Table 4.
Clinical characteristics of patients with Dravet syndrome and benign familial infantile epilepsy
| Total patients with Dravet syndrome | 21 |
| (A) | |
| Female: Male | 14: 7 |
| Age of seizure onset (months) | 5.9 ± 3.0 (range 2 days–16) |
| SMEI: SMEB | 14: 7 |
| Developmental delay | |
| Normal to mild | 5 (23.8) |
| Severe | 16 (76.2) |
| Numbers of seizure type | |
| 1 | None |
| 2 | 7 (33.3) |
| ≥3 | 14 (66.7) |
| Antiseizure medications | |
| ≤2 | 9 (42.9) |
| ≥3 | 12 (57.1) |
| Initial interictal electroencephalogram | |
| Normal | 12 (57.1) |
| Generalized epileptiform discharges | 1 (4.5) |
| Focal epileptiform discharges | 8 (38.1) |
| Detection of disease‐causing variants | 17 (81.0) |
| Pathogenic | 5 (23.8) |
| Likely pathogenic | 12 (57.4) |
| Total patients with BFIE | 13 |
| (B) | |
| Female: Male | 7: 6 |
| Age of seizure onset (months) | 4.8 ± 3.6 (range 3–8) |
| Family history of seizure | 8 (61.5) |
| Family history of PKD | 3 (23.1) |
| Type of seizure | |
| Focal impaired awareness | 6 (46.2) |
| Focal hemiclonic | 2 (15.4) |
| Generalized tonic or tonic‐clonic | 5 (38.5) |
| Antiseizure medications | 13 (100.0) |
| Monotherapy | 6 (46.2) |
| Levetiracetam | 4 |
| Carbamazepine | 1 |
| Valproic acid | 1 |
| Polytherapy | 7 (54.8) |
| Age of last seizure (months) | 8.1 ± 5.3 (range 4–24) |
| PRRT2 variant | 11 (84.6) |
| c.649dupC; p.(Arg217ProfsTer8) | 8 (61.5) |
| c.971del; p.(Gly324GlufsTer13) | 2 (15.4) |
| c.650del; p.(Arg217GlnfsTer12) | 1 (7.7) |
Data are M ± SD or n (%) values.
Abbreviations: BFIE, benign familial infantile epilepsy; MRI, magnetic resonance imaging; PKD, paroxysmal kinesigenic dyskinesia; SMEB, severe myoclonic epilepsy of infancy‐borderland; SMEI, severe myoclonic epilepsy of infancy.