Table 3.

Genotype and Haplotype frequencies for ERAP2, MTHFR, and COMT for African American samples.

				Minor Allele Frequency
Group	Gene	SNP/Haplotype	Minor Allele	Pennsylvania	Michigan
Maternal	ERAP2	rs2549782	G	0.397	0.374
	MTHFR	rs1801133	T	0.112	0.102
	COMT	rs6269	G	0.393	0.384
		rs4633	T	0.292	0.316
		rs4818	G	0.200	0.215
		rs4680	A	0.276	0.291
		ATCA		0.249	0.270
		GCCA		0.027	0.021
		GCGG		0.163	0.169
		ACGG		0.037	0.048
		ATCG		0.043	0.045
		GCCG		0.203	0.194
		ACCG		0.278	0.253
Fetal	ERAP2	rs2549782	G	0.359	0.424
	MTHFR	rs1801133	T	0.120	0.133
	COMT	rs6269	G	0.408	0.425
		rs4633	T	0.319	0.300
		rs4818	G	0.214	0.167
		rs4680	A	0.292	0.308
		ATCA		0.267	0.257
		GCCA		0.022	0.051
		GCGG		0.175	0.139
		ACGG		0.040	0.028
		ATCG		0.049	0.043
		GCCG		0.207	0.235
		ACCG		0.240	0.247

African American samples originated from two locations: the University of Pennsylvania Medical Center, PA and Hutzel Women's Hospital, MI. Minor allele frequencies and haplotype frequencies were calculated from control samples only at each location. When comparing locations, no test achieved a significant difference at the 5% level using a Z-test for differences in two independent proportions. SNP, single nucleotide polymorphism. COMT single SNP frequencies are listed first, followed by COMT haplotypes formed by those SNPs. COMT haplotype SNP order: rs6269, rs4633, rs4818, rs4680.