Title

Novel SCN2A mutation in a proband with migrating focal seizures of infancy

Document Type

Article

Department

Paediatrics and Child Health

Abstract

Introduction: Migrating focal seizures of infancy is characterized by seizure onset within 7 months of age, migrating focal motor seizures with multifocal ictal electroencephalography discharges, intractable to conventional antiepileptic drugs and poor prognosis. Reported genetic etiologies include SCN1A and KCNT1 mutations and homozygous deletion of the PLCB1 gene. Here we report a novelSCN2A mutation in a child with this syndrome.
Case report: A 7 week old female infant was admitted toour hospital for management of status epilepticus. She was product of a full term healthy pregnancy. Seizures started around 5 weeks of age and remained medically refractory. Physical examination was significant for encephalopathy, dif-fuse hypotonia and absence of normal new born reflexes. Head MRI was normal. EEG showed multifocal epileptiform discharges as well as seizures arising from multifocal region sin both cerebral hemispheres. Based on her phenotype a diagnosis of migrating focal seizures of infancy was made. Genomic DNA was isolated from blood and submitted for commercial testing. A novel missense mutation was identified in the SCN2A gene, exon 22 (coding for voltage gated sodium channel type II): c.3977T>A (p.V1326D). Parental testing was negative for the same mutation, thus confirming a de novo change. This mutation affects a highly evolution ar-ily conserved area of the gene, and replaces hydrophobic non-polar valine with polar aspartic acid, thus predicted to affect protein function, and presumed pathogenic.
Conclusion: This report expands our knowledge of the genetic basis of migrating focal seizures of infancy to include mutations in SCN2A gene.

Comments

This work was published before the author joined Aga Khan University.

Publication

Annals of Neurology

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