Genetic testing used to find cause of childhood seizure disorder

Thanks to genetic testing, researchers have identified the genetic cause of a disease that causes early childhood seizures.

A team from the University of Utah Health have developed high-tech tools to uncover the genetic cause of early infantile epileptic encephalopathy (EIEE), according to a press release.

EIEE is described as a childhood seizure disorder and typically begins with intractable seizures in the first months of life. Though the condition only occurs in about 1.2 of 1,000 live births, infants with the condition typically experience developmental delays, profound intellectual impairments, psychomotor impairments and early death.

“Most patients are on four to five medications and still suffer from frequent, debilitating seizures, from once a week to 50 times a day,” said Betsy Ostrander, MD, an assistant professor of pediatrics at University of Utah Health and first author of a study published in Nature Genomic Medicine.

Several causes, such as structural brain malformations and birth injury, of the condition have been identified. But of those that remain unidentified, most remaining cases of EIEE are presumed to have a genetic basis.

From 2015-16, University of Utah Health researchers recruited subjects with EIEE who didn’t have an underlying diagnosis for the conditions despite prior extensive testing. Researchers tested 14 patients using whole-genome analysis (WGA) and were able to identify “de novo point and INDEL mutations and de novo structural rearrangements in known EIEE genes,” according to the study. They also identified mutations in genes not previously associated with EIEE.

"The detection of a pathogenic or likely pathogenic mutation in all 14 subjects demonstrates the utility of WGA to reduce the time and costs of clinical diagnosis of EIEE," the study said.

Based on the results, researchers believe WGA is a more efficient strategy for the clinical diagnosis of EIEE and other genetic conditions.

“Given the continued improvements in the cost and speed of whole-genome sequencing, we argue that, in the next few years, whole-genome sequencing approaches are likely to become the standard approach to arriving at a definitive EIEE diagnosis,” the study said.

“We anticipate that whole-genome sequencing will ultimately provide improvements in the diagnosis of a broad range of other genetic disorders, including leukodystrophies, skeletal dysplasias and congenital cardiac disease.”