Biology, Genetics & Bone Healing MCQs

A 6-year-old boy has sustained multiple low-energy fractures. Examination shows blue sclerae and mild hearing loss. The primary underlying defect in this condition involves which of the following?

A 10-year-old girl exhibits hypermobility of her shoulders allowing them to meet in the midline. She also has delayed eruption of permanent teeth. What is the most likely genetic mutation responsible for her condition?

A 65-year-old man presents with increasing head size and dull, aching pain in his right thigh. Radiographs of the femur demonstrate a thickened cortex with a "blade of grass" lucency at the leading edge. What is the primary cellular defect in this condition?

A newborn presents with short-limbed dwarfism, "hitchhiker" thumbs, clubfeet, and "cauliflower" ears. Radiographs reveal severely shortened first metacarpals. What is the underlying genetic defect in this dysplasia?

A 62-year-old female with long-standing diabetes mellitus presents with a swollen, warm, and erythematous right foot. Radiographs show early fragmentation of the tarsometatarsal joints. The neurovascular theory of Charcot arthropathy pathogenesis suggests that this condition is primarily driven by which of the following mechanisms?

A medical student is instructed to perform a diabetic foot screening using a 5.07 Semmes-Weinstein monofilament. To ensure an accurate assessment of protective sensation, which of the following describes the correct technique for applying the monofilament?

Recent molecular research into the pathogenesis of acute Charcot neuroarthropathy suggests an imbalance in bone turnover. Which of the following best describes the underlying cytokine alteration contributing to excessive osteoclastogenesis in this condition?

A 12-year-old girl with delayed closure of cranial sutures, absent clavicles, and supernumerary teeth is being evaluated in the orthopedic clinic. Which of the following spinal anomalies is most commonly associated with her underlying genetic condition?

A 6-year-old boy with a history of multiple low-energy fractures, blue sclerae, and dentinogenesis imperfecta is started on intravenous pamidronate. What is the primary mechanism by which this medication increases bone mineral density in this patient?

A 10-year-old boy presents for evaluation of shoulder hypermobility. Examination reveals he can bring his shoulders together anteriorly in the midline. He also has a delayed eruption of permanent teeth. What transcription factor, essential for osteoblast differentiation, is defective in this condition?

A 6-year-old child with blue sclerae, dentinogenesis imperfecta, and multiple prior long bone fractures is scheduled for rodding of the femurs. Which of the following best describes the fundamental defect in this patient's condition?

A newborn presents with open cranial sutures, absent clavicles, and delayed eruption of primary teeth. What is the fundamental mechanism of this patient's skeletal dysplasia?

A 6-year-old child presents with frequent fractures, anemia, and cranial nerve palsies. Radiographs demonstrate uniformly dense bones with a "bone-within-bone" appearance. A defect in which cell type is primarily responsible for this disorder?

A patient presents with absent clavicles, delayed closure of cranial sutures, and supernumerary teeth. What gene mutation is associated with this disorder?

A 10-year-old child presents with a waddling gait and knee pain. Radiographs demonstrate delayed, irregular epiphyseal ossification centers in the large joints, but the spine is entirely normal. Mutations in which of the following genes are most commonly responsible for the autosomal dominant form of this condition?

A 15-year-old male is referred for delayed tooth eruption and unusual shoulder mobility, allowing him to approximate his shoulders anteriorly at the midline. The primary genetic defect (CBFA1/RUNX2) in this condition impairs which of the following biological processes?

A 35-year-old female presents with chronic, severe pain and stiffness in her right lower extremity. Radiographs show dense, irregular, eccentric hyperostosis along the cortex of the femur and tibia, resembling 'dripping candle wax'. What is the most likely diagnosis?

A 30-year-old patient with polyostotic fibrous dysplasia complains of severe, persistent bone pain in the lower extremities that limits daily activities. Surgical intervention is not currently indicated for structural reasons. Which of the following pharmacological therapies has the best evidence for reducing bone pain in this condition?

A 30-year-old male presents with severe, deep, aching pain and progressive joint contracture in his left lower extremity. Radiographs demonstrate dense, irregular, eccentric hyperostosis along the cortex of the femur and tibia, resembling 'dripping candle wax'. Which of the following is the most likely genetic mutation associated with this condition?

In a patient with Ollier disease, the characteristic skeletal lesions are primarily a result of which of the following pathophysiological processes?