Patient 2 is a female who is currently 5 years 9 months old. She exhibited a delay in achieving some developmental milestones, such as head lifting at 4 months, independent sitting at 1 year and independent walking at 2 years. She could say “baba,” or “mama” at the age of 1 year but exhibited regression in development with subsequent instances of only unconscious articulation. Nevertheless, she possessed non-verbal communication skills. Hand clapping was observed at 8 months. She displayed good eye contact as well as a purposeful hand use. She presented recurrent, febrile or non-febrile, generalized tonic-clonic seizures at 10 months; after being treated with LEV at the age of 15 months, she achieved a seizure-free status. Her seizure, which was characterized as a generalized tonic seizure without fever, relapsed at the age of 3 years and was treated with valproate (VPA) and LEV. She achieved a seizure-free status when she was 3.5 years old. EEG (15 months) findings revealed spike-and-slow waves with bilateral temporal and occipital involvement. MRI findings at the age of 10 months were normal ().
Patient 7 is a female who is currently 2 years 5 months old. She experienced severe hypotonia at infancy and was observed to have developmental delay. She was incapable of both lifting her head at the age of 7 months and sitting independently at the age of 2 years; she was also unable to walk independently, demonstrated no non-verbal communication skills, and was unable to imitate or babble. Poor eye contact as well as head-shaking and hand-clapping behavior were observed at the age of 1 year. She did not display purposeful hand usage. She did not experience seizure. EEG test conducted at the age of 2 years revealed 2–3 Hz sharp-slow waves at the left parietal-occipital region. MRI scans taken at the age of 14 months showed malformation of the corpus callosum, delayed myelination and leukomalacia in the periventricular region ().