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 ().
Patient 3 is a female who is currently 4 years 4 months old. She showed some signs of developmental delay, such as lifting her head at the age of 5 months, sitting independently at the age of 9 months, and walking at the age of 2 years; she also did not exhibit any non-verbal communication skills and could not imitate actions or babble. Poor eye contact was observed at the age of 8 months. Hand clapping and hand wringing were observed when she was 1 year 6 months old. She demonstrated purposeful hand use, and at the age of 8 months, she experienced recurrent, febrile or non-febrile, generalized tonic-clonic seizures. She presented with status epilepticus, which later became absence status epilepticus at the age of 3 years 2 months. At this time, she was started on LEV medication but showed no response to it; subsequently, VPA was added to the treatment strategy at the age of 3 years 6 months, and the patient finally achieved a seizure-free status at the age of 4 years. Her EEG tests at the age of 15 months demonstrated sharp-slow synthetical waves at the left central and left parietal-frontal regions. EEG showed generalized sharp-slow waves and MRI findings indicated delayed myelination in the periventricular area at the age of 3 years 2 months ().