ESPE Abstracts

Key words: primary hyperparathyroidism, parathyroid gland, genetic study.

Background: Primary hyperparathyroidism (PHPT) is a rare disease with a prevalence up to 2-5:100,000. About 90-95% of cases are isolated adenomas, 5-10% cases are due to hereditary syndromes. Parathyroid carcinomas occur in less than 1%.

Aim: To study clinical features and genetic characteristics of patients with primary hyperparathyroidism.

Materials and Methods: 49 patients with primary hyperparathyroidism was examined. Laboratory, instrumental diagnostic tests and molecular – genetic analysis were provided for all patients.

Results: The median age at the time of the examination was 15.81 [13,1; 16.8] years with median PTH 148.1 [87.0; 532.9] ng/mL, total calcium 2.97 [2.73; 3.2] mmol/L, calcium ionized 1.37 [1.3; 1.49] mmol/L, phosphorus 1.05 [0.91; 1.26] mmol/L. Hypercalciuria was diagnosed in 21 of patients (43%). Topical diagnostics of parathyroid gland was performed by ultrasound investigation and scintigraphy with Tc-99m-technetril, ectopic location was revealed in 5 patients (3 patients - intrathyroidal, 2 patients – mediastinal). The genetic basis of the disease was established in 17 patients (34,7%): MEN1 - 11 (22%), CDC73 - 3 (6%), RET - 2 (4%), SLC9A3R1 - 1 (2%). Surgical treatment was performed in 37 patients. Results of the morphological study revealed 31 adenomas (83,8%), 2 atypical adenomas (5,4%), 3 hyperplasias (8%) and 2 carcinomas (5%) of parathyroid glands. MEN1 pathogenic variants were found in 12,9% cases (4 patients) among the 31 histologically confirmed adenomas.

Conclusion: Molecular genetic analysis is indicated for all patients with PHPT. Pathogenic variants were identified in 17 (34,7%) of cases. MEN1 defects are the most common in PHPT and associated with adenomas.