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Introduction: Congenital long QT syndrome (LQTS) is a genetically transmitted cardiac channelopathy that can lead to sudden cardiac death. This study aimed to report the clinical and genetic characteristics of all young patients diagnosed with LQTS in the only tertiary paediatric cardiology centre in Hong Kong., Methods: This is a retrospective review of all paediatric and young adult patients diagnosed at our centre with LQTS from January 1997 to December 2016. The diagnosis of LQTS was established with a corrected QT interval (QTc) ≥480 ms, Schwartz score of >3 points, or the presence of a pathogenic mutation., Results: Fifty-nine patients (33 males) from 52 families were included, with a mean age of 8.17 years (range, 0.00-16.95 years) at presentation. Five patients had concomitant congenital heart diseases. The mean follow-up duration was 5.33 ± 4.65 years. The mean QTc in the cohort was 504 ± 47 ms. They presented with syncope and convulsion (49%), cardiac arrest (10%), bradycardia and neonatal atrioventricular block (12%). Fifteen (25%) patients were asymptomatic at diagnosis. Thirty-eight (64.4%) patients were confirmed to have a pathogenic mutation for LQTS genes. Forty-five (76.3%) patients received beta blocker therapy. Thirteen (22.0%) patients required implantable cardioverter defibrillator. There was no mortality in the study period. The 1-, 5-, and 10-year breakthrough cardiac event-free rates were 93.0%, 80.7%, and 72.6%, respectively., Conclusion: Identification of the disorder, administration of beta blockers, and lifestyle modification can prevent subsequent cardiac events in LQTS. Genotyping in patients with LQTS is essential in guiding medical therapy and improving prognosis.

Isolated primary hepatocytes from the liver are very similar to in vivo native liver hepatocytes, but they have the disadvantage of a limited lifespan in 2D culture. Although a sandwich culture and 3D organoids with mesenchymal stem cells (MSCs) as an attractive assistant cell source to extend lifespan can be used, it cannot fully reproduce the in vivo architecture. Moreover, long-term 3D culture leads to cell death because of hypoxic stress. Therefore, to overcome the drawback of 2D and 3D organoids, we try to use a 3D printing technique using alginate hydrogels with primary hepatocytes and MSCs. The viability of isolated hepatocytes was more than 90%, and the cells remained alive for 7 days without morphological changes in the 3D hepatic architecture with MSCs. Compared to a 2D system, the expression level of functional hepatic genes and proteins was higher for up to 7 days in the 3D hepatic architecture. These results suggest that both the 3D bio-printing technique and paracrine molecules secreted by MSCs supported long-term culture of hepatocytes without morphological changes. Thus, this technique allows for widespread expansion of cells while forming multicellular aggregates, may be applied to drug screening and could be an efficient method for developing an artificial liver.

Objectives: To examine the molecular pathogenetic mechanisms, (epi)genotype-phenotype correlation, and the performance of the three clinical scoring systems-namely Netchine et al, Bartholdi et al, and Birmingham scores-for patients with Silver-Russell syndrome in Hong Kong., Methods: This retrospective case series was conducted at two tertiary genetic clinics, the Clinical Genetic Service, Department of Health, and clinical genetic clinic in Queen Mary Hospital in Hong Kong. All records of patients with suspected Silver-Russell syndrome under the care of the two genetic clinics between January 2010 and September 2015 were retrieved from the computer database., Results: Of the 28 live-birth patients with Silver-Russell syndrome, 35.7% had H19 loss of DNA methylation, 21.4% had maternal uniparental disomy of chromosome 7, 3.6% had mosaic maternal uniparental disomy of chromosome 11, and the remaining 39.3% were Silver-Russell syndrome of unexplained molecular origin. No significant correlation between (epi)genotype and phenotype could be identified between H19 loss of DNA methylation and maternal uniparental disomy of chromosome 7. Comparison of molecularly confirmed patients and patients with Silver-Russell syndrome of unexplained origin revealed that postnatal microcephaly and café-au-lait spots were more common in the latter group, and body and limb asymmetry was more common in the former group. Performance analysis showed the Netchine et al and Birmingham scoring systems had similar sensitivity in identifying Hong Kong Chinese subjects with Silver-Russell syndrome., Conclusion: This is the first territory-wide study of Silver-Russell syndrome in Hong Kong. The clinical features and the spectrum of underlying epigenetic defects were comparable to those reported in western populations.

