Many of these phenotypic changes were observed basally in the dn-c-kit-Tg model, including LV hypertrophy (increased LVW/TL ratio, increased LVED wall thickness) with decreased LV cavity size (decreased LV internal chamber radius) and CM hypertrophy (increased CM area) in the absence of an increase in afterload (LVSP unchanged) as well as activation of the fetal gene program (enhanced Nppa, Nppb and Myh7 mRNA levels). The gene discussed is NPPB; the disease is cutaneous mastocytosis.