TABLE 1

Patient Characteristics

Patient No.Initial DevelopmentSeizure Onset, moTime Between Vaccinations and Seizure, hInitial Seizure TypeSubsequent SeizuresDevelopment and Behavioral IssuesBrain MRIEEG at DiagnosisSCN1A TestingAge at Diagnosis of Dravet Syndrome, y
1Normal7<12Febrile generalized convulsionGTCs, myoclonic, partialPlateau age: 2 y; autistic-like featuresNormalGeneralized, focal dischargesDe novo missense mutation (G529A, Gly177Arg)14
2Normal2<12Febrile generalized convulsionGTCs, HCs, partialDelayed; autistic-like featuresNormalFocal discharges, slowingDeletion of one copy of all 26 exons20
3Normal4<12Febrile generalized convulsionGTCs, partialMild expressive speech delayInitial abnormality resolvedNormalDe novo missense mutation (A1171C, Thr391Pro)2
4Normal6<24Afebrile unilateral clonic seizureGTCs, HCs, myoclonicSlowingNormalGeneralized discharges, slowingDe novo nonsense mutation (C5734T, Arg1912Stop)4
5Normal4<24Afebrile unilateral clonic seizureGTCs, HCs, myoclonic, absenceRegression age 1 y; autistic-like featuresNormalGeneralized, focal dischargesDe novo missense mutation (T4837C, Phe1463Leu)3
  • EEG indicates electroencephalogram; GTC, generalized tonic-clonic seizure; HCs, hemiconvulsions; de novo mutations, the parents' test results were negative.