Review Question - QID 213709

A 72-year-old woman presents to the emergency department after she broke her wrist during a fall from standing height. On presentation, she says that she has gained a lot of weight since her husband died 6 months ago because she is eating junk food. She also describes experiencing pain in her bones but says she thinks it's because of the increased weight. Her past medical history is significant for scoliosis in childhood as well as a 30 pack-year history of smoking. Family history reveals 2 cousins who died in childhood due to fractures and frequent infections. Laboratory testing is obtained with the following results:

Calcium: 7.2 mg/dL
Phosphorus: 2.5 mg/dL
Alkaline phosphatase: 91 U/L

Which of the following is the most likely cause of this patient's symptoms?