Allelic loss on chromosome 11 is uncommon in parathyroid glands of patients with hypercalcaemic secondary hyperparathyroidism.

OBJECTIVE

To test the hypothesis that progression of secondary hyperparathyroidism from normocalcaemia to hypercalcaemia occurs because of development of monoclonal parathyroid tumours after the inactivation of a tumour suppressor gene on chromosome 11q13.

DESIGN

Experimental study.

SETTING

University hospital, Sweden.

SUBJECTS: 13 Patients with secondary hypercalcaemic hyperparathyroidism.

INTERVENTIONS: 48 Parathyroid glands were removed, 39 of which were analysed using Southern blot hybridisation and polymerase chain reaction.

MAIN OUTCOME MEASURES: Loss of heterozygosity on several loci on chromosome 11, including 11q13, which carries the presumed gene for multiple endocrine neoplasia type 1 (MEN1).

RESULTS

Monosomy for chromosome 11 was found in one tumour.

CONCLUSIONS

It seems unlikely that the MEN1 gene is of importance in the progression of secondary hyperparathyroidism.