A developmental and epileptic encephalopathy characterized by onset in the first months of life of severe refractory seizures, multifocal spikes and hypsarrhythmia on EEG, severely impaired intellectual development with inability to walk, absent speech, and hypotonia with axial hyperreflexia that has_material_basis_in homozygous or compound heterozygous mutation in PARS2 on chromosome 1p32.3.