Sudden arrhythmia death syndrome in young victims: a five-year retrospective review and two-year prospective molecular autopsy study by next-generation sequencing and clinical evaluation of their first-degree relatives.

OBJECTIVE: Sudden arrhythmia death syndrome (SADS) accounts for about 30% of causes of sudden cardiac death (SCD) in young people. In Hong Kong, there are scarce data on SADS and a lack of experience in molecular autopsy. We aimed to investigate the value of molecular autopsy techniques for detecting SADS in an East Asian population. METHODS: This was a two-part study. First, we conducted a retrospective 5-year review of autopsies performed in public mortuaries on young SCD victims. Second, we conducted a prospective 2-year study combining conventional autopsy investigations, molecular autopsy, and cardiac evaluation of the first-degree relatives of SCD victims. A panel of 35 genes implicated in SADS was analysed by next-generation sequencing. RESULTS: There were 289 SCD victims included in the 5-year review. Coronary artery disease was the major cause of death (35%); 40% were structural heart diseases and 25% were unexplained. These unexplained cases could include SADS-related conditions. In the 2-year prospective study, 21 SCD victims were examined: 10% had arrhythmogenic right ventricular cardiomyopathy, 5% had hypertrophic cardiomyopathy, and 85% had negative autopsy. Genetic analysis showed 29% with positive heterozygous genetic variants; six variants were novel. One third of victims had history of syncope, and 14% had family history of SCD. More than half of the 11 first-degree relatives who underwent genetic testing carried related genetic variants, and 10% had SADS-related clinical features. CONCLUSION: This pilot feasibility study shows the value of incorporating cardiac evaluation of surviving relatives and next-generation sequencing molecular autopsy into conventional forensic investigations in diagnosing young SCD victims in East Asian populations. The interpretation of genetic variants in the context of SCD is complicated and we recommend its analysis and reporting by qualified pathologists.

Genetic basis of channelopathies and cardiomyopathies in Hong Kong Chinese patients: a 10-year regional laboratory experience.

INTRODUCTION: Hereditary channelopathies and cardiomyopathies are potentially lethal and are clinically and genetically heterogeneous, involving at least 90 genes. Genetic testing can provide an accurate diagnosis, guide treatment, and enable cascade screening. The genetic basis among the Hong Kong Chinese population is largely unknown. We aimed to report on 28 unrelated patients with positive genetic findings detected from January 2006 to December 2015. METHODS: Sanger sequencing was performed for 28 unrelated patients with a clinical diagnosis of channelopathies or cardiomyopathies, testing for the following genes: KCNQ1,KCNH2,KCNE1,KCNE2, and SCN5A, for long QT syndrome; SCN5A for Brugada syndrome; RYR2 for catecholaminergic polymorphic ventricular tachycardia; MYH7 and MYBPC3 for hypertrophic cardiomyopathy; LMNA for dilated cardiomyopathy; and PKP2 and DSP for arrhythmogenic right ventricular dysplasia/cardiomyopathy. RESULTS: There were 17 males and 11 females; their mean age at diagnosis was 39 years (range, 1-80 years). The major clinical presentations included syncope, palpitations, and abnormal electrocardiography findings. A family history was present in 13 (46%) patients. There were 26 different heterozygous mutations detected, of which six were novel-two in SCN5A (NM_198056.2:c.429del and c.2024-11T>A), two in MYBPC3 (NM_000256.3:c.906-22G>A and c.2105_2106del), and two in LMNA (NM_170707.3:c.73C>A and c.1209_1213dup). CONCLUSIONS: We have characterised the genetic heterogeneity in channelopathies and cardiomyopathies among Hong Kong Chinese patients in a 10-year case series. Correct interpretation of genetic findings is difficult and requires expertise and experience. Caution regarding issues of non-penetrance, variable expressivity, phenotype-genotype correlation, susceptibility risk, and digenic inheritance is necessary for genetic counselling and cascade screening.

Cryptococcal meningitis in an immunocompetent adolescent.

Cryptococcus neoformans is a rare cause of meningitis especially in immunocompetent children. Cryptococcal meningitis in a healthy Chinese adolescent is reported. She responded well to treatment with intravenous amphotericin and oral flucytosine.

Kawasaki disease in Hong Kong, 1994 to 2000.

