CHKA and PCYT1A gene polymorphisms, choline intake and spina bifida risk in a California population.
BACKGROUND
Neural tube defects (NTDs) are among the most common of all human congenital defects. Over the last two decades, accumulating evidence has made it clear that periconceptional intake of folic acid can significantly reduce the risk of NTD affected pregnancies. This beneficial effect may be related to the ability of folates to donate methyl groups for critical physiological reactions. Choline is an essential nutrient and it is also a methyl donor critical for the maintenance of cell membrane integrity and methyl metabolism. Perturbations in choline metabolism in vitro have been shown to induce NTDs in mouse embryos.


METHODS
This study investigated whether single nucleotide polymorphisms (SNPs) in human choline kinase A (CHKA) gene and CTP:phosphocholine cytidylytransferase (PCYT1A) gene were risk factors for spina bifida. Fluorescence-based allelic discrimination analysis was performed for the two CHKA intronic SNPs hCV1562388 (rs7928739) and hCV1562393, and PCYT1A SNP rs939883 and rs3772109. The study population consisted of 103 infants with spina bifida and 338 non-malformed control infants who were born in selected California counties in the period 1989-1991.


RESULTS
The CHKA SNP hCV1562388 genotypes with at least one C allele were associated with a reduced risk of spina bifida (odds ratio = 0.60, 95%CI = 0.38-0.94). The PCYT1A SNP rs939883 genotype AA was associated with a twofold increased risk of spina bifida (odds ratio = 1.89, 95% CI = 0.97-3.67). These gene-only effects were not substantially modified by analytic consideration to maternal periconceptional choline intake.


CONCLUSIONS
Our analyses showed genotype effects of CHKA and PCYT1A genes on spina bifida risk, but did not show evidence of gene-nutrient interactions. The underlying mechanisms are yet to be resolved.
Enaw
James O Ebot
JO
Center for Environmental and Genetic Medicine, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, Houston, Texas 77030, USA. oenaw@yahoo.co.uk
Zhu
Huiping
H
Yang
Wei
W
Lu
Wei
W
Shaw
Gary M
GM
Lammer
Edward J
EJ
Finnell
Richard H
RH
D002140:California / Q000453:epidemiology; D002794:Choline / Q000378:metabolism*; D002797:Choline Kinase / Q000235:genetics*; D019916:Choline-Phosphate Cytidylyltransferase / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D007438:Introns; D009436:Neural Tube Defects / Q000453:epidemiology; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide; D011247:Pregnancy; D016135:Spinal Dysraphism / Q000453:epidemiology* / Q000235:genetics*
C517212:CHKA protein, human; D002797:Choline Kinase; D019916:Choline-Phosphate Cytidylyltransferase; C517213:PCYT1A protein, human; D002794:Choline