Hypophosphataemic rickets/osteomalacia: a descriptive analysis.

BACKGROUND & OBJECTIVES Hypophosphataemic rickets/osteomalacia (HRO) is an uncommon metabolic bone disorder which affects all ages and either sex. It is characterized by low concentration of serum phosphate levels leading to impairment of mineralization of bone matrix with variable aetiology. We present clinical profile and treatment outcome of 17 patients of HRO. METHODS Seventeen consecutive patients (8 were < 18 yr of age, with median age of presentation being 27.5 yr) of HRO who came to the department of Endocrinology in a tertiary care hospital in north India from January 2000 to December 2006 were included in the present study. Their aetiology, clinical features, biochemical parameters, radiographic features, treatment and outcome were analyzed. RESULTS HRO was commoner in females (70.5%) with positive family history observed in 6 (35.3%) patients. Common presenting features were short stature (58.8%), backache (58.8%), bony deformities (58.8%), joint pain (52.9%), fractures (29.4%) and dental abnormalities (23.5%). Radiological abnormalities noted were generalized bony deformities (58.8%), fractures (29.4%), and pseudo fractures (17.6%). Mesenchymal tumours were localized in the pelvis in one patient and in the right jaw in another. The patients were treated with calcium (elemental calcium 1 g/d) and oral phosphate supplements (dose 30 - 50mg/kg/day in divided doses) along with active vitamin D supplements (dose 1 - 3 microg/day) and followed up for a mean of 2 yr. Two patients also received growth hormone (GH) therapy in the dose of 2U/day for 6 and 18 months respectively. Symptomatic well being was reported by all the patients and improvement was noted in the levels of phosphate (P<0.005) and alkaline phosphatase (P<0.05) after treatment. INTERPRETATION & CONCLUSIONS A diagnosis of HRO should be considered in all patients presenting with short stature, deformities or musculoskeletal pains along with low serum phosphate with normal iPTH and 25--hydroxy vitamin D.