Table 1.
Descriptive demographic, medical, and seizure history among individuals with AS by molecular etiology
| Variable |
Overall N = 302 |
Deletion N = 212 |
Non‐deletion N = 87 |
p‐valuea |
|---|---|---|---|---|
| Molecular diagnosis, n (%) | ||||
| Abnormal DNA methylation | 6 (2) | — | 3 (3) | — |
| UBE3A mutation | 33 (11) | — | 33 (38) | |
| UPD | 29 (10) | — | 29 (33) | |
| Imprinting defect | 22 (7) | — | 22 (25) | |
| Deletion | 212 (70) | 212 (100) | — | |
| Age at baseline, years, mean (SD) | 5.5 (5.9) | 5.5 (6.5) | 5.6 (4.2) | 0.9338 |
| Age at diagnosis, years; mean (SD) | 2 (3) | 1.7 (3.1) | 2.9 (2.5) | 0.0007 |
| Male, n (%) | 145 (48) | 96 (45) | 46 (53) | 0.2527 |
| Female, n (%) | 157 (52) | 116 (55) | 41 (47) | |
| Seizure history, n (%) | ||||
| Clinical seizures | 199 (68) | 156 (77) | 42 (49) | <0.0001 |
| Age at first seizure years; mean (SD) | 1.7 (1.4) | 1.5 (1.2) | 2.3 (1.6) | 0.0025 |
| Seizure typeb, n (%) | ||||
| Absence | 70 (35) | 54 (35) | 16 (38) | 0.7177 |
| Myoclonic | 40 (20) | 32 (21) | 8 (19) | 1.0000 |
| Atonic/drop attacks | 83 (42) | 61 (40) | 21 (50) | 0.2203 |
| Tonic/generalized tonic | 71 (36) | 64 (41) | 7 (17) | 0.0035 |
| Generalized clonic | 46 (23) | 42 (27) | 4 (10) | 0.0223 |
| Other | 53 (27) | 43 (28) | 9 (21) | 0.5538 |
| Had ketogenic diet to control seizures | 5 (3) | 5 (3) | — | |
| Other medical history, n (%) | ||||
| Otitis media | 149 (51) | 98 (48) | 50 (59) | 0.1210 |
| Pneumonia | 72 (25) | 50 (25) | 22 (27) | 0.7650 |
| Gastrointestinal reflux | ||||
| Never formally diagnosed | 59 (20) | 39 (19) | 20 (23) | 0.1312 |
| Diagnosed | 136 (46) | 91 (44) | 45 (52) | |
| Vomiting with feeds | 61 (21) | 43 (21) | 17 (20) | 0.8751 |
| Gagging | 146 (50) | 102 (50) | 42 (50) | 1.0000 |
| Tight heels cords/toe walking | 109 (40) | 70 (37) | 37 (45) | 0.2809 |
| Strabismus | 147 (50) | 116 (57) | 31 (37) | 0.0028 |
| Sleep issues | 241 (82) | 168 (81) | 71 (85) | 0.6129 |
Percentages have been rounded to the nearest integer.
Abbreviations: AS, Angelman syndrome; SD, standard deviation; UPD, uniparental disomy.
a
p‐values comparing deletion versus non‐deletion cohort were performed using an independent samples t test or Fisher's exact test, as appropriate.
b
Individuals can be counted in more than one seizure type.