Approach to inborn errors of metabolism presenting in the neonate

Inborn errors of metabolism (IEM) are an important cause of acute illness in newborns. Presentation may mimic common neonatal conditions such as sepsis. Prompt detection requires a high index of suspicion and the early measurement of biochemical markers such as blood ammonia. Diagnosis is important not only for treatment but also for genetic counselling. Guidelines for diagnosis and early management of IEM presenting in the neonatal period are described.