Identification of Decreased Butyrylcholinesterase in Sudden Infant Death Syndrome Is, at Best, a First Step Toward Preventive Screening.

Abstract

The identification of a biomarker associated with increased risk of sudden infant death syndrome (SIDS), as described by Harrington et al. (1) is an exciting yet cautionary tale combining the incremental progress of scientific research and the hazards of media hype. The authors propose an association of decreased butyrylcholinesterase (BChE) activity levels in newborn screening (NBS) dried blood spots collected from infants who died of SIDS compared to surviving controls. This association was not seen in a cohort of non-SIDS deaths when compared to surviving controls. The authors theorize that decreased BChE activity is a marker for autonomic dysfunction, a vulnerability previously suspected to be implicated in the triple risk model for SIDS (2). While considerable decreases in SIDS deaths have been accomplished through NBS programs and safe sleep education, a significant number of infants still die of SIDS, and other promising diagnostic approaches (e.g., genomic analyses) are so far only pursued in the research environment (3). Harringtons study had a robust design with well-defined cases and controls. Utilizing NBS dried blood samples recognizes the need for future screening to work within existing systems for sample collection and availability, and takes advantage of preserved samples for the potential benefit of babies and families in the future. This study was made possible in part by the recognition that stored NBS blood samples can provide valuable information for future expansion of NBS panels. The rarity of most conditions targeted for NBS precludes prospective case identification. Regions that destroy samples after short retention periods are limiting opportunities for improvement and expansion of screening programs, as well as for families to obtain critical information from these samples.