with Kawasaki disease aged ≤10 years and hospitalised between 4 and 10 days of illness in eight Japanese hospitals from January 2016 to December 2020., Exposures: High-dose (HD) ASA was administered with initial IVIG to 333 patients in 6 hospitals (HD group). ASA was not administered routinely to 402 patients in the other two hospitals, and low-dose ASA was only administered when patients developed coronary artery lesions or pericardial effusion (non-HD group)., Primary and Secondary Outcome Measures: The primary outcome was the presence of coronary artery lesions, defined as a coronary artery diameter >+2.5 SD of body surface area within 1 month of onset. The secondary outcome was responsiveness to the initial IVIG therapy. Adjusted risk ratios for the outcomes were calculated using modified Poisson regression models. Bayesian analysis was conducted to estimate the posterior probability of the treatment effect of HD ASA under several prior distributions., Results: The incidence of coronary artery lesions was not significantly higher in the HD group than in the non-HD group (12/333 (3.6%) vs 15/402 (4.0%)). The proportion of non-responders to initial IVIG was similar between the two groups (HD group: 78/333 (23%); non-HD group: 83/402 (22%)). In the Bayesian analysis, considering a difference of ≤2% to be of no clinical importance, there was only a 9.3% chance of reduced risk of coronary artery lesions in the HD group compared with the non-HD group even with a strongly enthusiastic prior for HD treatment., Conclusions: Compared with HD ASA treatment, treatment without ASA in the acute phase of Kawasaki disease was not associated with increased complications from Kawasaki disease., Competing Interests: Competing interests: None., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Telethonin (TCAP) is a Z-disk protein that maintains cytoskeletal integrity and various signaling pathways in cardiomyocytes. TCAP is shown to modulate α-subunit of the human cardiac sodium channel (hNa v 1.5) by direct interactions. Several TCAP variants are found in cardiomyopathies. We sought to investigate whether TCAP variants are associated with arrhythmia syndromes., Methods: Mutational analyses for TCAP were performed in 303 Japanese patients with Brugada syndrome, arrhythmogenic right ventricular cardiomyopathy, and J-wave pattern ECG. Using patch-clamp techniques, electrophysiological characteristics of hNa v 1.5 were studied in HEK-293 cells stably expressing hNa v 1.5 and transiently transfected with wild-type (WT) or variant TCAP., Results: We identified two TCAP variants, c.145G>A:p.E49K and c.458G>A:p.R153H, in four individuals. p.E49K was found in two patients with ARVC or BrS. p.R153H was found in two patients with BrS or J-wave pattern ECG. No patient had variant hNa v 1.5. Patch-clamp experiments demonstrated that peak sodium currents were significantly reduced in cells expressing p.R153H and p.E49K compared with WT-TCAP (66%, p.R153H; 72%, p.E49K). Voltage dependency of peak IV curve was rightward-shifted by 5 mV in cells expressing p.E49K compared with WT-TCAP. Voltage dependency of activation was not leftward-shifted by p.R153H, while voltage dependency of steady-state inactivation was leftward-shifted by p.E49K., Conclusions: We found two TCAP variants in the patients with BrS, J-wave pattern ECG, and ARVC that can cause loss-of-function of the hNa v 1.5 in heterologous expression systems. Our observation suggests that these variants might impair I Na and be associated with the patients' electrophysiological phenotypes. Further studies linking our experimental data to clinical phenotypes are warranted., (© 2020 Wiley Periodicals LLC.)

Background: Several coronary artery Z score models have been developed. However, a Z score model derived by the lambda-mu-sigma (LMS) method has not been established., Methods: Echocardiographic measurements of the proximal right coronary artery, left main coronary artery, proximal left anterior descending coronary artery, and proximal left circumflex artery were prospectively collected in 3,851 healthy children ≤18 years of age and divided into developmental and validation data sets. In the developmental data set, smooth curves were fitted for each coronary artery using linear, logarithmic, square-root, and LMS methods for both sexes. The relative goodness of fit of these models was compared using the Bayesian information criterion. The best-fitting model was tested for reproducibility using the validation data set. The goodness of fit of the selected model was visually compared with that of the previously reported regression models using a Q-Q plot., Results: Because the internal diameter of each coronary artery was not similar between sexes, sex-specific Z score models were developed. The LMS model with body surface area as the independent variable showed the best goodness of fit; therefore, the internal diameter of each coronary artery was transformed into a sex-specific Z score on the basis of body surface area using the LMS method. In the validation data set, a Q-Q plot of each model indicated that the distribution of Z scores in the LMS models was closer to the normal distribution compared with previously reported regression models. Finally, the final models for each coronary artery in both sexes were developed using the developmental and validation data sets. A Microsoft Excel-based Z score calculator was also created, which is freely available online (http://raise.umin.jp/zsp/calculator/)., Conclusions: Novel LMS models with which to estimate the sex-specific Z score of each internal coronary artery diameter were generated and validated using a large pediatric population., (Copyright © 2016 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.)

A case of cerebral infarction in a 4-year-old male is described. The child presented with an acute onset of right hemiplegia, central facial palsy, and dysarthria. He had no predisposing factors for cerebral infarction. A computed tomography scan showed a diffuse low-density area in the territory of the left miiddle cerebral artery. Magnetic resonance angiography disclosed multiple irregular narrowings in the left anterior and middle cerebral arteries. He recovered spontaneously from the stroke with minimal long-term complications, and repeated angiography disclosed a complete regression of the vascular changes 2 months after the stroke. There was no recurrence of stroke after 2-year follow-up. This case demonstrates the importance of longitudinal angiographic follow-up in childhood cerebral infarction of idiopathic origin.