AUTHOR=Marouane Abderrahim , Neveling Kornelia , Deden A. Chantal , van den Heuvel Simone , Zafeiropoulou Dimitra , Castelein Steven , van de Veerdonk Frank , Koolen David A. , Simons Annet , Rodenburg Richard , Westra Dineke , Mensenkamp Arjen R. , de Leeuw Nicole , Ligtenberg Marjolijn , Matthijsse Rene , Pfundt Rolph , Kamsteeg Erik Jan , Brunner Han G. , Gilissen Christian , Feenstra Ilse , de Boode Willem P. , Yntema Helger G. , van Zelst-Stams Wendy A. G. , Nelen Marcel , Vissers Lisenka E. L. M. TITLE=Lessons learned from rapid exome sequencing for 575 critically ill patients across the broad spectrum of rare disease JOURNAL=Frontiers in Genetics VOLUME=14 YEAR=2024 URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2023.1304520 DOI=10.3389/fgene.2023.1304520 ISSN=1664-8021 ABSTRACT=

Introduction: Rapid exome sequencing (rES) has become the first-choice genetic test for critically ill patients, mostly neonates, young infants, or fetuses in prenatal care, in time-sensitive situations and when it is expected that the genetic test result may guide clinical decision making. The implementation of rES has revolutionized medicine by enabling timely identification of genetic causes for various rare diseases. The utilization of rES has increasingly been recognized as an essential diagnostic tool for the identification of complex and undiagnosed genetic disorders.

Methods: We conducted a retrospective evaluation of our experiences with rES performed on 575 critically ill patients from various age groups (prenatal to adulthood), over a four-year period (2016–2019). These patients presented with a wide spectrum of rare diseases, including but not limited to neurological disorders, severe combined immune deficiency, and cancer.

Results: During the study period, there was a significant increase in rES referrals, with a rise from a total of two referrals in Q1-2016 to 10 referrals per week in Q4-2019. The median turnaround time (TAT) decreased from 17 to 11 days in the period 2016–2019, with an overall median TAT of 11 days (IQR 8–15 days). The overall diagnostic yield for this cohort was 30.4%, and did not significantly differ between the different age groups (e.g. adults 22.2% vs children 31.0%; p-value 0.35). However, variability in yield was observed between clinical entities: craniofacial anomalies yielded 58.3%, while for three clinical entities (severe combined immune deficiency, aneurysm, and hypogonadotropic hypogonadism) no diagnoses were obtained.

Discussion: Importantly, whereas clinical significance is often only attributed to a conclusive diagnosis, we also observed impact on clinical decision-making for individuals in whom no genetic diagnosis was established. Hence, our experience shows that rES has an important role for patients of all ages and across the broad spectrum of rare diseases to impact clinical outcomes.