Primary hyperparathyroidism and jaw tumor syndrome: a novel mutation of the HRPT2 gene.

OBJECTIVE

To discuss a case of hyperparathyroidism-jaw tumor syndrome (HPT-JT) and its clinical course, as well as describe a new mutation within HRPT2, the gene associated with HPT-JT.

METHODS

We describe the clinical course, laboratory data, and diagnostic imaging of a patient with HPT-JT, including the mutation analysis of the HRPT2 gene. A review of the related literature is also presented.

RESULTS

A 22-year-old man presented with progressive bone pain and weakness, and investigation revealed a serum calcium level of 17.6 mg/dL, a phosphorus concentration of 1.8 mg/dL, and an intact parathyroid hormone value of 2,808 pg/mL. X-ray examinations showed a fracture of the left hip and compression fractures of the lumbar spine. Computed tomography disclosed a mass in his mandible, clinically suggesting HPT-JT. Genetic analysis of the HRPT2 gene demonstrated a frameshift mutation resulting in a premature stop codon. The patient underwent parathyroidectomy, and 1 year later his fractures had healed and dual-energy x-ray absorptiometry showed substantial improvement in bone mineral density.

CONCLUSION

Previous reports have cited mutations of the gene HRPT2 leading to HPT-JT and its associated phenotypes. We report one such mutation, not reported previously, in a patient with HPT-JT. This case adds to the growing evidence that different mutations in the HRPT2 gene can lead to HPT-JT, although it remains unclear whether specific mutations are more strongly associated with a particular phenotype.