What is her diagnosis?

A young female of 24 years, presents with bony pains and difficulty in walking for 2 years. Her plain radiographs show fractures of right shaft of tibia and fibula and diffuse osteopenia. Screw and plating was seen at right femur for which patient gives a past history of fracture due to trivial trauma 3 years back. Her biochemical parameters reveal serum Ca 13.4 mg/dL, serum phosphorus 1.4 mg/dL, serum creatinine 1.2 mg/dL. Hb is 11.0 g%. 25(OH)D value is 45 ng/dL and her PTH is 108 pg/mL. USG abdomen shows left renal calculus. BMD shows severe osteoporosis. Her past history reveals being treated for 6 months for pulmonary tuber- culosis 4 years back. Her mother expired from non-Hodgkin’s lymphoma 12 years back.

What is her diagnosis?