Therefore, we measured the following four cysteine/cysteamine conjugates from valine metabolites: S-(2-carboxypropyl) cysteine (SCPC) and S-(2-carboxypropyl) cysteamine (SCPCM) from methacrylyl-CoA and S-(2-carboxyethyl)cysteine (SCEC) and S-(2-carboxyethyl)cysteamine (SCECM) from acryloyl-CoA in urine and serum from six patients (four new patients and two patients reported with ECHS1 deficiency [14]). The gene discussed is ECHS1; the disease is hyperinsulinemic hypoglycemia, familial, 4.