A) DS patients with a SCN1A mutation inherited by a mosaic parent. (B) DS patients with a SCN1A mutation inherited in a GEFS+ familial context
| A. DS patients with a SCN1A mutation inherited by a mosaic parent | ||||||
| Family | Number of SMEI children | Mutation type (Mutation) | Transmission to the SMEI child | Clinical status of transmitting parent | % of mutated allele in parent's blood cells (TaqMAMA quantification) | Detection of the mutation in parent's blood cells (direct sequencing) |
| 1 | 1 | Truncating (c.1378+1G>A) | Paternal | Severely affected but not DS | 85.18±12 | Yes |
| 2 | 1 | Truncating (c.3878delA) | Paternal | Affected | 64.59±10 | Yes |
| 3 | 2 | Truncating (p.Arg542X) | Maternal | Unaffected | 54.04±4 | Yes |
| 4 | 2 | Truncating (602+1G→A) | Maternal | Unaffected | 50.06±6 | Yes |
| 5 | 1 | Missense (p.Ile124Asn) | Maternal | Severely affected but not DS | 49.77±5 | Yes |
| 6 | 1 | Truncating (p.Arg712X) | Maternal | Unaffected | 45.70±7 | Yes |
| 7 | 1 | Missense (p.Asn191Tyr) | Paternal | Affected | 45.33±8 | Yes |
| 8 | 2 | Truncating (c.5493delT) | Maternal | Affected | 43.05±7 | Yes |
| 9 | 1 | Missense (p.Ile1782Met) | Paternal | Affected (seizures after a head trauma) | 33.63±5 | Yes |
| 10 | 1 (+1 child prematurely deceased) | Truncating (p.Arg1912X) | Paternal | Unaffected | 17.52±1 | No |
| 11 | 2 | Truncating (c.965-2A→C) | Paternal | Unaffected | 6.05±2 | No |
| 12 | 1 | Truncating (p.Arg580X) | Maternal | Unaffected | 0.04±0.01 | No |
| 13 | 2 | Whole gene deletion | NA | Unaffected | NA | NA |
| B. DS patients with a SCN1A mutation inherited in a GEFS+ familial context | ||||
| Family | Number of SMEI children | Transmission to the SMEI child | Clinical status of transmitting parent | Mutation type (mutation) |
| 14 | 1 | Paternal (de novo in the father) | Affected | Missense (p.Thr875Lys) |
| 15 | 1 | Paternal (de novo in the father) | Affected | Missense (p.Asn1367Lys) |
| 16 | 1 | Maternal (familial) | Affected | Missense (p.Leu1514Ser) |
| 17 | 1 | Paternal inheritance suspected (familial) | Unaffected | Missense (p.Arg1648His) |
| 18 | 1 | Maternal (familial) | Unaffected | Missense (p.Thr1658Met) |
| 19 | 1 | Maternal (familial) | FS | Missense (p.Met1664Lys) |
DS, Dravet syndrome;GEFS†, genetic epilepsy with febrile seizures plus;NA, not available;SMEI, sever myoclonic epilepsy in infancy