The NciI polymorphism in the cyclin D1 gene and sporadic primary hyperparathyroidism

Objectives. The cell cycle regulator cyclin D1 plays an important role in p arathyroid tumourigenesis. The NciI polymorphism in exon 4 has recently bee n associated with early onset of hereditary nonpolyposis colorectal cancer and is a prognostic indicator of nonsmall cell lung cancer and squamous cel l carcinomas. Furthermore, a limited study of 28 primary hyperparathyroidis m (pHPT) patients displayed a tendency of NciI influence on HPT development . We hypothesized that the NciI polymorphism may relate to a risk of develo ping pHPT. Design, setting and subjects. We genotyped 182 patients with sporadic pHPT and matched controls for the cyclin D1 polymorphism. A total of 88 pHPT pat ients and controls were recruited via a health-screening. Results. The frequency distribution of the NciI genotypes NN, Ni, and ii we re in pHPT patients and controls 22, 44 and 34%, and 26, 49 and 25%, respec tively. The calculated allele frequencies were A = 0.56: G = 0.44 in cases and A = 0.49; G = 0.51 in controls. The frequency distributions did not dif fer comparing cases and controls when subgrouped after age and menopausal s tatus. The NciI genotypes were not significantly associated with age of the individuals, serum (s)-calcium, s-parathyroid hormone (PTH), bone mineral density (BMD) or parathyroid tumour weight in any of the groups of pHPT pat ients or controls. Conclusions. No significant differences in distribution of the genotypes co uld be detected between the groups, suggesting that the polymorphism has mi nor or no pathogenic importance in the development of pHPT. Our results sug gest that determination of the NciI polymorphism in the cyclin D1 gene is n ot a clinically useful tool for prediction of pHPT.