Table 1.
Characteristics of sibling/proband pairs.
| Sibling | Proband | Within Pair Difference | Test Statistic (df), p | |
|---|---|---|---|---|
| Age: mean (SD) | 33.3 (10.1) | 32.8 (9.8) | 0.4 (4.7) | t (219) = 1.36, 0.174 |
| Male: N (%) | 104 (47) | 164 (75) | 114 (52) | Chi-square (1) = 0.027, 0.87 |
| Years of education: mean (SD) | 15.5 (2.4) | 13.6 (2.1) | 1.9 (2.7) | t (218) = 10.16, <0.0005 |
| Onset age: mean (SD) | NA | 20.9 (5.0) | ||
| Shared Family Characteristics | ||||
| Paternal age at proband's birth: mean (SD) | NA | 30.1 (6.7) | ||
| Maternal age at proband's birth: mean (SD) | NA | 28.2 (5.2) | ||
| Father's years of education: mean (SD) | NA | 15.3 (3.3) | ||
| Mother's years of education: mean (SD) | NA | 14.6 (3.0) | ||
| Multiplex: N (%) | NA | 14 (6) |