Endocrine Abstracts

Osteopetrosis and O.I. are both bone metabolic disorders with opposite features in terms of the metabolic turnover: while osteopetrozis has a low turnover and increased BMD due to the failure of osteoclasts to resorb bone, O.I. is well known as a high turnover disease with low BMD caused bt mutations in the COL1A1 and col COL1A2 genes that encode type 1 procollagen; yet, both condition, in spite of different mechanism, end up with increased ftracure prevalence. We report the case of a 46 year old women who presented for clinical and biological evaluation with a prior diagnisis of osteopetrosis. The anamnesis revealed that the diagnosis of osteopetrozis was set when the patient was 2 year old based on radiologycal features and multiple nontraumatic fractures suffered in childwhood; last fracture she recalls was at 20 year old and. Also she claims a familial history of osteogenesis imperfecta (maternal grandfather). The clinical examination revealed: Hight-125 cm; Weight-50 kg; BMI-32 kg/sm; blue sclerae, left leg orthosis, with unequal inferior limbs accompanied by difuze joint pain. Lab tests highlighted mild hypercholesterolemia, 25OHVitD insufficiency, low beta-crosslaps level, normal PTH, normal TSH and fT4. Near normal BMD. Dorsal and lombar spine X-ray:rarefaction of trabecular bone structure, suggesting a medium grade of demineralization.

Our O.I. final diagnosis proved to be quite difficult, taking into account the prior one of osteopetrosis, the history of pubertal fractures, familial history of O.I., growth impairment, lack of decreased BMD and increased bone turnover, mild VitD insufficiency. However, the importance of establishing the diagnosis, in our case, consists in choosing the optimal treatment; bisphosfonates are used in O.I. but not indicated in osteopetrosis. Our approach was to treat her with activ vit.D products since her actual fracture risk was not cinsidered increased.