Not so rare: Errors of metabolism during the neonatal period

During the neonatal period, the diagnosis of an error of metabolism (EM) was once thought to portend a poor prognosis or lethality. Over the past two decades, the prognosis of many EMs has changed. The critical aspect of the metabolic evaluation in a sick newborn is to rapidly identify whether there may be a metabolic problem. If there is a metabolic problem, the goal is to minimize the sequelae of the specific disorder. This review will explore how to approach and evaluate a newborn suspected of having an EM. A discussion of clinical and laboratory findings that often accompany EM will be included.