Rethinking what constitutes a diagnosis in the genomics era: a critical illness perspective

Purpose of review The purpose of this review is to highlight the significant advances in the testing, interpretation, and diagnosis of genetic abnormalities in critically ill children and to emphasize that pediatric intensivists are uniquely positioned to search for genetic diagnoses in these patients. Recent findings Ten years following the first clinical diagnosis made through whole exome sequencing, we remain in the dark about the function of roughly 75% of our genes. However, steady advancements in molecular techniques, particularly next-generation sequencing, have spurred a rapid expansion of our understanding of the genetic underpinnings of severe congenital diseases. This has resulted in not only improved clinical diagnostics but also a greater availability of research programs actively investigating rare, undiagnosed diseases. In this background, the scarcity of clinical geneticists compels nongeneticists to familiarize themselves with the types of patients that could benefit from genetic testing, interpretations of test results as well as the available resources for these patients. Summary When caring for seriously ill children, critical care pediatricians should actively seek the possibility of an underlying genetic cause for their patients' conditions. This is true even in instances when a child has a descriptive diagnosis without a clear underlying molecular genetic mechanism. By promoting such diagnostics, in both clinical and research settings, pediatric intensivists can advance the care of their patients, improve the quality of information provided to families, and contribute to the knowledge of broad fields in medicine.