AIN To study the relationship of Imp2 and DR3genes with type Ⅰ diabetes mellitus.NETHODS Imp2 genotypes and DR3 wereidentified in 68 patients with type Ⅰ diabetesmellitus(Ⅰ-DM)and 71 healthy controls.Then,Ⅰ-DM patients and controls were respectivelyallocated into DR3-positive and DR3-negativegroups.The frequencies of Imp2 and DR3 genein random subjects,and Imp2 genotypes in DR3-matched subjects were compared between Ⅰ-DMpatients and controls.At the same time,Ⅰ-DMpatients were divided into 3 groups based on theonset age of diabetics:group A≤14 years,group B 15-30 years and group C≥31 years.RESULTS The frequency of DR3 in Ⅰ-DMpatients was significantly higher than that incontrols(47% vs 21%,P<0.005),and it wassignificantly higher in group A than that in groupB+C(70% vs 36%,x~2=7.07,P<0.01).Therewas a significant difference among groups withdifferent onset age of diabetics(x~2=8.19,rp=0.33,P<0.05).In random subjects,thefrequency of Imp2.R/R in Ⅰ-DM patients waslower(43% vs 61%,P<0.05)and Imp2.R/Hhigher(53% vs 28%,P<0.05)than that incontrols,and there was no significant differenceamong groups with different onset age ofdiabetics.In DR3-positive subjects,thefrequency of Imp2.R/R in Ⅰ-DM patients waslower(47% vs 87%,P<0.05)and Imp2-R/H higher(47% vs 13%,P<0.05)than that incontrols.In DR3-negative subjects,thefrequency of Imp2.R/H in Ⅰ-DM patients washigher than that in controls(58% vs 32%,P<0.01),but the frequency of Imp2-R/R and Imp2H/H was not significantly different betweenthese two groups.CONCLUSION DR3 gene may be one of thesusceptible genes of Ⅰ-DM,and significantlyrelated to the onset age of diabetics,and thepersons with DR3 may have an younger onsetage of diabeteS.The Imp2-R/R may be theprotective genotype of Ⅰ-DM,and Imp2-R/H thesusceptible genotype.These were not affectedby DR3 gene.Imp-2 genotypes were not relatedwith the onset age of diabetics. AIN To study the relationship of Imp2 and DR3genes with type I diabetes mellitus.NETHODS Imp2 genotypes and DR3 were identified in 68 patients with type I diabetes mellitus (I-DM) and 71 healthy controls. Then, I-DM patients and controls were respectively assigned into DR3 -positive and DR3-negativegroups.The frequencies of Imp2 and DR3 genein random subjects, and Imp2 genotypes in DR3-matched subjects were compared between I-DMpatients and controls. At the same time, I-DMpatients were divided into 3 groups based on theonset age of diabetics: group A ≤ 14 years, group B 15-30 years and group C ≧ 31 years .RESULTS The frequency of DR3 in I-DM patients was significantly higher than that incontrols (47% vs 21%, P <0.005) and it wassignificantly higher in group A than that in group B + C (70% vs 36%, x ~ 2 = 7.07, P <0.01) .here was a significant difference among groups with different onset age of diabetics (x ~ 2 = 8.19, rp = 0.33, P <0.05) .In random subjects, the frequency of Imp2.R / R in I-DM patients waslower (43 % vs 61%, P <0.05) and Imp2.R / Hhigher (53% vs 28%, P <0.05) than that incontrols, and there was no significant differenceamong groups with different onset age of diabetics.In DR3-positive subjects, the frequency of Imp2.R / R in I-DM patients waslower (47% vs 87%, P <0.05) and Imp2-R / H higher (47% vs 13%, P <0.05) than that incontrol , the frequency of Imp2.R / H in I-DM patients washigher than that in controls (58% vs 32%, P <0.01), but the frequency of Imp2-R / R and Imp2H / H was not significantly different between two groups .CONCLUSION DR3 gene may be one of the susceptible genes of I-DM, and significantly associated with the onset age of diabetics, and the persons with DR3 may have an younger on stage of diabeteS. The Imp2-R / R may be the PROTECTIVE genotype of I-DM , and Imp2-R / H the susceptible genotype. These were not affected by DR3 gene. Int-2 genotypes were not related with the onset age of diabetics.