An inherited metabolic disorder characterized by the body's inability to break down proteins and fats to produce energy. It is a disorder of fatty acid, amino acid, and choline metabolism and has an autosomal recessive inheritance pattern. It has_material_basis_in mutations in the ETFA, ETFB and ETFDH genes. It presents three clinical phenotypes: a neonatal-onset form with congenital anomalies (type I), a neonatal-onset form without congenital anomalies (type II), and a late-onset form (type III). The neonatal-onset forms are usually fatal.