I am aware of the diagnosis in this case. This newborn boy, born prematurely at a gestational age of 29 weeks, had a relatively typical course in the NICU until suddenly, on his sixth day of life, progressive multiorgan system failure developed, and he died early on his seventh day of life. For diagnostic possibilities, I considered four categories of neonatal disorders: inborn errors of metabolism, respiratory failure, cardiomyopathy, and bacterial or viral sepsis.