Genetic polymorphisms in the Hmong population: implications for cancer etiology and survival.
BACKGROUND
The Hmong, an isolated, agrarian people from southern China, migrated to the mountainous regions of what are today Vietnam, Cambodia, and Laos. Minnesota has the second largest Hmong population in the United States. The authors compared frequencies of common genetic polymorphisms believed to influence risk of malignancy to determine whether frequencies in the Hmong are different from those in other Asian populations and in white Minnesotans.


METHODS
Genotyping for glutathione S-transferase micro1 (GSTM1), glutathione S-transferase theta1 (GSTT1), myeloperoxidase (MPO) (C(-)463T), nicotinamide adenine dinucleotide phosphate:quinone oxidoreductase (NQO1) (C609T), 5,10-methylenetetrahydrofolate reductase (MTHFR) (C677T), MTHFR (A1298C), methionine synthase reductase (MTRR) (A66G), X-ray repair cross complementing 1 (XRCC1) 194 (Arg194Trp), XRCC1 280 (Arg280His), and XRCC1 399 (Arg399Gln) alleles was performed by TaqMan analysis using DNA isolated from newborn heel-stick spots provided by the Minnesota Department of Health.


RESULTS
The Hmong had significantly higher frequencies of the NQO1 T allele and the XRCC1 Trp polymorphism (Arg194Trp) and had significantly lower frequencies of the G allele in MTRR (A66G) and the T allele in MTHFR (C677T) compared with white Minnesotans. The Hmong also were significantly more likely to lack the GSTM1 and GSTT1 genes compared with whites (82% vs. 54% and 61% vs. 18%, respectively). Genotype frequencies were similar for MTHFR (A1298C), MPO (C(-)463T), and XRCC1 (Arg280His, Arg399Gln). Genotype frequencies at these loci also were compared with those reported for other Asian populations and showed notable differences between the Hmong and Chinese/Taiwanese, Korean, and Japanese populations.


CONCLUSIONS
The genetic differences identified have implications for both cancer etiology and prognosis in this unique population.
Kiffmeyer
William R
WR
Department of Pediatrics, University of Minnesota Cancer Center, 420 Delaware Street SE, Minneapolis, MN 55455, USA.
Langer
Erica
E
Davies
Stella M
SM
Envall
Julie
J
Robison
Leslie L
LL
Ross
Julie A
JA
D001208:Asia; D002160:Cambodia / Q000208:ethnology; D004260:DNA Repair; D005260:Female; D005287:Ferredoxin-NADP Reductase / Q000235:genetics; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005982:Glutathione Transferase / Q000235:genetics; D006801:Humans; D007231:Infant, Newborn; D007812:Laos / Q000208:ethnology; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics; D008910:Minnesota; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000235:genetics; D009369:Neoplasms / Q000235:genetics*; D009195:Peroxidase / Q000235:genetics; D011110:Polymorphism, Genetic; D014744:Vietnam / Q000208:ethnology; D044465:White People
D009195:Peroxidase; C111241:methionine synthase reductase; D005287:Ferredoxin-NADP Reductase; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D016660:NAD(P)H Dehydrogenase (Quinone); D005982:Glutathione Transferase