CLINICAL STUDY Frequency of the calcium-sensing receptor variant A986S in patients with primary hyperparathyroidism

Objective: Recent studies have shown an influence of the calcium-sensing receptor variant A986S on the serum calcium concentration, suggesting that this genetic variant could be a candidate for various bone and mineral disorders. The intention of this study was therefore to investigate the frequency of the described calcium-sensing receptor variants A986S, R990G and Q1011E in patients with primary hyperparathyroidism to test the hypothesis as to whether these variants represent risk factors for the development of primary hyperparathyroidism. Design: Fifty patients with primary hyperparathyroidism were included in the study. One hundred and two healthy blood donors served as controls. Methods: Detection of the genetic variants A986S, R990G and Q1011E was done by direct sequencing of exon 7 of the calcium-sensing receptor in leucocyte DNA. Results: The heterozygous variant A986S was found in 34 % (17 of 50) of the healthy age- and sex-matched controls and 40 % (20 of 50) of the patients with primary hyperparathyroidism. This difference was not statistically significant \u85P 0:68: However, in male patients the heterozygous variant A986S was found more frequently (67%, 6 of 9) than in male controls (20%, 2 of 10