title: Polymorphisms in the thymidylate synthase and serine hydroxymethyltransferase genes and risk of adult acute lymphocytic leukemia.
abstract: We previously reported that 2 polymorphisms in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene at positions C677T and A1298C were associated with lower risk of adult acute lymphocytic leukemia (ALL). In the present study, we have examined whether polymorphisms in other folate-metabolizing genes play a role in ALL susceptibility. Polymorphisms in methionine synthase (MS A2756G), cytosolic serine hydroxymethyltransferase (SHMT1 C1420T), and a double (2R2R) or triple (3R3R) 28-bp tandem repeat in the promoter region of thymidylate synthase (TS) were studied and found to modulate ALL risk. In a univariate analysis, SHMT1 1420CT individuals exhibited a 2.1-fold decrease in ALL risk (odds ratio [OR] = 0.48; 95% confidence interval [CI], 0.25-0.91), whereas the 1420TT genotype conferred a 3.3-fold reduction in risk (OR = 0.31; 95% CI, 0.10-0.90). Similarly, TS 2R3R individuals exhibited a 2.8-fold reduction in ALL risk (OR = 0.36; 95% CI: 0.16-0.83), while the TS 3R3R genotype conferred an even greater level of protection (OR = 0.25; 95% CI, 0.08-0.78). However, no significant associations were evident for the MS 2756AG polymorphism (OR = 0.79; 95% CI, 0.38-1.7). In addition, potential interactions between the SHMT1 and TS or MS genes were observed. TS 3R3R individuals who were SHMT1 1420CT/TT had a 13.9-fold decreased ALL risk (OR = 0.072; 95% CI, 0.0067-0.77). Further, MS 2756AG individuals who were SHMT1 1420CT/TT had a 5.6-fold reduction in ALL risk (OR = 0.18; 95% CI, 0.05-0.63). This study suggests an important role for uracil misincorporation and resultant chromosomal damage in the pathogenesis of ALL, and that genetic interactions involving low penetrance polymorphisms in folate-metabolizing genes may increase ALL risk.
authors: NFCR Center for Genomics and Nutrition, School of Public Health, and the Department of Nutritional Sciences, University of California, Berkeley, CA 94720-7360, USA.
authors: Christine F
authors: CF
authors: Skibola
authors: Martyn T
authors: MT
authors: Smith
authors: Alan
authors: A
authors: Hubbard
authors: Barry
authors: B
authors: Shane
authors: Abby C
authors: AC
authors: Roberts
authors: Graham R
authors: GR
authors: Law
authors: Sara
authors: S
authors: Rollinson
authors: Eve
authors: E
authors: Roman
authors: Raymond A
authors: RA
authors: Cartwright
authors: Gareth J
authors: GJ
authors: Morgan
mesh_terms: D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase / Q000235:genetics; D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D005492:Folic Acid / Q000378:metabolism; D020022:Genetic Predisposition to Disease; D005838:Genotype; D012696:Glycine Hydroxymethyltransferase / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008956:Models, Chemical; D015999:Multivariate Analysis; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000201:enzymology / Q000235:genetics*; D013940:Thymidylate Synthase / Q000235:genetics*
chemical_list: D005492:Folic Acid; D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase; D013940:Thymidylate Synthase; D012696:Glycine Hydroxymethyltransferase