TABLE 1.
Findings (proportional) of genetic testing in brain tissue according to histopathology in the NL cohort (n = 123) and in all four cohorts combined (n = 663).
| Histopathology | Genetic + MRI findings | MRI‐negative | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| n | No pathogenic variant | (Likely) pathogenic variant, n = 166 | |||||||||
| All | SLC35A2 | DEPDC5 | NPRL2/3 | MTOR | PTEN, PIK3CA, AKT3, RHEB | TSC1/2 | Other | ||||
| NL, n (%) | |||||||||||
| All | 123 | 84 (68) | 42 (34) | 7 (6) | 7 (6) | 2 (2) | 16 (13) | 3 (2) | 7 (6) | 0 | 34 (28) |
| No lesion | 26 | 25 (96) | 1 (4) | 1 (4) | 0 | 0 | 0 | 0 | 0 | 0 | 15 (58) |
| FCDI | 1 | 1 (100) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| mMCD | 29 | 19 (66) | 10 (34) | 5 (17) | 1 (3) | 0 | 2 (7) | 0 | 2 (7) | 0 | 7 (25) |
| MOGHE | 1 | 0 | 1 (100) | 1 (100) | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| FCDII | 65 | 33 (51) | 32 (49) | 0 | 6 (12) | 2 (3) | 14 (21) | 3 (5) | 5 (78) | 0 | 11 (17) |
| HMEG | 1 | 1 (100) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Pooled cohorts, n (%) | |||||||||||
| All | 663 | 460 (69) | 203 (31) | 41 (6) | 23 (3) | 7 (1) | 78 (12) | 23 (3) | 23 (3) | 8 (1) | 74 (27) a |
| No lesion | 69 | 63 (91) | 6 (9) | 5 (8) | 1 (1) | 0 | 0 | 0 | 0 | 0 | 52 (76) |
| FCDI | 69 | 59 (86) | 10 (14) | 4 (6) | 1 (2) | 0 | 0 | 0 | 0 | 5 (8) | 0 |
| mMCD | 77 | 57 (74) | 20 (26) | 14 (18) | 2 (4) | 0 | 2 (4) | 0 | 2 (4) | 0 | 6 (18) |
| MOGHE | 32 | 14 (44) | 18 (56) | 18 (56) | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| FCDII | 379 | 253 (67) | 126 (33) | 0 | 18 (5) | 7 (2) | 70 (18) | 8 (2) | 21 (6) | 2 (1) | 16 (15) |
| HMEG | 37 | 14 (38) | 23 (62) | 0 | 1 (3) | 0 | 6 (16) | 15 (40) | 0 | 1 (3) | 0 |
Abbreviations: FCDI, focal cortical dysplasia type I; FCDII, focal cortical dysplasia type II; HMEG, hemimegalencephaly; mMCD, mild malformations of cortical development; MOGHE, mMCD with oligodendroglial hyperplasia and epilepsy; MRI, magnetic resonance imaging; NL, the Netherlands.
a
No exact information on MRI outcome could be retrieved in 381 patients.