Menin expression was down-regulated in MEN1 samples, including nonsense mutation and deletion mutant. Investigation of small numbers of parathyroid tumours by X-chromosome inactivation analysis suggests that the majority of them are monoclonal lesions most likely caused by a somatic mutation. To determine the prevalence of MEN1 gene mutations in monoclonal parathyroid neoplasias we investigated 33 parathyroid tumours of patients with primary hyperparathyroidism for clonality and mutations in the MEN1 gene. X-chromosome inactivation analysis was used to assess the clonal status of the tumours, direct sequencing of the complete coding region was applied to identify mutations in the MEN1 gene. Somatic mutations in the MEN1 gene were identified in nine cases.
Acute hyperparathyroidism is a rare and dangerous condition.
It is supposed to result from transformation of a mild chronic form into an acute and stormy illness. The causes and the mechanism of such a transformation are usually unknown. A case of acute hyperparathyroidism is presented in which hemorrhage into a parathyroid adenoma was recognized and diagnosed as the immediate cause of the transformation from the mild long-standing form of the disease into the severe acute form. No DNA sequence divergence within the 5' region of the MEN1 gene, containing the putative MEN1 promoter, was detectable in HP adenomas. Clinical characteristics were not different in HP patients with or without MEN1 mutation.