Table 1.

Characteristics and genotype frequencies of the folate gene polymorphisms analyzed in this study among cases and controls

Gene/SNP*LocationAA changeMinor alleleMinor allele frequency
P
CasesControls
MTHFR
    rs1801133 (C677T)Exon 5Val → AlaT35.232.70.24
    rs1801131 (A1298C)Exon 8Ala → GluC31.628.50.14
    rs2066470 (T118C)Exon 2NoneT10.07.80.094
MTR
    rs1806505 (C/T)Intron 13NAT40.843.00.26
    rs1805087 (A2756G)Exon 26Asp → GlyG18.117.90.91
    rs1050993 (G/A)3′ UTRNAA38.135.40.21
MTRR
    rs1801394 (A66G)Exon 2Met → IleA43.343.60.90
    rs10380 (C1785T)Exon 14Tyr → HisT8.710.10.29
SHMT1
    rs643333 (C/A)5′ UTRNAA29.128.90.90
    rs2273028 (C/T)Intron 7NAT31.232.20.66
    rs1979277 (C1420T)Exon 12Leu → PheA31.031.20.92
MTHFD1
    rs1076991 (A/G)5′ UTRNAG45.846.50.76
    rs1950902 (R134K)Exon 6Arg → LysT19.215.80.048
    rs2236224 (C/T)Intron 21NAT38.441.00.24
    rs2236225 (R653Q)Exon 21Arg → GlnT43.145.40.30
TYMS
    rs502396 (T/C)Intro 1NAC48.749.80.56
    rs699517 (C/T)3′ UTRNAT33.533.30.91
    28-bp Tandem repeat5′ UTRNA2r48.448.50.97
DHFR
    rs1677693 (C/A)Intron 3NAA26.427.10.71
    rs1643638 (T/C)Intron 4NAC26.227.50.52
FTHFD (ALDH1L1)
    rs2276731 (T/C)Intron 4NAC20.416.40.022
    rs2002287 (T/C)Intron 13NAC34.238.80.034
    rs1127717 (A2380C)Exon 21Asp → GlyG18.919.60.70
CBS
    rs234706 (Y233Y)Exon 8NoneA34.731.40.12
    rs1801181 (A360A)Exon 12NoneT32.436.90.040
  • Abbreviations: NA, not available; UTR, untranslated region.

  • * The designation by which the SNP is commonly referred to in the literature, when one exists, is shown in parenthesis.

  • P for the difference in minor allele frequencies was determined using the χ2 test with 1 degree of freedom.