Heterogeneity in the prevalence of methylenetetrahydrofolate reductase gene polymorphisms in women of different ethnic groups.
OBJECTIVE
To determine the prevalence of methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms in women of different ethnic groups and to relate these common mutations to plasma homocysteine, red cell folate, and serum folate.


METHODS
A one-time fasting blood sample was obtained for MTHFR genotype (C677T and A1298C) determinations (n=433). Serum folate, red cell folate, and homocysteine analyses were performed in nonfolic acid supplement users (n=215).


METHODS
This study involved 433 women from four ethnic groups, including 193 Hispanic women of Mexican descent, 139 white women, 53 Asian women of mixed descent, and 48 African American women. STATISTICAL ANALYSIS PREFORMED: Chi;(2), t Test, and analysis of variance were used.


RESULTS
Mexican women (18.1%) had a higher frequency of the 677 TT genotype compared with white (7.2%), Asian (3.8%), and African American (0%) women. White women (7.9%) had a higher frequency of the 1298 CC genotype than the other ethnic groups (range=1.9% to 2.6%). The frequency of compound heterozygosity (677 CT + 1298 AC) was higher in Mexican (17.6%) and white (15.1%) women than Asian and African American ( approximately 4% to 6%) women. In the era of folic acid fortification, neither genotype, independently or together, was associated with homocysteine or blood folate concentrations when ethnic groups were combined. In Mexican women, however, a linear trend (P</=.05) was detected for the C677T variants with the lowest red cell folate in the TT genotype.


CONCLUSIONS
These data demonstrate ethnic differences in genetic polymorphisms that are diet responsive and may be useful when investigating ethnic variations in chronic disease, developmental anomalies, and folate requirements.
Esfahani
Setareh Torabian
ST
Agricultural Sciences in the Human Nutrition and Food Science Department, Cal Poly Pomona University, Pomona, CA 91768, USA.
Cogger
Edward A
EA
Caudill
Marie A
MA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001213:Asian / Q000235:genetics; D044466:Asian People / Q000235:genetics; D044383:Black People / Q000235:genetics; D005006:Ethnicity / Q000235:genetics* / Q000706:statistics & numerical data; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000097:blood*; D005787:Gene Frequency; D018740:Genetic Heterogeneity; D005838:Genotype; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D017058:Mexican Americans / Q000235:genetics; D008875:Middle Aged; D009154:Mutation; D009751:Nutritional Requirements; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics*; D011110:Polymorphism, Genetic; D015995:Prevalence; D044469:Racial Groups / Q000235:genetics*; D044465:White People / Q000235:genetics; D001741:Black or African American
D006710:Homocysteine; D005492:Folic Acid; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2)