Genetic heterogeneity of left ventricular noncompaction cardiomyopathy

Isolated noncompaction of the ventricular myocardium (INVM), sometimes referred to as spongy myocardium, is a rare, congenital, and also acquired cardiomyopathy. It appears to divide the presentation into neonatal, childhood, and adult forms, of which spongy myocardium and systolic dysfunction is the commonality. The disorder is characterized by a left ventricular (LV) hypertrophy with deep trabeculations, and with diminished systolic function with or without associated LV dilation. In half or more of the cases, the right ventricle is also affected. The sporadic type, however, in some patients, may be due to chromosomal abnormalities and the occurrence of familial incidence. Isolated noncompaction of the LV myocardium in the majority of adult patients is an autosomal dominant disorder. The familial and X-linked disorders have been described by various authors. We describe here the genetic background of this disorder: some of the most mutated genes that are responsible for the disease are (G(4.5) [tafazzin gene]: alpha-dystrobrevin gene [DTNA]; FKBP-12 gene; lamin A/C gene; Cypher/ZASP [LIM, LDB3] gene); and some genotype-phenotype correlations, (i.e., Becker muscular dystrophy, Emery-Dreifuss muscular dystrophy, or Barth syndrome [BTHS]) based on the literature review.