title: A Polymorphism in the MTRR Gene Is Associated with Early Childhood Caries and Underweight.
abstract: Polymorphisms in genes encoding the enzymes involved in the metabolism of homocysteine, such as methionine synthase (MTR) and methionine synthase reductase (MTRR), play an important function in the metabolism of folic acid and vitamin B12. The present study aimed to evaluate the association of polymorphisms in genes MTR (rs1805087) and MTRR (rs1801394) with susceptibility of early childhood caries (ECC) and with body mass index alterations. A cross-sectional study was performed in 488 children aged from 2 to 6 years from 25 public day care centers in Rio de Janeiro, Brazil. Demographic data and oral health habits were obtained through a questionnaire. Anthropometric measurements and caries experience data were collected by 2 examiners (κ = 0.80). Genotyping of the selected polymorphisms was carried out by TaqMan real-time PCR using genomic DNA extracted from buccal cells. Allele and genotype frequencies were compared between groups with and without disease. The t test, χ2 test, odds ratio, Pearson correlation tests, and logistic regression analysis were used (p ≤ 0.05). The mean white spot lesion score was 1.18 (±2.57) in normal weight children and 2.50 (±3.87) in underweight children (p = 0.05). For MTRR polymorphisms, significant differences were observed for allele and genotype frequency distributions between caries-free and caries-affected children (p = 0.03 and 0.04 for allele and genotype frequencies, respectively) and in the genotype frequencies between normal weight and underweight children (p = 0.04). Our results suggest an association between underweight and ECC; in addition it is suggested that MTRR is a common genetic risk factor for ECC and underweight.
authors.affiliation: Department of Specific Formation, Dental School, Fluminense Federal University, Nova Friburgo, Brazil.
authors.forename: Lívia Azeredo Alves
authors.initials: LA
authors.lastname: Antunes
authors.forename: Claudio Manoel Cabral
authors.initials: CM
authors.lastname: Machado
authors.forename: Ana Carolina Kuntz
authors.initials: AC
authors.lastname: Couto
authors.forename: Ludiana Barbosa
authors.initials: LB
authors.lastname: Lopes
authors.forename: Fernanda Cunha
authors.initials: FC
authors.lastname: Sena
authors.forename: Fernanda Volpe
authors.initials: FV
authors.lastname: Abreu
authors.forename: Renato Silva
authors.initials: RS
authors.lastname: Fraga
authors.forename: Erika Calvano
authors.initials: EC
authors.lastname: Küchler
authors.forename: Leonardo Santos
authors.initials: LS
authors.lastname: Antunes
mesh_terms: D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003731:Dental Caries / Q000235:genetics*; D005260:Female; D005287:Ferredoxin-NADP Reductase / Q000235:genetics*; D006801:Humans; D008297:Male; D020641:Polymorphism, Single Nucleotide; D013851:Thinness / Q000235:genetics*
chemical_list: C111241:methionine synthase reductase; D005287:Ferredoxin-NADP Reductase