Folinic Acid Responsive Epilepsy in Ohtahara Syndrome Caused by STXBP1 Mutation

BACKGROUND: Ohtahara syndrome is a severe condition with early onset of recurrent unprovoked seizures associated with abnormal electroencephalography and global developmental delay. Folinic acid responsive seizures are treatable causes of Ohtahara syndrome, which is thought to be due to recessive mutations in the ALDH7A1 gene, resulting in deficiency of antiquitin. METHOD: Here we report a girl with Ohtahara syndrome who exhibited transient folinic acid responsiveness but without evidence of antiquitin dysfunction. RESULTS: She was later found to have a known missense mutation (c.1439 C > T, p.P480 L) in exon 16 of the STXBP1 gene. CONCLUSION: For infants presenting with Ohtahara syndrome with responsiveness to folinic acid and negative antiquitin deficiency analyses, genetic testing for other possible causative genes such as STXBP1 mutation is recommended.