Background-Left ventricular noncompaction constitutes a primary cardiomyopathy characterized by a severely thickened, 2-layered myocardium, numerous prominent trabeculations, and deep intertrabecular recesses. The genetic basis of this cardiomyopathy is still largely unresolved. We speculated that mutations in sarcomere protein genes known to cause hypertrophic cardiomyopathy and dilated cardiomyopathy may be associated with left ventricular noncompaction. Methods and Results-Mutational analysis in a cohort of 63 unrelated adult probands with left ventricular noncompaction and no other congenital heart anomalies was performed by denaturing high-performance liquid chromatography analysis and direct DNA sequencing of 6 genes encoding sarcomere proteins. Heterozygous mutations were identified in 11 of 63 samples in genes encoding ␤-myosin heavy chain (MYH7), ␣-cardiac actin (ACTC), and cardiac troponin T (TNNT2). Nine distinct mutations, 7 of them in MYH7, 1 in ACTC, and 1 in TNNT2, were found. Clinical evaluations demonstrated familial disease in 6 of 11 probands with sarcomere gene mutations. MYH7 mutations segregated with the disease in 4 autosomal dominant LVNC kindreds. Six of the MYH7 mutations were novel, and 1 encodes a splice-site mutation, a relatively unique finding for MYH7 mutations. Modified residues in ␤-myosin heavy chain were located mainly within the ATP binding site. Conclusions-We

Deletion 1p36 syndrome is recognized as the most common terminal deletion syndrome. Here, we describe the loss of a gene within the deletion that is responsible for the cardiomyopathy associated with monosomy 1p36, and we confirm its role in nonsyndromic left ventricular noncompaction cardiomyopathy (LVNC) and dilated cardiomyopathy (DCM). With our own data and publically available data from array comparative genomic hybridization (aCGH), we identified a minimal deletion for the cardiomyopathy associated with 1p36del syndrome that included only the terminal 14 exons of the transcription factor PRDM16 (PR domain containing 16), a gene that had previously been shown to direct brown fat determination and differentiation. Resequencing of PRDM16 in a cohort of 75 nonsyndromic individuals with LVNC detected three mutations, including one truncation mutant, one frameshift null mutation, and a single missense mutant. In addition, in a series of cardiac biopsies from 131 individuals with DCM, we found 5 individuals with 4 previously unreported nonsynonymous variants in the coding region of PRDM16. None of the PRDM16 mutations identified were observed in more than 6,400 controls. PRDM16 has not previously been associated with cardiac disease but is localized in the nuclei of cardiomyocytes throughout murine and human development and in the adult heart. Modeling of PRDM16 haploinsufficiency and a human truncation mutant in zebrafish resulted in both contractile dysfunction and partial uncoupling of cardiomyocytes and also revealed evidence of impaired cardiomyocyte proliferative capacity. In conclusion, mutation of PRDM16 causes the cardiomyopathy in 1p36 deletion syndrome as well as a proportion of nonsyndromic LVNC and DCM.

Background-Left ventricular noncompaction of the myocardium (LVNC) has been recognized as a cardiomyopathy with a genetic etiology. Mutations in genes encoding sarcomere proteins were shown to be associated with LVNC. We evaluated the potential clinical impact of genetic analysis of sarcomere genes in patients with LVNC. Methods and Results-We identified 5 mutations in cardiac myosin-binding protein C (MYBPC3) and 2 mutations in ␣-tropomyosin (TPM1) in a cohort of unrelated adult probands with isolated LVNC. The mutations in MYBPC3 and TPM1 and in 6 other previously reported sarcomere genes in this cohort resulted in a total of 18 (29%) heterozygous mutations in 63 probands. ␤-myosin heavy chain (MYH7) was the most prevalent disease gene and accounts for 13% of cases, followed by MYBPC3 (8%). Comparing sarcomere mutation-positive and mutation-negative LVNC probands showed no significant differences in terms of average age, myocardial function, and presence of heart failure or tachyarrhythmias at initial presentation or at follow-up. Familial disease was found in 16 probands of whom 8 were sarcomere mutation positive. Nonpenetrance was detected in 2 of 8 mutation-positive families with LVNC. Conclusions-Mutations

Many pregnant women with heart disease have increased BNP levels during pregnancy. Incorporating serial BNP levels in into clinical practice can be helpful, specifically in adjudicating suspected adverse cardiac events during pregnancy.

INTRODUCTION: Left ventricular non-compaction cardiomyopathy (LVNC) is a rare cardiomyopathy, originally described as an isolated disease without other structural cardiac abnormalities. The aim of this study was to explore the prevalence of LVNC among adults with different types of congenital heart disease. METHODS: From our databases we identified adults with congenital heart disease who fulfilled diagnostic criteria for LVNC. We report frequencies of associated congenital cardiac defects and the prevalence of LVNC among patients with different congenital heart defects. RESULTS: From a total of 202 patients with LVNC, 24 patients (12%; mean age 32±11years, 19 males) had additional congenital cardiac defects. Associated defects were left ventricular outflow tract abnormalities in 11 patients (46%), including 7 uni-or bicuspid aortic valves; two aortic coarctations; one diffuse aortic hypoplasia and one subaortic stenosis, Ebstein anomaly in 6 patients (25%), tetralogy of Fallot in two (8%), and double outlet right ventricle in one patient (4%). In our cohort, the prevalence of LVNC was highest among patients with Ebstein anomaly (6/40, 15%), followed by aortic coarctation (2/60, 3%), tetralogy of Fallot (3/129, 2%) and uni-or bicuspid aortic valves (7/963, 1%). CONCLUSION: In adults, various forms of congenital heart disease are associated with LVNC, particularly stenotic lesions of the left ventricular outflow tract, Ebstein anomaly, and tetralogy of Fallot. In the future, studying these patients in more depth may provide a better understanding of the interplay between genetic and hemodynamic factors that lead to the phenotype of LVNC.

Although most adults after ASO are well, and few have residual defects, there are subgroups, particularly those who needed further cardiac intervention in childhood, who are at higher risk for ventricular and valve dysfunction and arrhythmias.

Mortality in pregnant women with AS, including those with severe AS, appears to be close to zero in the current era. Symptomatic and severe AS does, however, carry a substantial risk of heart failure and is associated with high rates of hospitalization for cardiac reasons, although heart failure can nearly always be managed medically. The results highlight the importance of appropriate pre-conceptional patient evaluation and counseling.

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