Early Genetic Testing May Benefit Patients With Infantile-Onset Epilepsies

The following article is part of conference coverage from the American Epilepsy Society’s Annual Meeting in New Orleans, LA. The Neurology Advisor’s staff will be reporting breaking news associated with research conducted by leading experts in neurology. Check back for the latest news from AES 2018.

NEW ORLEANS — Individuals with epilepsy who receive an early genetic diagnosis may benefit from more precise medical treatment, accurate counseling, and guidance toward applicable clinical trials. This research was presented at the 72nd Annual Meeting of the American Epilepsy Society, held November 30 to December 4, 2018, in New Orleans, LA.

This retrospective study included 2833 participants with epilepsy, all of whom underwent genetic testing for genes indicating infantile-onset epilepsy. Among these participants, 23% (n=664) were positively diagnosed, with 39% (n=256) of these cases composed of pathogenic/likely pathogenic variants in the CDKL5, PRRT2, KCNQ2, and STXBP1 genes.

The mean age at molecular diagnosis varied by gene (CDKL5, 3.48 years [0.25 to 22.6]; PRRT2, 0.90 [0.14 to 5.4]; STXBP1, 4.07 years [0.06 to 27.6]; KCNQ2, 1.63 years [0.05 to 39.5]).

Testing was performed between 2012 and 2017, during which time patients increased by a factor of 3. While mean age at genetic diagnosis for CDKL5, PRRT2, and KCNQ2 did not vary significantly over the course of the study, it did decrease from 7.5 years to 0.5 years for STXBP1 pathogenic variants.

Testing was administered in a laboratory for clinical diagnosis, which was performed using exon-level array comparative genomic hybridization and Next Generation sequencing. The age of all participants, including those with genetic variants among genes of interest, was recorded at time of genetic testing diagnosis.

The study researchers concluded that “[an] early molecular diagnosis may benefit patients with epilepsy by ending the lengthy and expensive diagnostic odyssey, enabling accurate genetic counseling about recurrence risks, and allowing for precision medicine or participation in clinical trials in some cases. …[Although] genetic testing panels for infantile-onset epilepsy are ordered more frequently in recent years, testing is often pursued months to years after the initial onset of seizures and is often not incorporated into the initial evaluation of new-onset infantile seizures.”

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Reference

Butler E, Richard G, Lindy A, McKnight D. Age at genetic diagnosis for patients with infantile-onset epilepsies: Analysis of 2833 individuals reveals a delay in the utilization of genetic testing for many patients. Presented at: 72nd Annual Meeting of the American Epilepsy Society; November 30-December 4, 2018; New Orleans, LA. Poster 3.397.