X-linked hypophosphatemic rickets, also known as vitamin D-resistant rickets, is inherited by a dominant gene located on chromosome X. These children, who are normal at birth, develop genu varum, genu valgum, coxa vara and “X or O bain” deformities in the weight-bearing joints when they begin walking. A seven-year-old boy was diagnosed with hypophosphatemic rickets upon presentation due to a one-year history of difficulty in walking and running. The patient’s clinical and radiological findings responded dramatically to the treatment with calcitriol and Joulie’s solution (dibasic sodium phosphate). We report this patient together with a review of literature because of the rarity of the disease and because the clinical findings first appeared at a relatively older age.

Keywords: Hipofosfatemi, fosfatüri, rikets, hypophosphatemia, phosphaturia, rickets