Despite the ability of whole genome sequencing to diagnose patients with rare genetic disease, the technology still leaves many patients without a clear diagnosis. Rady Children’s Institute for Genomic Medicine, which has innovated the use of rapid whole genome sequencing in the neonatal and pediatric ICU, is now working to diagnosed patients left undiagnosed by whole genome sequencing with long-read whole genome sequencing through a collaboration with Pacific Biosciences. We spoke to Matthew Bainbridge, principal investigator and associate director of clinical genomics at Rady Children’s Institute for Genomic Medicine, about the collaboration, how long-read sequencing differs from traditional whole genome sequencing, and why this is helping to find answers for undiagnosed patients with rare genetic diseases.