Vitamin D binding protein alleles and susceptibility for type 1 diabetes in Germans

Vitamin D has been shown to modulate the immune system thereby preventing t he development of diabetes in NOD mice. Since the vitamin D binding protein (DBP) is the main transporter for vitamin D and DBP has immunomodulatory p roperties itself, we investigated three polymorphic sites within the DBP ge ne as candidates for type 1 diabetes susceptibility for the first time. 152 Caucasian families with at least one affected offspring were genotyped for intron 8 [(TAAA)(n) repeat] and exon 11 (HaeIII, StyI) polymorphisms. T ransmission disequilibrium testing was used to detect preferential transmis sion to affected offspring. We found no significant transmission disequilib rium for DBP alleles, The strongest deviation from expected values was obse rved for the "10" allele (relative risk = 0.57, transmitted 13 of 36 times (corrected p = 0.249)), Although we cannot exclude an association of the studied DBP alleles with t ype I diabetes at present, these data do not suggest their contribution to this disease in Germans.