Ultra-rapid whole genome nanopore sequencing in a critical care setting

Andrew Carroll
Ankit Sethia
Benedict Paten
Christopher Wright
Courtney J. Wusthoff
Daniel R Garalde
Dianna G. Fisk
Elizabeth Spiteri
Euan Ashley
Fritz J. Sedlazeck
Gunjan Baid
Henry Chubb
Jeffrey W Christle
Jeffrey W. Christle
John E. Gorzynski
Jonathan A Bernstein
Joseph Guillory
Joshua W. Knowles
Katherine Xiong
Kishwar Shafin
Kyla Dunn
Marco Perez
Maria Nattestad
Maura RZ Ruzhnikov
Megan E. Grove
Mehrzad Samadi
Michael Ma
Miten Jain
Scott R. Ceresnak
Sneha D. Goenka
Tanner D. Jensen
Tia Moscarello
Tong Zhu
Trevor Pesout
New England Journal of Medicine (2022)

Abstract

Background

Genetic disease is a major contributor to critical care hospitalization, especially in younger patients. While early genetic diagnosis can guide clinical management, the turnaround time for whole genome based diagnostic testing has traditionally been measured in months. Recent programs in neonatal populations have reduced turnaround time into the range of days and shown that rapid genetic diagnosis enhances patient care and reduces healthcare costs. Yet, most decisions in critical care need to be made on hourly timescales.

Methods

We developed a whole genome sequencing approach designed to provide a genetic diagnosis within hours. Optimized highly parallel nanopore sequencing was coupled to a high-performance cloud compute system to implement near real-time basecalling and alignment followed by accelerated central and graphics processor unit variant calling. A custom scheme for variant prioritization took only minutes to rank variants most likely to be deleterious allowing efficient manual review and classification according to American College of Medical Genetics and Genomics guidelines.

Results
We performed whole genome sequencing on 12 patients from the critical care units of Stanford hospitals. In 10 cases, the pipeline produced diagnostic results faster than all previously published clinical genome analyses. Per patient, DNA extraction, library preparation, and nanopore sequencing across 48 flow cells generated 173–236 GigaBases of sequencing data in as little as 1:50 hours. After optimization, the average turnaround time was 7:58 hours (range 7:18–9:0 hours). A pathogenic or likely pathogenic variant was identified in five out of 12 patients (42%). After Sanger or short read sequencing confirmation in a CLIA-approved laboratory, this validated diagnosis altered clinical management in every case.

Conclusions

We developed an approach to make a genetic diagnosis from whole genome sequencing in hours, returning actionable, cost-saving diagnostic information on critical care timescales.

Research Areas