. Author manuscript; available in PMC: 2011 Oct 1.

Published in final edited form as: Am J Med Genet A. 2010 Oct;152A(10):2468–2474. doi: 10.1002/ajmg.a.33608

TABLE III.

Twin pairs discordant for isolated oral cleft. Zygosity stratification of recurrence risk and relative risk, Denmark 1956 to 2005

Twin parents status		Recurrence		Recurrence risk (%) [95% confidence interval]	Relative risk^*, [95% confidence interval]

Zygosity	Oral Cleft	Number Affected (n)	Total (N)
Monozygotic	No	2	26	7.7 [ 0.95 ; 25 ]	42 [ 5.3 ; 140 ]
Monozygotic	Yes	0	16	0	0

Dizygotic	No	1	103	0.97 [ 0.025 ; 5.3 ]	5.3 [ 0.17 ; 29 ]
Dizygotic	Yes	2	90	2.2 [ 0.27 ; 7.8 ]	12 [ 1.7 ; 43 ]

Significant if p<0.05, in bold

Compared to the risk in the background population born in the same time period