Endocrine Abstracts

A 72 years old lady was referred to endocrine clinic with raised serum calcium of 2.69 mmol/l and PTH of 99.6 ng/l (3.0–48.0 ng/l) detected during investigations for an abnormal skeletal survey. She was known to have osteoporosis from the age of 59 diagnosed on Dexa scan. Case notes revealed raised serum calcium of 2.52–2.60 mmol/l since year 2000. Her repeat serum calcium was 2.77 mmol/l with phosphate of 1.03 mmol/l and 25 hydroxy vitamin D of 36 nmol/l. She admitted to symptoms of fatigue and increased thirst. There was no history of dyspepsia or renal calculi. She did not have any jaw swellings.

Family history showed several members of her family affected by primary hyperparathyroidism.

A high resolution ultrasound scan of the neck localised an adenoma in right superior parathyroid gland. The patient underwent parathyroidectomy and a single adenoma weighing 476 mg was removed from right superior parathyroid gland.

Hyperparathyroidism – Jaw Tumour (HPT – JT) syndrome is an autosomal dominant condition characterised by parathyroid adenoma/carcinoma and multiple ossifying jaw fibromas. The latter is not a constant finding. HPT – JT syndrome can be caused by mutations in the HRPT2 gene. Mutation screening of HRPT2 gene was undertaken in view of family history of hyperparathyroidism, even though the patient did not have any jaw tumours. She was found to have a T>C point mutation at nucleotide c.188 in exon 2 of HRPT2 gene. This results in the replacement of the amino acid leucine with proline at codon 63. This is a missense mutation in a highly conserved region, not previously reported in the literature. We are currently investigating the other members of this family.