Table 3. Haplotypes of the BMP9 SNPs in cases and controls.

Haplotypes	rs7923671T>C	rs75024165C>T	rs34379100A>C	rs9421799C>A	Frequency		χ2(df = 1)	P(χ2)	P(MonteCarlo)	OR	95%CI
					OPLL	Control
Haplotype 1	C	T	C	A	0.37	0.19	70.22	<0.001	<0.01	2.37	1.93–2.90
Haplotype 2	T	C	A	C	0.43	0.44	1.73	0.1882	1.00	0.89	0.74–1.06
Haplotype 3	T	C	A	A	0.07	0.11	12.13	0.0005	1.00	0.58	0.42–0.79
Haplotype 4	T	T	A	A	0.04	0.04	<0.001	0.9988	1.00	1.00	0.64–1.56
Other haplotypes	–				0.09	0.22	–

Note: Haplotype 1 includes the risk alleles of rs75024165 *T and rs34379100 *C (P<0.01).

^*p-value of haplotype by χ² and Monte Carlo (Number of permutation = 100).