Endocrine Abstracts

Introduction: 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.

Case report: We report the first Romanian family with HPT-JT and genetic screening of CDC73 gene. Three of the six screened family members included in this study had biochemical evidence of HPT and surgically proven parathyroid tumours. The index case (female, 35 yrs; Ca=13.9 mg/dl; PTH=327 pg/ml) had a parathyroid carcinoma and had been previously operated for OF of the jaw and uterine fibroid. At the time of screening she was asymptomatic 5 yr after parathyroid surgery.There were no renal lesions and jaw tumors in other family members. Two of the three afected members had parathyroid carcinomas (the index case and one of her brothers, 44 yrs, persistent HPT after many surgeries Ca=11.3 mg/dl; PTH=193.7 pg/ml) and one had two parathyroid adenomas (the brother’s son, 24 yrs, Ca=12.2 mg/dl; PTH=176 pg/ml). The genetic screening of CDC73 gene (PCR amplification and direct Sanger sequencing on genomic DNA extracted from peripheral blood leukocytes) revealed that 4 of 6 patients showed a new heterozygous germline deletion of one nucleotide: c.128-IVS1+1 delG. The parents were alive and asymptomatic, the father been the carrier of the mutation; the index case’ s daughter was negative for the mutation.

Conclusion: We identified a new germline mutation in a Romanian family of HPT-JT and confirmed the incomplete penetrance and the variable expression of the mutation.