The Metabolic Autopsy Comes of Age

Abstract

The concept of sudden infant death syndrome (SIDS) was introduced in the early 1970s in an attempt to categorize death in a group of infants who died suddenly and unexpectedly and in whom a thorough postmortem investigation failed to provide a credible diagnosis (1) The diagnosis of SIDS or sudden unexpected death in early life, which encompasses a greater number of cases, remains the largest single cause of death in children in the industrialized nations. The reported frequency is ∼1:1000 live births, a figure that represents 25% of all deaths in the first year of life. In the beginning, the first clue that a subset of these infants may have a metabolic derangement came from the pioneering autopsy studies of Professor John Emery (2) By investigating 200 infants who were initially given the diagnosis of SIDS, Emery recognized that 5% of them had diffuse fatty change of the liver. It was suggested that these children had been in some state of metabolic “poisoning” or had suffered an acute metabolic decompensation such as that seen in Reye syndrome. The first factual diagnosis of an inborn error of metabolism in an infant initially classified as SIDS was made in 1984 (3) A 14-month-old infant who died suddenly after a 48-h history of nonspecific malaise, was found at autopsy to have diffuse fatty changes to viscera, and was eventually …