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.