Table 1 Baseline clinical characteristics of participants from the Rett syndrome natural history study (RNHS) analyzed in this study
From: Anxiety-like behavior and anxiolytic treatment in the Rett syndrome natural history study
Characteristic | Category | First iteration (n = 1070) | Second iteration (n = 662) | |
Race1** | White | 88% | 92% | |
Black or African American | 7% | 5% | ||
American Indian or Alaska Native | 3% | 1% | ||
Asian | 5% | 5% | ||
Native Hawaiian or Pacific Islander | (Not assessed) | 1% | ||
Ethnicity* | Not Hispanic, Latino, or Spanish Origin | 85% | 87% | |
Hispanic, Latino, or Spanish Origin | 15% | 11% | ||
RTT diagnosis | Classic (typical) | 87% | 89% | |
Variant (atypical) | 13% | 11% | ||
MECP2Â severity | Mild | 32.5% | 35.0% | |
Moderate | 16.7% | 17.0% | ||
Severe | 50.8% | 47.9% | ||
Age*** |  | 9.1 years ± 8.8 (range 1–66) | 15.2 years ± 10.7 (range 1–58) | |
CSS total*** |  | 22.2 ± 7.8 | 23.8 ± 8.3 | |
MBA total** |  | 46.9 ± 15.0 | 48.8 ± 13.8 | |
| Â | Â | Cohort 1 (n = 718) | Both studiesa (n = 352) | Cohort 2 (n = 310) |
RTT diagnosis | Classic (typical) | 83.4% | 93.5%*** | 83.2% |
Variant (atypical) | 16.6% | 6.5%*** | 16.8% | |
MECP2Â severity | Mild | 32.4% | 32.7% | 37.7% |
Moderate | 16.4% | 17.1% | 17.0% | |
Severe | 51.1% | 50.1% | 45.3% | |
Age |  | 9.22 ± 8.6 (range 1–66) | 8.84 ± 9.1 (range 1–48) | 12.56 ± 10.7*** (range 1–52) |
CSS total |  | 22.92 ± 7.9 | 20.79 ± 7.4*** | 22.18 ± 8.4 |
MBA total |  | 49.01 ± 15.2 | 42.64 ± 13.6*** | 47.84 ± 14.5 |