Early Genetic Testing in Pediatric Epilepsy: Diagnostic and Cost Implications.

The identification of numerous genetically based epilepsies has resulted in the widespread use of genetic testing to inform epilepsy etiology. Our study aims to investigate whether a difference exists in the diagnostic evaluation and healthcare related cost expenditures of pediatric patients with epilepsy of unknown etiology who receive a genetic diagnosis through multigene epilepsy panel (MEP) testing and comparing those who underwent early (EGT) versus late genetic testing (LGT). Testing was defined as early (less than 1 year), or late (more than 1 year), following clinical epilepsy diagnosis. A retrospective chart review of pediatric individuals (1-17 years) with epilepsy of unknown etiology who underwent multigene epilepsy panel (MEP) testing identified 28 of 226 (12%) individuals with a pathogenic epilepsy variant [EGT n=8 (29%); LGT n=20 (71%)]. The average time from clinical epilepsy diagnosis to genetic diagnosis was 0.25 years (EGT), compared to 7.1 years (LGT). The EGT cohort underwent fewer metabolic tests [EGT n=0 (0%); LGT n=16 (80%) (P<0.01)] and invasive procedures [EGT n=0 (0%); LGT n=5 (25%) (P=0.06)]. Clinical management changes implemented due to genetic diagnosis occurred in 10 (36%) patients [EGT n=2 (25%); LGT n=8 (40%) (P=0.76)]. Early genetic testing with a MEP in pediatric patients with epilepsy of unknown etiology who receive a genetic diagnosis is associated with fewer non-diagnostic tests and invasive procedures and reduced estimated overall healthcare-related costs.