BACKGROUND: Mutations in the elongation factor 1 alpha 2 ( @entity9221 ) gene have recently been shown to cause severe @entity717 with early-onset @entity302 . The specific manifestations of mutations in this gene remain unknown. CASE REPORT: We report two cases of severe @entity717 accompanied by early-onset @entity302 with continuous delta activity evident on electroencephalography. Both cases presented with @entity245 and repetitive @entity410 in early infancy. Both cases showed continuous high-voltage delta activity over both parietal areas when awake, as revealed by interictal electroencephalograms. After the emergence of continuous delta activity, development stagnated. One case showed some development after relief of the @entity410 and @entity302 activity, but drug resistant @entity410 recurred, and the development again became stagnant. In both cases, a de novo recurrent heterozygous mutation in @entity9221 [ @entity69091 ( @entity69092 )] was identified by whole-exome sequencing. CONCLUSION: This report provides clinical data on @entity302 in @entity1 with @entity9221 mutation. Continuous high-voltage delta activity seen over both parietal areas may be a unique manifestation of @entity9221 mutation. @entity302 activity may aggravate the effect of the mutation on brain development.

Two cases of early-onset XXXX with continuous parietal delta activity caused by @entity9221 mutations.

@entity69091 :: ('c|SUB|G|364|A', 'DNAMutation') :: ['c.364G>A'] @entity1 :: ('9606', 'Species') :: ['patients'] @entity410 :: ('MESH:D012640', 'Disease') :: ['seizures', 'myoclonic seizures'] @entity9221 :: ('1917', 'Gene') :: ['EEF1A2'] @entity245 :: ('MESH:D002658', 'Disease') :: ['developmental delay'] @entity302 :: ('MESH:D004827', 'Disease') :: ['epileptic', 'epileptic encephalopathy', 'epilepsy', 'Epileptic'] @entity717 :: ('MESH:D009069', 'Disease') :: ['intellectual disability'] @entity69092 :: ('p|SUB|E|122|K', 'ProteinMutation') :: ['p.E122K']
@entity410 :: (MESH:D012640,Disease) :: ['myoclonic seizures']
