STX4 and systemic primary carnitine deficiency disease: Energy, Nutrition and Homeostasis6 Genes-phosphatidylserine synthase 2-glycerol kinase 2-NADH dehydrogenase (ubiquinone) Fe-S protein 4, 18 kDa (NADH-coenzyme Q reductase)(Leigh syndrome [49])-NAD(P)H dehydrogenase, quinone 1(childhood acute lymphoblastic leukemia [41])-solute carrier family 22 (organic cation/carnitine transporter), member 5(primary carnitine deficiency [75])-syntaxin 4