TABLE 3

Age at diagnosis in all 1,384 autoimmune diabetic case subjects, irrespective of age at diagnosis, by HLA genotype (rs9271366 being too rare to analyze for age-at-diagnosis effects by age category)

Mean age at diagnosis (years) (SD)Genotype counts (frequency) by age-groupPPcat
0–21 years22–31 years32–43 years≥44 years
rs660895 (DR4)
 A/A (X/X)35.8 (16.4)97 (0.30)104 (0.33)130 (0.41)133 (0.44)4.67 × 10−62.58 × 10−4
 G/A (4/X)32.3 (15.5)172 (0.53)174 (0.54)146 (0.46)146 (0.48)
 G/G (4/4)30.0 (14.7)54 (0.17)42 (0.13)41 (0.13)27 (0.09)
rs2187668 (DR3)
 G/G (X/X)34.0 (16.3)187 (0.56)176 (0.55)177 (0.56)187 (0.61)0.0670.51
 G/A (3/X)31.9 (15.3)128 (0.38)126 (0.39)118 (0.37)104 (0.34)
 A/A (3/3)32.9 (13.0)18 (0.05)20 (0.06)21 (0.07)17 (0.06)
rs9271366 (DR15)
 A/A (X/X)33.1 (15.9)320 (0.98)307 (0.96)298 (0.95)297 (0.96)0.13NA
 A/G (15/X)36.7 (11.1)4 (0.01)12 (0.04)15 (0.05)13 (0.04)
 G/G (15/15)37.3 (18.2)1 (0.00)0 (0.00)1 (0.00)1 (0.00)
 3/333.3 (12.9)16 (0.05)20 (0.06)21 (0.07)17 (0.06)1.78 × 10−70.0029
 3/430.4 (14.4)72 (0.23)73 (0.23)57 (0.18)50 (0.17)
 4/430.0 (14.3)54 (0.17)41 (0.13)40 (0.13)27 (0.09)
 3/X33.9 (16.3)51 (0.16)49 (0.16)59 (0.19)50 (0.17)
 4/X33.4 (16.1)98 (0.31)99 (0.31)85 (0.28)92 (0.31)
 X/X39.2 (17.3)26 (0.08)33 (0.10)47 (0.15)60 (0.20)
  • NA, not analyzed. P, the P value for interaction of age at diagnosis as a continuous trait with genotype. Pcat, P value for interaction of genotype with the four age-groups corresponding to the quartiles of the age-at-diagnosis distribution.