Keywords: EEG; electroencephalography; GABA; γ-aminobutyric acid; SSADH; succinic semialdehyde dehydrogenase; Succinic semialdehyde dehydrogenase deficiency; ALDH5A1 gene; 4-Hydroxybutyric aciduria; γ-Aminobutyric acid (GABA); Novel mutation; Prenatal diagnosis;