Figure 2.
Forest plot showing study-specific estimates for the association between the HLA class II DR3/DR4 genotype and type 1 diabetes (T1D). DR3 = DRB1*03:01-DQA1*05:01-DQB1*02. DR4 = DRB1*04:01/02/04/05/08-DQA1*03:01-DQB1*03:02/04 (or DQB1*02). Total sample size = 5130 T1D cases and 6366 controls from 14 studies. P = 6 × 10[−293] (fixed effects meta-analysis). No significant interstudy heterogeneity was observed: I2 = 13% p(Cochran’s Q) < 0.3 (see [55] for a description of the meta-analysis methods). Case and control genotype counts were derived from the following published studies: Sardinia [65] T1D = 1052, controls = 1917; Italy [66] T1D = 134, controls = 128; USA-HBDI collection [9] T1D = 283, controls = 199; USA-DAISY collection [62,63] T1D = 837, controls = 115; United Kingdom [10] T1D = 753, controls = 753; Sweden [67] T1D = 628, controls = 501; Finland [68] T1D = 622, controls = 622; Hungary [69] T1D = 149, controls = 177; Slovenia [70] T1D = 171, controls = 117; Turkey [71] T1D = 178, controls = 248; Hong Kong [72] T1D = 76, controls = 250; Singapore [71, 73] T1D = 73, controls = 80; Philippines [74] T1D = 90, controls 191; USA Mexican American [75] T1D = 84, controls = 68; For the non-Caucasian studies the control genotype counts were zero, the frequency in controls was estimated as ½ × number of controls. See Thomson et al. [12] for details on study selection criteria. DAISY—Diabetes Autoimmunity in the Young; HBDI—Human Biological Data Interchange.