RESUMO
BACKGROUND: Restrictive cardiomyopathy (RCM) is rare in childhood, but has a grave prognosis. The cause of disease in most cases is unknown. OBJECTIVE: To determine the prevalence of sarcomere protein gene mutations in children with idiopathic RCM. METHODS: Twelve patients (9 female, mean age 5.1 years) with idiopathic RCM referred between 1991 and August 2006 underwent detailed clinical and genetic evaluation. Nine had received cardiac transplants at the time of the study. The entire coding sequences of the genes encoding eight cardiac sarcomere proteins and desmin were screened for mutations. Familial evaluation was performed on first-degree relatives. RESULTS: Four patients (33%) had a family history of cardiomyopathy: RCM (n = 2); dilated cardiomyopathy (n = 1) and left ventricular non-compaction (n = 1). Sarcomere protein gene mutations were identified in four patients (33%): 2 in the cardiac troponin I gene (TNNI3) and 1 each in the troponin T (TNNT2) and alpha-cardiac actin (ACTC) genes. Two were de novo mutations and 3 were new mutations. All mutations occurred in functionally important and conserved regions of the genes. CONCLUSIONS: Sarcomere protein gene mutations are an important cause of idiopathic RCM in childhood. We describe the first mutation in ACTC in familial RCM. The identification of RCM in a child should prompt consideration of sarcomere protein disease as a possible cause and warrants clinical evaluation of the family.
Assuntos
Actinas/genética , Cardiomiopatia Restritiva/genética , MAP Quinase Quinase Quinases/genética , Troponina T/genética , Adolescente , Sequência de Aminoácidos , Cardiomiopatia Dilatada/genética , Cardiomiopatia Hipertrófica Familiar/genética , Cardiomiopatia Restritiva/patologia , Proteínas de Transporte/genética , Criança , Pré-Escolar , Análise Mutacional de DNA/métodos , Feminino , Ligação Genética/genética , Humanos , Lactente , Masculino , Mutação de Sentido Incorreto/genética , Linhagem , Proteínas Serina-Treonina Quinases , Sarcômeros/genética , Sarcômeros/fisiologiaRESUMO
BACKGROUND: In adults with hypertrophic cardiomyopathy (HCM), plasma B-type natriuretic peptide (BNP) levels correlate with dyspnoea class and other markers of disease severity. In children with HCM, symptoms are a poor guide to disease severity and no studies have evaluated the clinical utility of BNP testing. OBJECTIVE: To assess the relation of BNP levels to symptoms and markers of disease severity in children with HCM. METHODS: Forty-four consecutive patients with HCM (27 male, age
Assuntos
Cardiomiopatia Hipertrófica/sangue , Peptídeo Natriurético Encefálico/metabolismo , Adolescente , Criança , Pré-Escolar , Diástole/fisiologia , Feminino , Humanos , Lactente , Masculino , Análise Multivariada , Disfunção Ventricular Esquerda/sangueRESUMO
OBJECTIVE: To determine the range of survival rates of patients with hypertrophic cardiomyopathy (HCM) by comparing and contrasting the natural history of a cohort of patients seen between 1988 and 2002 with that of other published series. METHODS: 956 adult (> or = 16 years old) patients with HCM (572 men, mean (SD) age 42 (15) years, range 16-88) were evaluated by ECG, Holter, exercise testing, and echocardiography. Patient characteristics and survival data were compared with those in natural history studies from referral and non-referral centres published between 1960 and January 2003. RESULTS: The duration of follow up was 69 (45) months. 120 (12.6%) patients died or underwent cardiac transplantation. Sudden cardiac death (n = 48) was the most common mode of death. The annual rate of sudden death or implantable cardioverter-defibrillator discharge was 1.02 (95% confidence interval (CI) 0.76 to 1.26). Annual rates for heart failure death or transplantation and stroke related death were 0.55% (95% CI 0.37% to 0.78%) and 0.07% (95% CI 0.02% to 0.19%), respectively. When studies published within the last 10 years of the study period were compared with earlier reports, the size of individual study cohorts was larger (309 (240.6) v 136.5 (98.8), p = 0.058) and the proportion with severe functional limitation NYHA class III/IV lower (12.4% v 24.8%, p < 0.0001), and fewer patients underwent septal myotomy-myectomy (5.2% v 18.7%, p < 0.0001). Published sudden death rates over the last 10 years were lower than previously published figures (median 1.0% (range 0.1-1.7) v 2.0% (0-3.5)). CONCLUSION: Published survival rates in HCM cohorts have improved progressively over the past 40 years. In the modern era the prevalence of disease related complications is similar in all reporting centres.