Table II.

Estimated Haplotype Frequencies in Irish Controls, NTD Cases and NTD Mothers

	Haplotype	Control frequency*	NTD case frequency*	NTD mother frequency*
Block 1	G-G	0.897	0.899	0.882
	C-A	0.072	0.064	0.081
	C-G	0.029	0.033	0.035
			p**=0.73	p**=0.09
Block 2	G-A-G-G-C	0.725	0.723	0.723
	C-C-C-A-C	0.105	0.084	0.088
	C-A-C-G-C	0.069	0.069	0.075
	C-A-C-G-T	0.065	0.059	0.064
	G-C-G-G-C	0.015	0.021	0.023
	C-C-C-A-T	0.010	0.014	0.008
			p**=0.63	p**=0.50

Haplotype blocks are defined as shown in Figure 1b: Block 1 (rs8064946, rs2078486); Block 2 (rs1642785, rs17878362, rs1042522, rs1625895, rs6503048).

^*Haplotype frequencies were estimated using Phase 2.1 as described in the Materials and Methods. Haplotypes with a frequency <0.01 are omitted so columns do not to sum to 1.

^**Result of permutation test for significant differences in haplotype frequencies in NTD cases vs. controls or NTD mothers vs. controls.