Osteopetrosis, also known as marble bone disease, was first described by Albers-Schonberg in 1904. It is a rare group of heterogenous genetic disorders characterised by abnormal osteoclast activity and impaired bone resorption, which results in increased bone mass throughout the skeleton. Yet, despite seemingly better than normal bone density, it is associated with increased fractures and delayed healing.
We present two cases of autosomal dominant osteopetrosis (ADO), type 11. The first case is a 57-year-old-caucasian lady, who was referred for recurrent fragility fractures from the age of 12, despite robust bone density with T-scores of + 3.4 SD in her lumbar spine and +2.9 SD in the right femoral neck. The second case is a 36-year-old-Asian man, similarly referred for recurrent fragility fractures, which began at the age of 13. His bone density was significantly elevated with T-scores of +7.1 SD in his lumbar spine and +13.6 SD in the right femoral neck. Interestingly, his younger brother also had a history of fractures starting from a young age with similar bone density measurements.
These two cases illustrate the genetic, clinical and radiological features of osteopetrosis. Furthermore, while there is no specific treatment for ADO except symptomatic management, we explore the role of high dose calcitriol (1,25-dihydroxyvitamin D),a known potent stimulator of osteoclast precursor proliferation and differentiation.