Table 3. Allele frequencies in cases and controls and odds ratio estimates for non-traumatic ONFH.

SNP	Gene	Locus	Alleles (A/B)	MAF		HWE pa value	ORs	95%CI	pb Value
				Case	Control
rs3918249	MMP9	20q13.12	T/C	0.297	0.322	0.613	0.886	0.739-1.062	0.191
rs2274755	MMP9	20q13.12	T/G	0.116	0.151	0.729	0.740	0.578-0.949	0.017*
rs3918254	MMP9	20q13.12	T/C	0.203	0.187	0.664	1.102	0.891-1.363	0.372
rs1053605	MMP2	16q12.2	T/C	0.112	0.129	0.843	0.850	0.656-1.100	0.217
rs243849	MMP2	16q12.2	T/C	0.191	0.167	1.00	1.177	0.945-1.468	0.146
rs243847	MMP2	16q12.2	C/T	0.415	0.405	0.117	1.042	0.879-1.237	0.634
rs243832	MMP2	16q12.2	C/G	0.362	0.382	0.347	0.921	0.774-1.096	0.353
rs7201	MMP2	16q12.2	C/A	0.245	0.255	0.349	0.950	0.782-1.154	0.603

SNP: single nucleotide polymorphism, HWE: Hardy-Weinberg equilibrium, OR: odds ratio, 95% CI: 95% confidence interval, MAF: minor allele frequency.

^ap was calculated by fisher's exact test.

^bp was calculated by Pearson Chi-squared test.

A/B=minor/major alleles.

The SNPs were excluded at HWE P level of 5%.