Clinical features of patients with MECP2 mutations
| Patient 1 | Patient 2 | Patient 3 | Patient 4 | Patient 5 | |
| Sex | F | F | F | F | M |
| Age at suspected diagnosis of AS | 3 y | 3 y | 2 y | 12 mth | 3 y |
| Age atMECP2 testing | 7 y | 11 y | 9 y | 7 y | 7 y |
| Age at sitting | 12 mth | 7 mth | 3 y | Unable | 12 mth |
| Age at walking | Non-ambulant | Non-ambulant | Non-ambulant | Non-ambulant | 15 mth |
| Microcephaly | + | + | + | + | − |
| Brachycephaly | + | + | + | + | + |
| Prominent chin | + | + | + | + | + |
| Truncal hypotonia | + | + | + | + | + |
| Limb spasticity | + | − | − | + | + |
| Scoliosis | + | + | − | + | + |
| Seizures | + | − | − | − | + |
| Abnormal EEG | + | + | − | − | + |
| Ataxia | +/− | + | +/− | +/− | + |
| Tremor | + | ++ | − | + | + |
| Titubation | + | + | − | − | + |
| Hand flapping | − | − | + | − | + |
| Repetitive hand movements | + | + | + | + | + |
| Hand wringing | − | − | +/− | − | − |
| Severe learning disability | + | + | + | + | + |
| History of early regression | + | + | − | − | + |
| Feeding problems | + | + | + | − | − |
| Drooling | − | + | − | + | + |
| Bruxism | + | + | − | − | + |
| Absent speech | + | + | + | + | + |
| Hyperventilation | − | − | +/− | − | +/− |
| Sleep disorder | − | − | − | − | − |
| Short stature | − | − | − | − | + |
| Small, cold feet | + | − | − | + | + |
| Fair hair/blue eyes | − | − | − | − | + |
| Hirsutism | + | + | − | − | − |