Out of these mutations patients with transmembrane protein 70 (TMEM70) mutations most often present with neonatal onset of elevated plasma lactate levels, 3-methylglutaconic aciduria (3-MGA), cardiomyopathy, facial dysmorphism, and psychomotor and mental retardation [6, 7] and emerged to be clinically well characterized since the gene description in 2008. Here, TMEM70 is linked to cardiomyopathy.