Newly discovered variants in unexplained neonatal encephalopathy

Mol Genet Genomic Med. 2024 Jan;12(1):e2354. doi: 10.1002/mgg3.2354.

Abstract

Background: The genetic background of neonatal encephalopathy (NE) is complicated and early diagnosis is beneficial to optimizing therapeutic strategy for patients.

Methods: NE Patients with unclear etiology received regular clinical tests including ammonia test, metabolic screening test, amplitude-integrated electroencephalographic (aEEG) monitoring, brain Magnetic Resonance Imaging (MRI) scanning, and genetic test. The protein structure change was predicted using Dynamut2 and RoseTTAFold.

Results: 15 out of a total of 113 NE Patients were detected with newly reported pathogenic variants. In this sub-cohort, (1) seizure was the primary initial symptoms; (2) four patients had abnormal metabolic screening results, and two of them were also diagnosed with excessive blood ammonia concentration; (3) the brain MRI results were irregular in three infants and the brain waves were of moderate-severe abnormality in about a half of the patients. The novel pathogenic variants discovered in this study belonged to 12 genes, and seven of them were predicted to introduce a premature translation termination. In-silicon predictions showed that four variants were destructive to the protein structure of KCNQ2.

Conclusion: Our study expands the mutation spectrum of genes associated with NE and introduces new evidence for molecular diagnosis in this newborn illness.

Keywords: neonatal encephalopathy; next generation sequencing; novel pathogenic variants; seizure.

MeSH terms

  • Ammonia*
  • Brain
  • Brain Diseases* / diagnosis
  • Brain Diseases* / genetics
  • Electroencephalography / adverse effects
  • Electroencephalography / methods
  • Humans
  • Infant
  • Infant, Newborn
  • Seizures / diagnosis

Substances

  • Ammonia