Table 1.

Summary of the clinical features in this proband

Features (Human Phenotype Ontology ID)	Proband
Epilepsy
Epileptic encephalopathy (HP:0200134)	+
Generalized tonic seizures (HP:0010818)	+
Generalized tonic-clonic seizures on awakening (HP:0007193)	+
EEG abnormality (HP:0002353)	+
Developmental/intellectual disability
Global developmental delay (HP:0001263)	+
Developmental stagnation at onset of seizures (HP:0006834)	+
Developmental regression (HP:0002376)	+
Absent speech (HP:0001344)	+
Intellectual disability, severe (HP:0010864)	+
Motor delay (HP:0001270)	+
Neurological
Generalized hypotonia (HP:0001290)	+
Appendicular hypotonia (HP:0012389)	+
Infantile axial hypotonia (HP:0009062)	+
Neck muscle weakness (HP:0000467)	+
Rigidity (HP:0002063)	+
Spasticity (HP:0001257)	+
Growth/feeding
Failure to thrive in infancy (HP:0001531)	+
Gastrostomy tube feeding in infancy (HP:0011471)	+
Gastroesophageal reflux (HP:0002020)	+
Dysphagia (HP:0002015)	+
Respiratory
Respiratory difficulties (HP:0002880)	+
Hypoxemia (HP:0012418)	+
Abnormality of the tonsils (HP:0100765)	+
Obstructive sleep apnea (HP:0002870)	+
Dysmorphism
Brachycephaly (HP:0000248)	+
Broad forehead (HP:0000337)	+
Broad nasal root or bridge (HP:0000431)	+
Hypoplastic alae nasi (HP:0000430)	+
Full cheeks (HP:0000293)	+
Gingival overgrowth (HP:0000212)	+
Micrognathia (mild) (HP:0000347)	+
Hypotonic facies	+
Neurological
Exaggerated startle response (HP:0002267)	+
Action tremor (HP:0002345)	+
Blepharospasm (HP:0000643)	+
Bulbar palsy (HP:0001283)	+
Nystagmus (HP:0000639)	+
Miscellaneous
Hyperreflexia (HP:0001347)	+
No social interaction (HP:0008763)	+

EEG, electroencephalograph.