Biology, Genetics & Bone Healing MCQs

What is the most effective medical treatment to alleviate the severe bone pain and improve muscle weakness in patients with Progressive diaphyseal dysplasia (Camurati-Engelmann disease)?

A 35-year-old patient undergoes curettage of a pathologically confirmed Chondromyxoid fibroma of the proximal tibia. What is the standard management to minimize the risk of local recurrence while preserving joint function?

A 10-year-old child presents with a waddling gait, severe leg pain, and generalized muscle weakness. Radiographs demonstrate symmetrical cortical thickening and sclerosis of the diaphyseal regions of the bilateral femurs and tibiae, sparing the epiphyses.

Which of the following medical treatments has been shown to be most effective in alleviating the pain and improving motor function in this condition?

A 12-year-old girl with a history of recurrent ear infections and progressive hearing loss develops a waddling gait and aching pain in her legs. Radiographs demonstrate marked symmetric endosteal and periosteal thickening of the long bone diaphyses.

This condition is most commonly caused by a mutation in which of the following genes?

Which of the following is a key distinguishing histological feature between Chondromyxoid Fibroma (CMF) and Chondroblastoma?

A pediatric patient with suspected Mucopolysaccharidosis undergoes diagnostic testing. Which of the following confirms the definitive diagnosis and specific subtype of the MPS?

A patient with Progressive Diaphyseal Dysplasia (Camurati-Engelmann disease) presents with severe, debilitating pain in the lower extremities.

Which of the following pharmacological treatments is considered first-line and highly effective for reducing bone pain and improving gait in these patients?

A 35-year-old man presents with chronic, deep aching pain and limited range of motion 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 diagnosis and its associated genetic mutation?

A 30-year-old female with polyostotic fibrous dysplasia complains of severe, persistent bone pain in her lower extremities that is refractory to simple analgesics. Radiographs show stable lesions without impending fractures. Which of the following pharmacological therapies is considered the first-line treatment to alleviate bone pain in this patient?

A 6-year-old child is diagnosed with Ollier disease. The parents are concerned about future limb length discrepancies and deformities. The deformities in Ollier disease are primarily caused by which of the following mechanisms?

Fibrous dysplasia is characterized by a somatic activating mutation in the GNAS gene. This specific mutation directly results in the constitutive activation of which of the following intracellular signaling pathways?

An 18-month-old presents with failure to thrive, recurrent infections, and hepatosplenomegaly. Radiographs reveal generalized increased bone density with a 'bone-within-bone' appearance. Which of the following is the only definitive curative treatment for the severe infantile form of this disease?

A newborn exhibits a prominently wide anterior fontanelle, midface hypoplasia, and an ability to bring the shoulders together across the midline. Radiographs reveal absent clavicles and delayed ossification of the pubic symphysis. This condition is caused by a defect in a transcription factor crucial for the differentiation of which cell type?

A 3-year-old child presents with bowing of the legs and a waddling gait. Radiographs show coxa vara and flaring of the metaphyses, primarily in the lower extremities. Laboratory tests reveal normal serum calcium, phosphorus, alkaline phosphatase, and vitamin D levels. Which of the following is the most likely diagnosis?

A 14-year-old girl with a history of recurrent fractures is evaluated for progressive restriction of forearm pronation and supination. Radiographs reveal calcification of the interosseous membrane and a history of hyperplastic callus formation following a previous femur fracture. She lacks blue sclerae or dentinogenesis imperfecta. A mutation in which gene is responsible for her specific phenotype?

A 10-year-old boy is evaluated for short stature and an unusual ability to approximate his shoulders anteriorly to the midline. Radiographs reveal a wide symphysis pubis, delayed cranial suture closure, and bilateral coxa vara. This condition is primarily caused by a defect in which of the following?

A 15-year-old boy sustains a transverse subtrochanteric femur fracture from a low-energy mechanism. Radiographs demonstrate generalized osteosclerosis, a "bone-within-bone" appearance in the spine, and an absent medullary canal in the long bones. A defect in which of the following cellular mechanisms is most likely responsible?

A 2-year-old girl with blue sclerae, dentinogenesis imperfecta, and multiple prior fragility fractures is started on intravenous pamidronate. Which of the following best describes the primary mechanism of action of this pharmacological treatment?