International Union for Circumpolar Health Ministry of Public Health and Social Development of RF Russian Academy of Medical Sciences Siberian Branch of Russian Academy of Medical Sciences Siberian Branch of Russian Academy of Sciences Medical Polar Fund “Science” The Northern Forum

Abstracts

Genetics, demography, anthropology

There is interest that not only neural tube defects (NTDs) but other common birth defects such as heart defects, might be reduced with folic acid supplementation or fortification. Although NTDs are not more frequent in the Inuit of the Eastern Arctic, septal heart defects were documented pre-fortification (1989-1994) to be increased 4 fold. In 1998 folic acid fortification of grain products was initiated in Canada in an amount projected to raise daily intake by ≈100 μg/day. Of concern for those in the North is that on the background of a presumed low folate diet (poor availability of folate rich foods) this amount might be insufficient to elevate cellular folate to a level that will reduce birth defects (estimated at 900nmol/L).

Objectives: To determine if current efforts of fortification are sufficient and to explore other genetic/environmental determinants of the increased rate of septal heart defects in the Eastern Arctic. Methods: Inuit mothers of children from communities on Baffin Island with and without heart defects were invited to participate in a case control study evaluating nutrient intake, pregnancy exposures, RBC folate, serum cobalamin, homocysteine, and four functional polymorphisms for genes important in folate metabolism and uptake (MTHFR A222V, E429A, MTRR I22M and RCF-1 H27R).

Results: 41 children with isolated heart defects and their mothers with 36 community matched Inuit controls have entered the study to date. Results: There were no differences in RBC folate (953 Vs 922 nmol/L p=.49), serum cobalamin, and homocysteine, between mothers of cases and controls. The combined average RBC folate for the women ages 18-45 was 947 +/- 32 nmol/L. There was no difference between any documented alcohol (≈30%) and cigarette (≈82%) use in pregnancy. No Inuit women were taking vitamins at conception nor at the time of this study. Preliminary data suggests that one genetic polymorphism (RFC-1), important for absorption of folate may be associated with heart defects. Conclusions: RBC folate (post-fortification) in our sample of women of childbearing years is reassuring. However, it is possible that pre-fortification levels combined with genetic predisposition may have influenced the high rate of heart defects. Follow-up study is underway to determine if rates of heart defects have therefore decreased since fortification was commenced.

Note. Abstracts are published in author's edition

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Last update: 06-Jul-2012 (11:52:05)