OBJECTIVE: To describe the epidemiology, clinical characteristics, and management of Kawasaki disease in children in Hong Kong. DESIGN: Retrospective survey of medical records from July 1994 to June 1997, and prospective data collection from July 1997 to June 2000. SETTING: Hospitals with a paediatric unit in Hong Kong. PATIENTS: Patients diagnosed with Kawasaki disease between July 1994 and June 2000 in public hospitals in Hong Kong. MAIN OUTCOME MEASURES: Incidence of Kawasaki disease and coronary artery aneurysm rates. RESULTS: A total of 696 cases of Kawasaki disease were reported. There were 435 (62.5%) boys and 261 (37.5%) girls giving a male to female ratio of 1.7:1. The age ranged from 1 month to 15 years 5 months with a median of 1.7 years. Infants (<1 year) constituted the largest group of patients (223, 32.0%) and overall, 638 (91.7%) were younger than 5 years. Skin rash, conjunctivitis, and oral signs were among the principal clinical features present in over 80% of cases. Prominent cervical lymph nodes larger than 1.5 cm were less commonly found (24%). Coronary artery aneurysms or ectasia were present in 15.7% (109/696), 8.5% (59/696), and 5.0% (35/696) of patients at 2, 4, and 8 weeks, respectively. The incidence of Kawasaki disease per 100,000 children under 5 years was significantly higher in the prospective study period than in the retrospective period (39 vs 26, P<0.001). CONCLUSION: The incidence of Kawasaki disease is high in Hong Kong and is 39 per 100,000 children below 5 years of age. The coronary artery aneurysm prevalence is 5%. Intravenous gamma-globulin and high-dose aspirin is the mainstay of treatment.

Jervell-Lange Nielsen syndrome in a Pakistani family.

Congenital long QT syndrome is a rare hereditary disease that is related to the dysfunction of ion channels in cardiac cells. We report on a very rare case of its autosomal recessive form--the Jervell-Lange Nielsen syndrome--in a Pakistani family, which was diagnosed after the incidental finding of bradycardia in a newborn baby girl. We discuss the range of presentations in neonates; the importance of strong suspicion of the syndrome and family screening; the use of the diagnostic criteria and genetic tests; and the different management strategies.

Adolescent twin sisters with severe acute respiratory syndrome (SARS).

A novel coronavirus-associated communicable respiratory disease, severe acute respiratory syndrome (SARS), spread worldwide after an outbreak in Guangdong Province of the People's Republic of China in November 2002. Since late February 2003, there has been an epidemic in Hong Kong involving both adult and pediatric patients. The clinical course, intensive care, and outcome of adolescent twin sisters with SARS are described. Adolescents infected with SARS may develop severe illness as adults, and close monitoring for disease progression in terms of both clinical and radiologic deterioration is warranted.

Evaluation of the efficacy of treatment of Kawasaki disease before day 5 of illness.

We evaluated the efficacy of treating Kawasaki disease earlier than Day 5 of illness with a standard dose of immunoglobulin and aspirin. We performed a case-control study of patients with Kawasaki disease admitted to Princess Margaret Hospital from 1994 to 1999. Patients with pretreatment coronary aneurysm or those treated after day 10 of illness were excluded. All patients received immunoglobulin (2 g/kg) and aspirin (80-100 mg/kg/day) until fever subsided for 48 hours. Immunoglobulin retreatment was given for persistent fever 48 hours after the first dose of immunoglobulin or recrudescent fever. The case group consisted of 15 patients who received treatment earlier than day 5 of illness, and the control group consisted of 66 patients who were treated on or after day 5. Patients' sex, age, duration of posttreatment fever, need for additional immunoglobulin, and coronary artery status were noted. Treatment efficacy was assessed by the duration of posttreatment fever and the prevalence of coronary artery aneurysms. Eighty-one patients were included in this study. There were 15 patients in the case group and 66 in the control group. No significant difference was noted in age and sex between the case and control groups. Thirty-three percent (5/15) and 8% (5/66) of the case and control groups, respectively, had persistent/ recrudescent fever 48 hours after the first dose of immunoglobulin that required retreatment ( p = 0.017). Thirteen percent (2/15) and 5% (3/66) of the case and control groups, respectively, had coronary aneurysms ( p = 0.158). Treatment of Kawasaki disease before day 5 of illness was associated with persistent/recrudescent fever that required retreatment. However, there was no significant increase in the prevalence of coronary aneurysm if retreatment was given.

Clinical presentations and outcome of severe acute respiratory syndrome in children.

Hong Kong has been severely affected by severe acute respiratory syndrome (SARS). Contact in households and health-care settings is thought to be important for transmission, putting children at particular risk. Most data so far, however, have been for adults. We prospectively followed up the first ten children with SARS managed during the early phase of the epidemic in Hong Kong. All the children had been in close contact with infected adults. Persistent fever, cough, progressive radiographic changes of chest and lymphopenia were noted in all patients. The children were treated with high-dose ribavirin, oral prednisolone, or intravenous methylprednisolone, with no short-term adverse effects. Four teenagers required oxygen therapy and two needed assisted ventilation. None of the younger children required oxygen supplementation. Compared with adults and teenagers, SARS seems to have a less aggressive clinical course in younger children.