Renal tubular acidosis due to Wilson's disease presenting as metabolic bone disease.

Two sisters presented with lower limb deformity and difficulty in walking without support. Both had short stature; however, neurodevelopment and secondary sexual characters were normal. Abdominal examination revealed splenomegaly and ophthalmic examination showed presence of Kayser-Fleischer (K-F) rings. Diagnosis of Wilson's disease was confirmed with low serum copper and ceruloplasmin levels. Further investigations revealed urinary acidification defect with hypercalciuria pointing towards distal renal tubular acidosis. Both patients were started on copper chelation therapy and showed gradual radiographic improvement in osteopaenia.