BackgroundInborn errors of metabolism are on the differential for patients presenting with a cyclic vomiting syndrome phenotype. Classes of disorders to consider include: mitochondrial disorders, fatty acid oxidation disorders, urea cycle defects, organic acidurias, and acute intermittent porphyria.AimThis article reviews the metabolic differential diagnosis and approach to screening for inborn errors in children and adults presenting with a cyclic or recurrent vomiting phenotype.ConclusionCyclic vomiting syndrome is thought to be an episodic syndrome that may be associated with migraine. It is a diagnosis of exclusion. Inborn errors of metabolism should be considered in the patient presenting with a recurrent vomiting phenotype. Mitochondrial dysfunction may play a role in cyclic vomiting syndrome, and true mitochondrial disorders can present with a true cyclic vomiting phenotype
