Clinical utility of multigene panel testing in adults with epilepsy and intellectual disability
Author(s) -
Borlot Felippe,
Almeida Bruno Ivo,
Combe Shari L.,
Andrade Danielle M.,
Filloux Francis M.,
Myers Kenneth A.
Publication year - 2019
Publication title -
epilepsia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.687
H-Index - 191
eISSN - 1528-1167
pISSN - 0013-9580
DOI - 10.1111/epi.16273
Subject(s) - epilepsy , proband , intellectual disability , etiology , medicine , pediatrics , genetic testing , psychiatry , epilepsy syndromes , genetics , gene , biology , mutation
Abstract Objective To determine the diagnostic yield of a commercial epilepsy gene panel in adults with chronic epilepsy and accompanying intellectual disability, given that genetic evaluation is often overlooked in this group of patients. Methods This is a cross‐sectional study analyzing the results of epilepsy gene panels including up to 185 genes in adult epilepsy patients with intellectual disability, according to Diagnostic and Statistical Manual of Mental Disorders, fifth edition. Patients with acquired structural brain abnormalities or known chromosomal abnormalities were excluded. Results From approximately 600 patients seen from January 2017 to June 2018 at a single academic epilepsy center, 64 probands and two affected relatives (32 males, mean age = 31 years ± 10) were selected and clinically tested. Fourteen probands (14/64 = 22%; four males, mean age = 32 years ± 10) were found to have pathogenic or likely pathogenic variants in the following genes: SCN 1A , GABRB 3 , UBE 3A , KANSL 1 , SLC 2A1 , KCNQ 2 , SLC 6A1 , HNRNPU , STX 1B , SCN 2A , PURA , and CHD 2 . Six variants arose de novo, and the inheritance was not determined in eight. Nine probands (64%) had severe or profound intellectual disability, and five (35%) had autistic features. Eight patients (57%) had a diagnostic change from presumptive clinical diagnosis prior to genetic testing. Significance We were able to demonstrate that a commercial epilepsy gene panel can be an important resource in clinical practice, identifying the etiology in 22% of adults with epilepsy and intellectual disability. The diagnostic yield is similar to previously reported pediatric cohorts. Larger samples would be required to evaluate the more prevalent genotypes among adult epilepsy patients.