Objective: To report our experience in the management of catecholaminergic polymorphic ventricular tachycardia in Hong Kong Chinese children., Methods: This case series study was conducted in a tertiary paediatric cardiology centre in Hong Kong. All paediatric patients diagnosed at our centre with catecholaminergic polymorphic ventricular tachycardia from January 2008 to October 2014 were included., Results: Ten patients (five females and five males) were identified. The mean age at presentation and at diagnosis were 11.0 (standard deviation, 2.9) years and 12.5 (2.8) years, respectively. The mean delay time from first presentation to diagnosis was 1.5 (standard deviation, 1.3) years. They presented with recurrent syncope and six patients had a history of aborted cardiac arrest. Four patients were initially misdiagnosed to have epilepsy. Catecholaminergic polymorphic ventricular tachycardia was diagnosed by electrocardiogram at cardiac arrest (n=2), or provocation test, either by catecholamine infusion test (n=6) or exercise test (n=2). Mutations of the RyR2 gene were confirmed in six patients. Nine patients were commenced on beta-blockers after diagnosis. Despite medications, three patients developed aborted or resuscitated cardiac arrest (n=2) and syncope (n=1). Left cardiac sympathetic denervation was performed in five patients and an implantable cardioverter defibrillator was implanted in another. There was no mortality during follow-up., Conclusions: Catecholaminergic polymorphic ventricular tachycardia should be considered in children who present with recurrent syncope during exercise or emotional stress. Despite beta-blocker treatment, recurrent ventricular arrhythmias occur and may result in cardiac arrest.

Approximately 15% of preterm infants may develop postnatal cytomegalovirus (CMV) infection from seropositive mothers via breast milk and are at risk for neurological sequelae in childhood. The aims of this study were to assess the effects and outcomes on growth, neurodevelopmental status, and hearing in very low birth weight (VLBW) premature infants with postnatal CMV infection via breast milk at the corrected age of 12 and 24 months.The prospective follow-up study population comprised all living preterm children (n = 55) with a birth weight ≤1500 g and gestational age of ≤35 weeks, who had been participated in our "postnatal CMV infection via breast milk" studies in 2000 and 2009, respectively. The cohort of children was assessed at 12 and 24 months. Clinical outcomes were documented during hospitalization and after discharge. Long-term outcomes included anthropometry, audiologic tests, gross motor quotient, Infant International Battery, and neurodevelopmental outcomes; all were assessed at postcorrected age in 12 and 24 months during follow-up visits.Of the 55 infants enrolled in the study (4 noninfected infants were excluded because their parents did not join this follow-up program later), 14 infants postnatally acquired CMV infection through breast-feeding (infected group) and were compared with 41 infants without CMV infection (control group). No significant differences were observed between the groups with regard to baseline characteristics, clinical outcomes, anthropometry, or psychomotor and mental development on the Bayley scale of infant development. None of the infants had CMV-related death or permanent sensorineural hearing loss.Transmission of CMV from seropositive mother via breast milk to preterm infants does not appear at this time to have major adverse effects on clinical outcomes, growth, neurodevelopmental status, and hearing function at 12 and 24 months corrected age.

F-FDG PET/CT is a promising tool in detecting aortic graft infection. Present study investigated the value of dual-time-point F-FDG PET/CT imaging (DTPI) with delayed imaging in assessing aortic graft infection.Twenty-nine patients with suspected aortic graft infection were prospectively enrolled in this DTPI study. Two nuclear medicine physicians read all the images and achieved consensus about the measurement of maximal standardized uptake value (SUVmax) and grading of image quality. The percentages of SUVmax change between initial and delayed images were recorded as retention index (RI); sensitivity, specificity, and accuracy were calculated based on reference standard.All the 5 infected aortic grafts had positive RIs, which were generally higher than that of noninfected grafts. Those noninfected grafts had variable RIs. Seven patients had improved image quality in delayed imaging. DTPI with delayed image detected all the infected grafts with improved specificity (88%) and accuracy (90%), providing conspicuous delineation of the infected graft extent.In conclusion, noninfected aortic grafts had more variable RIs than infected ones. DTPI might be useful for detecting aortic graft infection, improving image quality, and enhancing delineation of the infected aortic grafts.