HIGH RISK OF PARATHYROID CARCINOMA AND GENETIC SCREENING IN THE FIRST DIAGNOSED ROMANIAN FAMILY WITH HYPERPARATHYROIDISM-JAW TUMOR SYNDROME AND A GERMLINE MUTATION OF THE CDC73 GENE.

Context: Hyperparathyroidism-jaw tumour (HPT-JT) syndrome is a rare autosomal dominant cause of familial hyperparathyroidism associated with ossifying fibromas (OF) of the maxillofacial bones and increased risk of parathyroid carcinoma, caused by inactivating germline mutation of the cell division cycle 73 (CDC73) gene.

Objective: To report the first Romanian family with HPT-JT and genetic screening of CDC73 gene.

Subjects And Methods: Mutational analysis of the CDC73 gene and genetic screening of the family of a proband with HPT-JT. Histological diagnosis of parathyroid tumors (WHO criteria) and immunohistochemistry (parafibromin) were performed.

Results: Three of the six screened family members had evidence of PHPT and surgically proven parathyroid tumours. Two of the three affected members had parathyroid carcinomas and one had two parathyroid adenomas. Genetic screening of CDC73 gene revealed that 4 of 6 patients showed a heterozygous germline deletion of one nucleotide: c.128-IVS1+1 delG. All the three affected patients, resulted to be carriers of the CDC73 mutation, but each one bearing a different CDC73 polymorphism.

Conclusions: We identified a new CDC73 germline mutation in a Romanian family of HPT-JT. Analysis of clinical phenotypes in the four mutated individuals confirmed the incomplete penetrance and the variable clinical expression of the disease.