Table 5.
Characteristics present by history prior to diagnosis with classic RTT (n = 869*).
| Characteristic | Specific regression | Percent | |
|---|---|---|---|
| Core features | Stereotypies | 86.4% | |
| Fine motor regression | Overall | 77.0% | |
| Holding bottle | 32.2% | ||
| Pincer grasp | 40.8% | ||
| Finger feeding | 40.1% | ||
| Language regression | Overall | 87.3% | |
| Babbling | 37.9% | ||
| Single word with meaning | 58.7% | ||
| Phrases | 14.5% | ||
| Follow command with gesture | 16.2% | ||
| Follow command without gesture | 10.5% | ||
| Other regression | Gross motor regression** | Overall | 55.7% |
| Pull to sit | 9.0% | ||
| Crawling | 16.6% | ||
| Walk independently | 4.8% | ||
| Loss of attention | Visual | 22.8% | |
| Auditory | 19.8% | ||
| Supportive features | Bruxism | 56.7% | |
| Constipation | 43.4% | ||
| Self-abusive | 41.5% | ||
| Drooling | 39.2% | ||
| Breath-holding | 30.7% | ||
| Gastro-esophageal reflux | 30.6% | ||
| Hyperventilation | 24.6% | ||
| Aerophagia | 22.2% | ||
| Scoliosis | 8.9% | ||
| Bone fractures | 6.3% | ||
| Gallbladder dysfunction | 0.6% | ||
*
50 participants had incomplete data on development and supportive features
**
Gait apraxia (a core diagnostic feature) could not be evaluated retrospectively, therefore gross motor regression is reported.