MECR and nervous system disorder: Mitochondrial Enoyl CoA Reductase Protein-Associated Neurodegeneration (MEPAN) syndrome, also known as mitochondrial enoyl-CoA/ACP (acyl carrier protein) reductase (MECR)-related neurologic disorder, is an extremely rare pediatric metabolic condition caused by autosomal recessive mutations in the MECR gene (1).