Table II.
Length of the CGG repeat at the FMR1 locus by karyotype: Percent distribution of five categories of the biallelic mean; the proportion with long repeats (genotypic mean, allele 2) and short repeats (allele 1) among women with trisomic losses (cases) compared with women with non-trisomy chromosomally abnormal losses, with chromosomally normal losses, and with live births for (1) the New York sample and (2) the New Jersey sample
| Losses |
Births | |||
|---|---|---|---|---|
| Trisomy | Non-trisomy abnormal | Chromosomally normal | ||
| (1) The New York sample | ||||
| Number of women | 38 | 17 | 11 | 50 |
| Biallelic mean (%)a | ||||
| 19.0–22.0 | 2.6 | 5.9 | 0.0 | 6.0 |
| 22.5–26.0 | 13.2 | 11.8 | 18.2 | 18.0 |
| 26.5–30.0 | 52.6 | 58.8 | 27.3 | 50.0 |
| 30.5–35.0 | 21.0 | 17.6 | 45.4 | 20.0 |
| 35.5–59.5 | 10.5 | 5.9 | 9.1 | 6.0 |
| Genotypic mean: 35.5–58.0 | 10.5 | 5.9 | 18.2 | 4.0 |
| Allele 2: 35–89 | 18.4 | 5.9 | 27.3 | 14.0 |
| Allele 1: 9–19 | 2.6 | 5.9 | 0.0 | 4.0 |
| (2) The New Jersey samplea | ||||
| Number of women | 169 | 65 | 88 | 487 |
| Biallelic mean (%)a | ||||
| 19.0–22.0 | 1.8 | 7.7 | 3.4 | 4.7 |
| 22.5–26.0 | 16.6 | 15.4 | 12.5 | 19.3 |
| 26.5–30.0 | 51.5 | 30.8 | 53.4 | 46.2 |
| 30.5–35.0 | 23.1 | 41.5 | 28.4 | 24.6 |
| 35.5–59.5 | 7.1 | 4.6 | 2.3 | 5.1 |
| Genotypic mean: 35.5–58.0 | 7.1 | 4.6 | 3.4 | 5.1 |
| Allele 2: 35–89 | 16.6 | 15.4 | 15.9 | 14.2 |
| Allele 1: 9–19 | 1.8 | 6.2 | 3.4 | 3.7 |
aPercents may not add to 100% due to rounding.