Association of CD40 gene polymorphism (C-1T) with susceptibility and phenotype of Graves' disease.

OBJECTIVE

Recently, a functional polymorphism in the CD40 gene at position -1, C to T change (C-1T) has been identified and the C/C genotype has been reported to be associated with Graves' disease (GD).

DESIGN

We performed a case-control, replication study on 556 patients with GD and 611 healthy subjects in a Polish population. Furthermore, we analyzed the distribution of CD40 genotypes in subgroups of patients with GD divided according to age of onset, gender, family history, tobacco smoking, ophthalmopathy, and genetic parameters (CTLA4 49G, PTPN22/LYP 1858T or HLA-DRB1*03 alleles).

RESULTS

Although the frequency of C/C genotype was increased in GD compared to controls, the difference was not significant (60.5% versus 55.8%, p = 0.062, odds ratio [OR] = 1.21, 95% confidence interval [CI]: 0.96-1.53). Because our study was underpowered to detect such a modest association, we performed a meta-analysis with the data from previous studies. The combined OR for the C/C genotype as a risk factor for GD was 1.22 (95% CI: 1.08-1.38, p = 0.001). We failed to find an interaction between CD40 genotypes and other GD susceptibility alleles. No significant genotype-phenotype associations were found.

CONCLUSIONS

Our results support the notion that CD40 C-1T polymorphism has a modest effect on genetic susceptibility to sporadic GD.