ABSTRACT
Left ventricular hypertrophy (LVH), reflecting a growth in individual myocyte size rather than an increase in cell number (hyperplasia), is one of the most powerful predictors of cardiac death. Most commonly, LVH is produced as a secondary consequence of increased cardiac load; in that setting the extent of hypertrophy is influenced by multiple susceptibility genes, and LVH functions as a classical polygenic quantitative trait. However, cardiac hypertrophy can also be triggered by inherited single gene disorders in the absence of other cardiac or systemic disease. Genetic analyses have the power to identify previously unknown pathogenic pathways causing LVH, because such analyses can be applied systematically without reliance on existing assumptions regarding etiology. Accordingly, monogenic disorders that result in cardiac hypertrophy have been an important area of study, with ramifications that extend beyond the direct clinical impact of these relatively uncommon conditions.
