[Chromosome abnormalities in hyperparathyroidism: utility of comparative genomic hybridization in the study of...

Genetic abnormalities responsible for primary (pHPT) and secondary hyperparathyroidism (sHPT) are not well described, especially those underlying the autonomous and refractory behaviour of glands from uremic patients with glandular hyperplasia and nodular growth. Comparative Genomic Hybridization (CGH) is a molecular cytogenetic technique based on a double-color in situ fluorescent analysis, allowing a global description of gains and losses of genomic material. It is a useful tool that localizes unstable genetic areas whose alteration could modify the expression of one or several genes related to the pathology in study. Results on primary hyperparathyroidism adenomas have shown a series of genetic changes correlating with areas where genes related to pHPT are located, such as MEN1 and cyclin D1. A large number of chromosomal aberrations in glands from patients with secondary hyperparathyroidism have also been found, and although some of them are common with those described for primary hyperparathyroidism, most of them are located in different areas or in a different proportion. These results confirm that although severe sHPT hyperplasias can evolve into neoplasias similar to pHPT adenomas, both parathyroid alterations must be considered, from a genetic point of view, as unrelated.