Abstracts

Rationale: Genetic testing for people with epilepsy has identified a molecular etiology in up to 40% of cases, becoming an integral tool in the diagnostic workup. However, limited quantitative and qualitative assessments have been performed to understand how genetic information is used by clinicians to guide management of patients with epilepsy and the impact this may have on outcomes. Seizure management has major implications for quality of life and overall healthcare costs. Previous studies demonstrate considerably reduced healthcare costs for individuals with good versus poor seizure control, due to decreased hospitalizations and emergency department visits. We investigated changes in clinical management and patient outcomes after identification of a diagnostic genetic finding.

Methods: Clinicians caring for patients with epilepsy in whom a diagnostic genetic finding had been identified were contacted to participate in a case report collection study. Information analyzed included genetic diagnosis, provider-reported changes in clinical management, and impact on patient outcomes including seizure frequency and other health measures.

Results: Between May-November 2020, a survey was sent to 1,567 ordering clinicians representing 3,572 patients with diagnostic, likely pathogenic or pathogenic variants in an epilepsy gene. There were 170 providers who completed case reports (10.8% response rate) and the final study cohort included clinical information for 429 (12.0%) patients. Clinical specialties for responding providers included genetics (22.4%), pediatric neurology (17.1%), neurology (15.3%), epilepsy (7.6%), internal medicine (0.6%), or a combination of specialties (37.1%). In 49.9% of cases (n=214), the diagnostic genetic finding led to changes in clinical management. In most cases (81.3%), clinical management changed within 3 months of receiving the genetic result. The most common changes involved antiseizure medication adjustments (51.5%, n=191) including starting a new medication (35.6%, n=132), stopping a medication (11.6%, n= 43), or changing a dose (4.3%, n=16). Other changes in management included referral to a specialist (13.5%) and monitoring for extra-neurological disease (12.9%). Outcome data were reported for 172 (40.0%) patients. Three-quarters of individuals experienced positive clinical outcomes, including 65% with reduced or no seizures after treatment changes and 17.8% reporting other clinical benefits (i.e., improved behavior, development, academics, movement issues), and 5% experienced decreased medication side-effects. In adult patients, which represented a small subset of this cohort, a similar trend in improved and/or controlled seizures after treatment modification was also observed (58%, n=7/12).

Conclusions: This study indicates that genetic testing led to changes in clinical management. Importantly, these changes can lead to improved seizure control in many patients with diagnostic findings. These results support growing evidence that genetic testing can improve health outcomes, which could also reduce healthcare costs.

Funding: Please list any funding that was received in support of this abstract.: N/A.