The vitamin D receptor (VDR) start codon polymorphism in primary hyperparathyroidism and parathyroid VDR messenger ribonucleic acid levels

Vitamin D regulates parathyroid cell proliferation and secretion of PTH. In creased prevalence of the polymorphic vitamin D receptor (VDR) alleles b, a , and T has been reported in sporadic primary hyperparathyroidism (PHPT), s uggesting that these genetic variants may predispose to the disease. Recent ly, another polymorphism in the VDR gene was related to bone mineral densit y, and this VDR-FokI polymorphism causes different lengths of the VDR, impl ying possible functional consequences. The VDR-FokI polymorphism was studie d in 182 postmenopausal women with sporadic PHPT and in matched controls. N o significant differences in distribution of the VDR-FokI genotypes could b e detected between the groups, although there was a tendency toward overrep resentation of the F allele in the PHPT patients (P = 0.05). There were no significant associations with age, serum calcium, serum PTH, bone mineral d ensity, or parathyroid tumor weight. The VDR genotypes were unrelated to VD R and PTH messenger ribonucleic acid levels in the parathyroid adenomas of 42 PHPT patients. In 23 PHPT patients, the Ca2+-PTH set-points were determi ned in vivo and were unrelated to the VDR alleles. We suggest that the VDR- FokI polymorphism has at most a minor pathogenic importance in the. develop ment of PHPT.