Table 2.

Probandwise concordance rate, odds ratio, tetrachoric correlation and heritability for DD in female Danish twins.

Zygosity	Concordant pairs (both with DD)	Discordant pairs (one with and one without DD)	Concordant pairs (both without DD)	Probandwise concordance rate (95% CI)	Odds ratio (95% CI)a	Tetrachoric correlationb (95% CI)	Heritability (95% CI)
Diagnosis
Monozygotic	2	17	5609	0.27 (0.09 to 0.58)	160.3 (29.6 to 868.1)	0.77 (0.44 to 0.92)	0.81 (0.60 to 0.92)
Dizygotic	3	56	9234	0.09 (0.03 to 0.23)	36.1 (10.3 to 125.8)	0.51 (0.27 to 0.70)
Diagnosis + operation
Monozygotic	2	9	5617	0.41 (0.15 to 0.73)	561.7 (83.1 to 3,795.2)	0.87 (0.57 to 0.97)	0.89 (0.67 to 0.97)
Dizygotic	2	36	9255	0.09 (0.02 to 0.29)	67.3 (14.2 to 319.3)	0.55 (0.25 to 0.75)

CI: confidence interval; DD: Dupuytren’s disease.

^aTest-based $(O{R}^{1\pm 1.96/\sqrt{{\mathrm{x}}^2}})$.

^bLikelihood Ratio Test for equal correlations. Diagnosis p = 0.15; diagnosis + operation p = 0.058.