A promoter polymorphism of the CYP27B1 gene is associated with Addison's disease, Hashimoto's thyroiditis, Grave's disease and type 1 diabetes mellitus in Germans

Abstract

Background: CYP27B1 hydroxylase catalyzes the conversion of 25 hydroxyvitamin D3 (250HD3) to 1,25(OH 2D3, the most active natural vitamin D metabolite, which plays a role in the regulation of immunity and cell proliferation. We therefore investigated two single nucleotide polymorphisms in the CYP27B1 hydroxylase gene for an association with Addison's disease, Hashimoto's thyroiditis, Graves' disease and type 1 diabetes mellitus. Methods: Patients with Addison's disease (n = 124), Hashimoto's thyroiditis (n = 139), Graves' disease (n = 334), type 1 diabetes mellitus (n = 252) and healthy controls (n = 320) were genotyped for the promoter (-1260) C/A polymorphism and for the intron 6 (+2838) C/T polymorphism of the CYP27B1 gene. Patients and controls were compared using genotype-wise and allele-wise X2 testing. Results: A significant association was found between allelic variation of the promoter (-1260) C/A polymorphism and Addison's disease, Hashimoto's thyroiditis, Graves' disease and type 1 diabetes mellitus (P = 0.0062, P = 0.0173, P = 0.0094 and P = 0.0028 respectively). Significant differences were also observed for the intron 6 (+2838) C/T polymorphism (P = 0.0058) in Hashimoto's thyroiditis but not for the other autoimmune endocrine diseases. Conclusions: The CYP27B1 promoter (-1260) C/A polymorphism appears to be associated with endocrine autoimmune diseases but the CYP27B1 intron 6 (+2838) C/T polymorphism appears to be associated only with Hashimoto's thyroiditis. These results imply a regulatory difference of the CYP27B1 hydroxylase to predispose to endocrine autoimmunity. © 2004 Society of the European Journal of Endocrinology.