TABLE 1.
Clinical characteristics of children aged ≥24 to ≤60 months with seizure onset after 24 months of age tested through the Behind the Seizure® program (Cohort 1A)
| Clinical characteristic, n (%) | No MDx, n = 1661 | All MDx, n = 152 | CLN2 MDx, n = 17 | p, No MDx vs. | ||||
|---|---|---|---|---|---|---|---|---|
| Yes | No | Yes | No | Yes | No | All MDx | CLN2 MDx | |
| Language delay | 688 (46.5) | 792 (53.5) | 96 (66.7) | 48 (33.3) | 12 (80.0) | 3 (20.0) | <.001 | .002 |
| Motor delay | 383 (27.4) | 1015 (72.6) | 74 (54.4) | 62 (45.6) | 11 (84.6) | 2 (15.4) | <.001 | <.001 |
| Language OR motor delay | 756 (51.4) | 716 (48.6) | 104 (71.7) | 41 (28.3) | 14 (93.3) | 1 (6.7) | <.001 | .001 |
| Language AND motor delay | 315 (22.4) | 1091 (77.6) | 66 (48.9) | 69 (51.1) | 9 (69.2) | 4 (30.8) | <.001 | <.001 |
| Developmental delay precedes seizure onset | 403 (35.0) | 750 (65.0) | 74 (60.7) | 48 (39.3) | 6 (66.7) | 3 (33.3) | <.001 | .07 |
| Abnormal EEG | 707 (51.8) | 658 (48.2) | 87 (65.9) | 45 (34.1) | 13 (81.3) | 3 (18.7) | .002 | .02 |
| Abnormal MRI | 178 (15.0) | 998 (85.0) | 29 (24.6) | 89 (75.4) | 6 (60.0) | 4 (40.0) | .01 | .002 |
| Family history of epilepsy | 215 (36.9) | 368 (63.1) | 13 (25.5) | 38 (74.5) | 2 (40.0) | 3 (60.0) | .13 | 1.00 |
Total number of patients in each group includes only patients with available medical history data for at least one clinical characteristic. Percentages are based on the number of patients for whom the ordering clinician indicated the presence (“Yes”) or absence (“No”) of each clinical characteristic, which may not total the overall n indicated in the top row. MDx = definitive molecular diagnosis determined based on genetic testing results, defined as two P/LP variants in genes associated with autosomal recessive disorders, one P/LP variant in genes associated with autosomal dominant disorders, X‐linked dominant disorders, or X‐linked recessive disorders (male only); No MDx = negative result defined as the absence of any reportable results, including variant of uncertain significance and single P/LP variants in a gene associated with autosomal recessive disorders; All MDx = children with any positive MDx; CLN2 MDx = children with biallelic TPP1 P/LP variants. See Figure S2 for a graphic representation of these data.
Abbreviations: CLN2, ceroid lipofuscinosis type 2; EEG, electroencephalogram; LP, likely pathogenic; MRI, magnetic resonance imaging; P, pathogenic.