Table 2

 Number and frequency of methylenetetrahydrofolate reductase gene single-nucleotide polymorphism genotypes in Causasians and African-Americans with rheumatoid arthritis and controls

SNP genotypeAfrican-Americans with RA (n = 138)Caucasians with RA (n = 393)African-American controls (n = 53)Caucasian controls (n = 50)
RA, rheumatoid arthritis; SNP, single-nucleotide polymorphism.
Caucasians with rheumatoid arthritis were from the Iowa rheumatoid arthritis cohort (n = 200),19 the University of Alabama at Birmingham folate trial in rheumatoid arthritis (n = 59)20 and the Immunex rheumatoid arthritis trial (n = 134).21 African-Americans with rheumatoid arthritis were from the Grady African-American Rheumatoid Arthritis (GAARA) cohort (n = 108),18 the aforementioned folate trial (n = 18) and Immunex trial (n = 12). *In all, 102 subjects from GAARA were genotyped at the rs2274976 GA SNP; 52 African-American controls were genotyped at the 677 CT SNP and 51 subjects at the rs2274976 GA SNP.
    677 CC109 (0.79)196 (0.50)39 (0.75)*25 (0.50)
    CT27 (0.20)157 (0.40)12 (0.23)22 (0.44)
    TT2 (0.01)40 (0.10)1 (0.02)3 (0.06)
rs2066462 CC117 (0.85)320 (0.81)42 (0.79)37 (0.74)
    CT21 (0.15)68 (0.18)10 (0.19)13 (0.26)
    TT05 (0.01)1 (0.02)0
    1298 AA102 (0.74)178 (0.45)36 (0.68)25 (0.50)
    AC35 (0.25)165 (0.42)16 (0.30)19 (0.38)
    CC1 (0.01)50 (0.13)1 (0.02)6 (0.12)
rs4846051 TT63 (0.46)387 (0.98)25 (0.47)49 (0.98)
    TC60 (0.43)6 (0.02)23 (0.43)1 (0.02)
    CC15 (0.11)05 (0.09)0
rs2274976 GG123 (0.93) *355 (0.90)43 (0.84) *46 (0.92)
    GA9 (0.07)37 (0.09)8 (0.16)4 (0.08)
    AA01 (0.002)00