SLC25A20 and hyperinsulinemic hypoglycemia, familial, 4: Echocardiograms performed in 11 patients disclosed structural changes in five: coarctation of the aorta in a patient with multiple oxidative phosphorylation defects (complexes IV-V-II+IV); pericardial effusion in a newborn with carnitine-acylcarnitine translocase deficiency; mitral and aortic insufficiency in one case of methylmalonic aciduria; isolated mitral insufficiency in one patient with classic galactosemia and left ventricular hypertrophy in a case with maple syrup urine disease.