Maternal polymorphisms in folic acid metabolic genes are associated with nonsyndromic cleft lip and/or palate in the Brazilian population.
BACKGROUND
Polymorphisms in genes that are involved in folic acid metabolism may be important maternal risk factors for the birth of a child with nonsyndromic cleft lip and/or palate (NSCL/P). The aim of this study was to determine the involvement of polymorphic variants in four genes (MTHFR, MTHFD1, MTR, and SLC19A1) that encode proteins related to folic acid metabolism in the women with susceptibility for having a child with NSCL/P.


METHODS
DNA samples from 106 mothers of children with NSCL/P (case group) and from 184 mothers of healthy children (control group) were genotyped by polymerase chain reaction associated with restriction fragment length polymorphism (PCR-RFLP).


RESULTS
One of 29 polymorphisms was associated with significantly increased maternal risk for NSCL/P. Mothers exhibiting the A variant allele (GA genotype) of the MTHFR rs2274976 polymorphism demonstrated a ~6 times increased risk for having a child with NSCL/P compared to G allele carriers (OR, 5.76; 95% CI, 3.32-9.99, p = 0.000001). Among mothers who did not use vitamins, the OR of NSCL/P was increased to 8.34 (95% CI, 3.75-18.55, p = 0.000001) in the presence of the GA genotype of the MTHFR rs2274976 polymorphism compared to those with the GG genotype. Gene-gene interaction analysis showed that the combination of MTHFR rs2274976, MTHFD1 rs2236225, and SLC19A1 rs1051266 was the best model for prediction of maternal risk for NSCL/P.


CONCLUSIONS
The findings of the present study suggested that genetic variants of folic acid metabolic genes may modulate maternal susceptibility for having an offspring with NSCL/P.
Bufalino
Andreia
A
Department of Oral Diagnosis, School of Dentistry, State University of Campinas, Piracicaba, São Paulo, Brazil.
Ribeiro Paranaíba
Lívia Máris
LM
Nascimento de Aquino
Sibele
S
Martelli-Júnior
Hercílio
H
Oliveira Swerts
Mario Sergio
MS
Coletta
Ricardo D
RD
D000293:Adolescent; D000328:Adult; D001938:Brazil; D016022:Case-Control Studies; D002971:Cleft Lip / Q000235:genetics*; D002972:Cleft Palate / Q000235:genetics*; D005260:Female; D005492:Folic Acid / Q000378:metabolism*; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008754:Methylenetetrahydrofolate Dehydrogenase (NADP) / Q000235:genetics; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D015778:Minor Histocompatibility Antigens; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D011247:Pregnancy; D058978:Reduced Folate Carrier Protein / Q000235:genetics; D012307:Risk Factors; D055815:Young Adult
D015778:Minor Histocompatibility Antigens; D058978:Reduced Folate Carrier Protein; C548699:SLC19A1 protein, human; D005492:Folic Acid; D042965:Methylenetetrahydrofolate Reductase (NADPH2); C539735:MTHFD1 protein, human; D008754:Methylenetetrahydrofolate Dehydrogenase (NADP)