[Relationship between folate, vitamin B12, total plasma homocysteine and mutation of reductase].
OBJECTIVE
To study relationship between serum and red blood cell (RBC) folate, serum vitamin B(12) (VB(12)), total plasma homocysteine (tHcy), thermolabile genotypes, and activity of methylene-tetrahydrofolate reductase (MTHFR).


METHODS
Thirty-four non-pregnant and healthy mothers who gave birth to babies with neural tube defects (NTDs) and 42 mothers to normal babies previously were chosen. Plasma tHcy, RBC and serum folate, serum VB(12), activity of MTHFR and thermolabile genotypes were determined for all of them.


RESULTS
There was no significant difference in plasma tHcy, RBC and serun folate between case and control groups. Serum VB(12) was significantly lower in mothers of babies with NTDs than in those with normal ones. Plasma tHcy correlated with RBC folate inversely (P < 0.05). Mean plasma tHcy for thermolabile homozygous mutation of MTHFR was significantly higher than that for either heterozygous mutation or wild homozygous mutation (P < 0.001). There was no significant difference in serum folate between groups with varied MTHFR genotypes. Plasma tHcy was slightly greater in those with lower serum folate than in those with higher one, and correlated inversely with activity of MTHFR.


CONCLUSIONS
Increase in plasma tHcy correlates with homozygous mutation of thermolabile MTHFR and decrease in activity of MTHFR. Higher level of folate in the body can interfere the relationship between plasma tHcy and activity of MTHFR.
Hao
L
L
National Reference Laboratory for Reproductive Health Research, Beijing Medical University, Beijing, 100083, China.
Liu
M
M
Liu
X
X
Chen
X
X
Tang
Y
Y
Li
Z
Z
D000328:Adult; D005260:Female; D005492:Folic Acid / Q000097:blood*; D005838:Genotype; D006710:Homocysteine / Q000097:blood*; D006720:Homozygote; D006801:Humans; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D009436:Neural Tube Defects / Q000209:etiology; D014805:Vitamin B 12 / Q000097:blood*
D006710:Homocysteine; D005492:Folic Acid; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D014805:Vitamin B 12