Cases of sudden unexpected infant death (SUID) leave many families devastated, especially in those without an identified cause of death. Here, we describe the case of an apparently healthy 15-day-old infant who died suddenly and unexpectedly. Through whole-exome sequencing, the infant was posthumously found to have 2 mutations in the CLCNKB gene, leading to a molecular diagnosis of Bartter syndrome type III, the likely cause of death. This case illustrates the potential utility of exome sequencing in cases of SUID to suggest a diagnosis, with important implications for families, allowing them to come to closure over the cause of death, informing their future reproductive decisions, and minimizing the risk of recurrence.
Keywords: Bartter syndrome; CLCNKB; SIDS; SUID; whole-exome sequencing.