Table IV.

Length of the CGG repeat at the FMR1 locus by trisomy type: percent distribution of five categories of the biallelic mean among women with trisomic losses (cases) classified by trisomy type and women with live births for (1) the New York sample and (2) the New Jersey sample; adjusted odds ratios [95% confidence intervals (CI)] relating length in the longest and shortest categories to trisomy type.

	Losses			Births
	Trisomy 16	Other non-acrocentric trisomy	Acrocentric trisomy
(1) The New York sample
Number of women	14	7	15	50
Biallelic mean (%)
19.0–22.0	7.1	0.0	0.0	6.0
22.5–26.0	7.1	14.3	13.3	18.0
26.5–30.0	35.7	57.1	66.7	50.0
30.5–35.0	28.6	14.3	20.0	20.0
35.5–59.5	21.4	14.3	0.0	6.0
(2) The New Jersey sample
Number of women	41	40	78	487
Biallelic mean (%)
19.0–22.0	4.9	0.0	1.3	4.7
22.5–26.0	19.5	15.0	17.9	19.3
26.5–30.0	46.3	52.5	48.7	46.2
30.5–35.0	24.4	25.0	23.1	24.6
35.5–59.5	4.9	7.5	9.0	5.1
Adjusted odds ratio (95% CI)a
35.5–59.5 versus 26.5–30.0	1.5 (0.4, 5.0)	2.2 (0.7, 7.7)	1.6 (0.6, 4.1)
19.0–22.0 versus 26.5–30.0	1.4 (0.4, 5.5)	NA	0.3 (0.0, 2.0)

NA, not estimated because there were no other non-acrocentric trisomies with biallelic mean 19.0–22.0.

^aOdds ratios from conditional maximum likelihood logistic regression. Analyses adjust by stratification for site (New York, New Jersey) and age in single years and by indicator variable for race (White non-Hispanic versus Other). Analyses exclude 12 women (2 New York, 10 New Jersey) with double trisomies.