title: Genetic variation in the sodium-dependent vitamin C transporters, SLC23A1, and SLC23A2 and risk for preterm delivery.
abstract: Vitamin C has been the focus of epidemiologic investigation in preterm delivery (<37 weeks' gestation), which is a leading cause of neonatal mortality and birth-related morbidity. There are two sodium-dependent membrane transporters encoded by SLC23A1 and SLC23A2, which have key roles in human vitamin C metabolism and which control dietary uptake, reabsorption, and tissue distribution of vitamin C. Using maternal DNA, the authors evaluated common single-nucleotide polymorphisms (SNPs) in SLC23A1 and SLC23A2 in a nested case-control analysis of the Pregnancy, Infection, and Nutrition Study (1995-2000) cohort. Of the associations observed for both haplotypes in SLC23A1 and individual SNPs in SLC23A2, the most robust finding is with an intron 2 variant in SLC23A2. Heterozygotes and homozygotes for this variant had a 1.7-fold (95% confidence interval: 0.9, 3.3) and a 2.7-fold (95% confidence interval: 1.2, 6.3) elevation in the risk of spontaneous preterm birth, respectively. Semi-Bayesian hierarchical regression analysis, which simultaneously adjusted for multiple SNPs within the same gene, gave comparable results. The authors' findings link genetic variants in the vitamin C transporters to spontaneous preterm birth, which may explain previous dietary associations. If the findings from this study are confirmed, they may serve as the foundation for genetic risk assessment of nutritional pathways in preterm birth.
authors.affiliation: Section on Genomic Variation, Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA.
authors.forename: Hans Christian
authors.initials: HC
authors.lastname: Erichsen
authors.forename: Stephanie A Mulherin
authors.initials: SA
authors.lastname: Engel
authors.forename: Peter K
authors.initials: PK
authors.lastname: Eck
authors.forename: Robert
authors.initials: R
authors.lastname: Welch
authors.forename: Meredith
authors.initials: M
authors.lastname: Yeager
authors.forename: Mark
authors.initials: M
authors.lastname: Levine
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Siega-Riz
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Olshan
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Chanock
mesh_terms: D000328:Adult; D001741:Black or African American / Q000235:genetics; D000483:Alleles; D001205:Ascorbic Acid / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D014644:Genetic Variation; D006239:Haplotypes; D006801:Humans; D009657:North Carolina; D029363:Organic Anion Transporters, Sodium-Dependent / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D011247:Pregnancy; D047928:Premature Birth / Q000235:genetics*; D012307:Risk Factors; D060347:Sodium-Coupled Vitamin C Transporters; D027981:Symporters / Q000235:genetics*; D044465:White People / Q000235:genetics
chemical_list: D029363:Organic Anion Transporters, Sodium-Dependent; C555162:SLC23A1 protein, human; C555163:SLC23A2 protein, human; D060347:Sodium-Coupled Vitamin C Transporters; D027981:Symporters; D001205:Ascorbic Acid