Table 3 Estimated haplotype frequencies of the MTHFR 677C→T and 1298A→C single nucleotide polymorphisms.

Haplotype		Cases (%)		Mothers (%)		Fathers (%)		All
677C – 1298A		44.6		41.9		40.7		42.0%
677C – 1298C		24.0		27.0		28.7		25.5%
677T – 1298A		31.2		31.1		30.3		30.9%
677T – 1298C		0.3		0.0		0.3		1.6%

MTHFR, methylenetetrahydrofolate reductase.