Study Hints at Clinical Lab’s Future Role in Investigating Sudden Unexplained Death in Children
UW Medicine and Seattle Children’s launch long-read sequencing research to uncover genetic factors, setting new standards for pediatric genomic testing.
The Sudden Unexplained Death in Childhood (SUDC) Foundation has awarded funding to a team at UW Medicine and Seattle Children’s Hospital to use PacBio HiFi long-read sequencing as a first-line tool to investigate cases of SUDC.
The study represents a critical step in both research and clinical laboratory practice. Applying long-read sequencing as a first-tier assay can streamline workflows, particularly when working with challenging samples such as post-mortem tissue or dried blood spots. Laboratories involved will need to combine advanced sequencing with robust bioinformatics pipelines, accurate variant interpretation, and integration of parental genomes to provide clinically relevant results.
The study, led by Danny E. Miller, MD, PhD, assistant professor of pediatrics and laboratory medicine and pathology at the University of Washington, and Alexandra Keefe, MD, PhD, assistant professor of pediatrics at UW Medicine, will sequence 200 family trios—a child and their parents—aiming to uncover genetic factors that may contribute to these sudden, unexplained deaths.
PacBio’s Revio system with SPRQ-Nx chemistry will be used to generate highly accurate long-read genomes, allowing researchers to detect complex structural variants and tandem repeats that traditional sequencing may miss. By including parental data, the team hopes to distinguish inherited variants from spontaneous mutations, increasing the likelihood of actionable findings for families.
Long-Read Sequencing Advances SUDC Investigations
“Selecting HiFi sequencing as our first-line whole-genome assay allows us to search for answers with the accuracy and breadth these families deserve,” said Miller. “By starting with long reads and incorporating parental data, we can resolve difficult variants, phase them accurately, and provide guidance relevant to SUDC.”
The SUDC Foundation currently assists over 1,000 families in more than 20 countries. The organization emphasizes the importance of comprehensive investigations for sudden child deaths, including genetic testing, DNA banking, and family screening when appropriate.
“Families affected by SUDC face unimaginable loss,” said Julia Burgess, president of the SUDC Foundation. “Funding this project reflects our commitment to advancing research that brings clarity, guidance, and hope to grieving families nationwide.”
Beyond supporting families, the research could establish a model for how cutting-edge genomic testing is incorporated into clinical investigations of sudden childhood deaths. The team plans to implement a tiered genomic approach for cases with suspected genetic causes, beginning with trio-based exome and low-pass whole-genome sequencing, followed by reflexive long-read sequencing when necessary.
“This project has the potential not only to provide answers to families but also to transform standards for genetic investigation in pediatric sudden death,” said Keefe. “It highlights the essential role laboratories play in turning advanced genomic technologies into actionable clinical knowledge.” (Photo credit: UW Medicine)
The SUDC Foundation expects the study, funded at $328,133 over four years, to generate data that supports broader adoption of long-read sequencing in pediatric genomics and enhance understanding of the genetic underpinnings of SUDC.
For clinical laboratory professionals, this initiative underscores the growing expectation that advanced genomic technologies—particularly long-read whole-genome sequencing and trio analysis—will play a larger role in investigating unexplained pediatric deaths. As these tools move toward first-line use, labs must be prepared to support complex variant detection, robust bioinformatics interpretation, and collaboration with clinicians and medical examiners, positioning the laboratory at the center of efforts to deliver clearer answers for families.
—Janette Wider
