GABA‐transaminase (GABA‐T) deficiency (OMIM#613163) is a rare disorder of GABA metabolism characterized by encephalopathy, hypotonia, developmental delay and epilepsy, presenting in the neonatal period or early infancy [1] Gamma‐aminobutyric acid (GABA) is a primary inhibitory neurotransmitter of the central nervous system. This evidence concerns the gene ABAT and hyperinsulinemic hypoglycemia, familial, 4.