Comparison of the clinical data from the present study and those reported by Van Esch et al and Lim et al 10–12
| Van Esch et al (%) | Lim et al (%) | Present study (%) | |
| Patient number | 129 | 49 | 59 |
| Gender | M | M | M |
| Age at diagnosis (years) | NR | 3 | 10 |
| Age at examination (years) | NR | 7.9 | 12 |
| Neonatal complications | NR | 33* | 32/58 (55) |
| Early death (<25 years) | 34/88 (39) | NR | 9/59 (15) |
| Facial dysmorphism | 65/86 (76) | NR | 51/55 (93) |
| Growth | |||
| Head circumference (SDS) | Normal range | NR | 0.2 |
| Height (SDS) | Normal range | NR | −0.4 |
| Weight (SDS) | Normal range | NR | 0.4 |
| Neurodevelopment | |||
| Developmental delay | 129/129 (100) | 41/49 (84) | 59/59 (100) |
| Early hypotonia | 110/117 (94) | 31/48 (65) | 57/58 (98) |
| Seizures | 66/123 (54) | 21/49 (43) | 35/59 (59) |
| Drug resistance | NR | 17/21 (81) | 21/34 (62) |
| Age at onset of seizures (years) | 6 | 1 to 20 | 7.4 |
| Type of seizures | TC, At, Ab, M | NR | TC, At, Ab, M, CP |
| Walking age (years) | 18 months to 4 years | 4 | 3.6 |
| Walking without support | 83/109 (76) | 13/49 (27) | 37/56 (66) |
| Absent speech | 86/109 (79) | 23/46 (50) | 32/57 (56) |
| Stereotyped movements | 20/78 (26) | 55% at 3 years | 49/55 (89) |
| Gastrointestinal anomalies | |||
| Chronic constipation | 29/88 (33) | 37/45 (82) | 43/55 (78) |
| Gastrooesophageal reflux | NR | 26/49 (53) | 34/51 (67) |
| Recurrent pulmonary infections | 87/121 (72) | 38/49 (78) | 49/55 (89) |
| Skeletal anomalies | |||
| Flexion of the knees and the trunk | 57/89 (64) | NR | 42/49 (86) |
| Scoliosis and/or kyphosis | NR | 10/46 (22) | 23/43 (53) |
| Decreased pain sensitivity | NR | 25/50* (50) | 29/37 (78) |
*Includes both males and females.
At, atonic; M, myoclonic; Ab, absence; CP, complex partial; TC, tonic-clonic; NR, not reported; SDS, SD score.