TABLE I.
Age Distribution by the End of Follow-up According to Sex and Karyotype among Persons with Down Syndrome (Birth Year: 1968–2007; Follow-up: 1980–2007)
| 0–6 years | 7–17 years | 18–25 years | 26–39 years | Total | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| n | % | n | % | n | % | n | % | n | % | |
| Total | 426 | 21.3 | 628 | 31.4 | 352 | 17.6 | 592 | 29.6 | 1,998 | 100.0 |
| Sex | ||||||||||
| Female | 203 | 47.7 | 275 | 43.8 | 147 | 41.8 | 268 | 45.3 | 893 | 44.7 |
| Male | 223 | 52.3 | 353 | 56.2 | 205 | 58.2 | 324 | 54.7 | 1,105 | 55.3 |
| Karyotype | ||||||||||
| Standard trisomy 21 | 405 | 95.1 | 589 | 93.8 | 318 | 90.3 | 540 | 91.2 | 1,852 | 92.7 |
| Robertsonian translocation DS | 13 | 3.1 | 21 | 3.3 | 13 | 3.7 | 33 | 5.6 | 80 | 4.0 |
| Mosaic DS | 8 | 1.9 | 18 | 2.9 | 21 | 6.0 | 19 | 3.2 | 66 | 3.3 |
DS: Down syndrome.
χ2 tests: P = 0.39 for sex, and P = 0.011 for karyotype.