Sequence variation in folate pathway genes and risks of human cleft lip with or without cleft palate.
In an effort to comprehensively interrogate genetic variation in the folate pathway for risk of cleft lip with or without cleft palate (CLP), we evaluated 504 common and rare variants in 35 folate-related genes in a panel of 330 infants with CLP and 367 non-malformed controls. Odds ratios (OR) with 95% confidence intervals were computed for common genotypes. A Case-Control Difference metric was calculated for rare variants to highlight differentially occurring alleles. Interactions between variants and a maternal folate intake variable were also evaluated. In gene-only results, significant odds ratios were observed for multiple variants in the BHMT/BHMT2/DMGDH gene cluster, particularly in Hispanic infants. Also in this cluster, rare variant analysis highlighted a substantial case-control difference in BHMT rs60340837 (synonymous Y284Y). In Hispanics, the ALDH1L1 I812V variant (rs4646750) was the most significant risk allele: OR = 3.8 (95%CI = 1.6-9.2) when heterozygous. In non-Hispanic white infants, we observed significant risk for AHCYL2 rs1095423 (homozygous OR = 3.0, 95%CI 1.1-7.8) and the 68 bp CBS insertion (c.844ins68; heterozygous OR = 2.4, 95%CI = 1.1-5.3). Rare variant analysis in this group revealed case-control differences in MTRR and several other methionine cycle genes, a process implicated previously in clefting risk. In women with low folate intake specifically, increased risks were observed for CBS rs2851391 (OR = 3.6, 95%CI = 1.3-9.6) and the R259P nonsynonymous variant of TCN2 (rs1801198; OR = 2.8, 95%CI = 1.2-6.3). This comprehensive study provides further direction on candidate loci to help disentangle the folate-related developmental phenomena in human clefting risk. © 2016 Wiley Periodicals, Inc.
Department of Molecular and Cellular Biology, California Institute for Quantitative Biosciences, University of California, Berkeley, California. nmarini@berkeley.edu.
Nicholas J
NJ
Marini
Department of Pediatrics, Stanford University School of Medicine, Stanford, California.
Wei
W
Yang
Department of Molecular and Cellular Biology, California Institute for Quantitative Biosciences, University of California, Berkeley, California.
Kripa
K
Asrani
Department of Epidemiology and Biostatistics and Institute of Human Genetics, University of California, San Francisco, California.
John S
JS
Witte
Department of Molecular and Cellular Biology, California Institute for Quantitative Biosciences, University of California, Berkeley, California.
Jasper
J
Rine
UCSF Benioff Children's Hospital Oakland, Oakland, California.
Edward J
EJ
Lammer
Department of Pediatrics, Stanford University School of Medicine, Stanford, California.
Gary M
GM
Shaw
D000483:Alleles; D002140:California / Q000453:epidemiology; D016022:Case-Control Studies; D002971:Cleft Lip / Q000453:epidemiology / Q000235:genetics* / Q000378:metabolism; D002972:Cleft Palate / Q000453:epidemiology / Q000235:genetics* / Q000378:metabolism; D005492:Folic Acid / Q000378:metabolism; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D011159:Population Surveillance; D012306:Risk
D005492:Folic Acid
cleft lip; cleft palate; folate pathway; folic acid; gene-environment interaction; genetic association