Lab Med Online.  2022 Apr;12(2):134-137. 10.47429/lmo.2022.12.2.134.

De novo HCN1 Mutation Identified by Next-Generation Sequencing in a Patient with Early Infantile Epileptic Encephalopathy: Case Report

Affiliations
  • 1Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea
  • 2Division of Pediatric Neurology, Department of Pediatrics, Yonsei University College of Medicine, Epilepsy Research Institute, Seoul, Korea

Abstract

Early infantile epileptic encephalopathy (EIEE) is a group of brain disorders characterized by spontaneous seizures occurring at an early age. EIEE is caused by mutations in various genes, including HCN1. Here, we report a Korean patient with EIEE carrying a de novo mutation in the HCN1 gene. A female infant with unremarkable birth and family history showed status epilepticus four months after birth. Next-generation sequencing analysis revealed a heterozygous missense mutation, c.794T>A(p.Leu265His), in HCN1. The variant was not observed in any population control dataset, and in silico pathogenicity analyses predicted the variant to be pathogenic. Subsequent family testing by Sanger sequencing confirmed that the variant was a de novo mutation. These findings provide insights for predicting patient prognosis and the possibility of developing targeted therapy.

Keyword

HCN1; Neurodevelopmental disease; Early infantile epileptic encephalopathy; de novo mutation; Next-generation sequencing

Figure

  • Fig. 1 Sequencing chromatograms of HCN1 gene from (A) proband, (B) proband’s mother, and (C) proband’s father showed that the mutation identified in the proband was in de novo form.


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