Human stanniocalcin (STC): genomic structure, chromosomal localization, and the presence of CAG trinucleotide repeats

Stanniocalcin (STC) is a glycoprotein hormone that is secreted by the corpuscle of Stannius, an endocrine gland of bony fish. It prevents hypercalcemia via mechanisms including inhibition of calcium uptake across the gills. Mammalian homologues have recently been reported but their function is unknown. Here we report the genomic organization and the transcription start site of the human STC gene and the existence of a polymorphic CAG trinucleotide repeat complex within the 5' untranslated region (UTR) of the mRNA and a smaller [CAG]6 repeat in the 3' UTR. As CAG repeats are associated with various human diseases, we used dual-color fluorescence in situ hybridization to localize the STC gene near markers D8S131 and D8S339 on chromosome 8p11.2-p21. STC should be considered a candidate gene for hereditary diseases mapped to this region.