Diagnostic and service impact of genomic testing technologies in a neonatal intensive care unit.

AIM: To investigate the diagnostic and service impact of chromosomal microarray and whole exome sequencing (WES) in a neonatal intensive care unit (NICU).

METHODS: This was a retrospective medical record review of NICU patients referred for genetics consultation at three time points over a 9-year period at a single centre to determine referral indications, genetic consultation outcomes and time to diagnosis.

RESULTS: The number of NICU patients referred for genetics consultation increased from 44 in 2007 to 95 in 2015. The proportion of NICU patients suspected of having a genetic condition following clinical geneticist assessment remained stable, averaging 5.3% of all admissions. The proportion of patients receiving a confirmed diagnosis rose from 21% in 2007 to 53% in 2015, with a shift from primarily chromosomal abnormalities to a broad range of monogenic disorders, increasingly diagnosed by WES as a first-tier test. The average age at diagnosis in 2015 was 19 days (range 12-38 days) for chromosomal abnormalities and 138 days (range 10-309 days) for monogenic conditions.

CONCLUSIONS: The adoption of new genetic technologies at our centre has increased the proportion of patients receiving a confirmed genetic diagnosis. This study provides important benchmark data to measure further improvements as turn-around times for genomic testing decrease.