October - December 2016, Volume 12, Issue 4

Grigorie D, Constantini A, Sucaliuc A

Suspected Non-LRP5 Mutation Associated with High Bone Mass Unaltered by Concurrent Symptomatic Primary Hyperparathyroidism of Long Duration

Acta Endo (Buc) 2016, 12 (4): 461-464
doi: 10.4183/aeb.2016.461

Background. Unexplained high bone mass (HBM) (Bone Mineral Density-BMD Z-score at the lumbar spine or hip of ≥+3.2 SD, or a combined spine and hip Z score ≥4 SD) after routine bone densitometry occurs with a prevalence of approximately 2 out of 1.000 and is currently believed to be a mild form of skeletal dysplasia (1). Results. We present the case of a patient with unexplained HBM (Z-scores at L3, L1-L4, total hip and radius total were +3, +2.7, +2 and +1.8, respectively) and concurrent symptomatic primay hyperparathyroidism (total serum calcium 11.9 mg/dL, serum Parathyroid Hormone - PTH 189.3 pg/mL) of long duration. There were no significant BMD changes at any skeletal site after the surgical cure of hyperparathyroidism. Testing for LRP (low density lipoprotein receptor-related proteins) 5 gene mutations was negative. Conclusions. We presented an unusual case of the association of a HBM with primary hyperparathyroidism with resistance to the catabolic action of PTH. In spite of the negative result of LRP5 testing we do believe that a mutation of a gene involved in the Wnt pathway in bone is responsible.

Keywords: Primary hyperparathyroidism, High bone mass, LRP-5.

Correspondence: Daniel Grigorie MD, “C.I. Parhon” National Institute of Endocrinology, 34-36 Aviatorilor Blvd., Bucharest, 011856, Romania, E-mail: grigorie_d@yahoo.com