Noncompaction of the left ventricle: primary cardiomyopathy with an elusive genetic etiology.
OBJECTIVE
Noncompaction of the left ventricle is a descriptive anatomical term and recently recognized primary cardiomyopathy. Cardiac imaging now allows for prompt detection. The specific etiology remains poorly understood, however, and the major genetic determinants are unknown. This review describes recent data showing the genetic heterogeneity and overlap with other cardiomyopathies. Understanding the genetics may depend on clarifying the distinctive diagnostic features and investigating the contribution of all known cardiomyopathy-causing genes with overlapping morphology.


RESULTS
Adding to the known genes (TAZ, DTNA, LDB3 and LMNA), recent work has identified SCN5A, MYH7 and MYBPC3 as associated loci. LDB3 may also be a genetic modifier. Case reports and linkage studies suggest additional loci at 1p36, 1q43 and 11p15. Aside from Barth syndrome, other genetic and metabolic syndromes with noncompaction have been described. Despite this, large studies have failed to identify the etiology in the majority of patients.


CONCLUSIONS
Despite advances in detection, comprehensive clinical, pathological, genetic, and family studies are necessary to define the phenotypic overlap with other cardiomyopathies. Without a more precise understanding of its etiology, the answers to the questions regarding the clinical relevance and management of patients with noncompaction of the left ventricle will remain elusive.
Zaragoza
Michael V
MV
Center for Molecular and Mitochondrial Medicine and Genetics and the Department of Pediatrics, Division of Genetics and Metabolism, University of California, Irvine, California 92697-3940, USA. mzaragoz@uci.edu
Arbustini
Eloisa
E
Narula
Jagat
J
D000217:Acyltransferases; D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics; D009202:Cardiomyopathies / Q000235:genetics* / Q000473:pathology; D002648:Child; D018740:Genetic Heterogeneity; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000235:genetics; D060588:LIM Domain Proteins; D009468:Neuromuscular Diseases / Q000235:genetics; D010641:Phenotype; D011506:Proteins / Q000235:genetics; D019837:Ryanodine Receptor Calcium Release Channel / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
D048868:Adaptor Proteins, Signal Transducing; C120696:LDB3 protein, human; D060588:LIM Domain Proteins; D011506:Proteins; D019837:Ryanodine Receptor Calcium Release Channel; D014157:Transcription Factors; D000217:Acyltransferases; C108675:TAFAZZIN protein, human