Genetic Testing and Challenges in a Level IV Midwestern NICU: Who, What, When, and Then?

This study aimed to examine genetic testing strategies and their impact on redirection of care and on reducing prognostic uncertainty in the NICU.

This is a retrospective cohort study from 2020 to 2021.

Out of 774 NICU infants, 133 (17%) received genetic testing, most commonly whole exome sequencing. A genetic diagnosis was achieved in 33% of cases. About 70% of infants who received genetic testing were not critically ill. Decisions about redirection of care were associated with presence of critical illness and not presence of genetic diagnosis. Many rare diagnoses were made through genetic testing in the NICU, but except for certain chromosomal anomalies, these diagnoses had wide variability in reported phenotypic presentations.

Genetic testing achieves a unifying diagnosis for many NICU patients, yet many of these diagnoses have variable clinical presentations. Redirection of care in the NICU is reliant on clinical illness severity more often than achievement of a genetic diagnosis. Clinicians must provide meaningful interpretation of genetic test results to families and be prepared to confront uncertainty even after pathogenic variants are found.

· One-fifth of NICU patients received genetic testing.. · Often, these patients were not critically ill.. · Genetic diagnosis was made in a third of patients tested.. · Most diagnoses had variable phenotypic presentations.. · Redirection of care was associated with critical illness..