Figure 1From: Clinical utility of genetic tests for inherited hypertrophic and dilated cardiomyopathies Single gene disorders or complex traits. A single rare mutation can fully account for a Mendelian disease; clinical variability can be, however, observed even for determined monogenic disease, and this variability may itself involve genetic factors, the so-called modifier genes. In contrast to monogenic traits, complex traits have many contributing genes and non-genetic influences.Back to article page