Osteopetrosis is also known as:
**Core Concept**
Osteopetrosis is a rare genetic disorder characterized by an increase in bone density due to a defect in osteoclast function, leading to impaired bone resorption and a tendency for bones to become brittle and prone to fractures.
**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of osteopetrosis, which involves a defect in the function of osteoclasts, the cells responsible for bone resorption. This leads to an accumulation of dense, unresorbed bone tissue, resulting in the characteristic features of the disease.
**Why Each Wrong Option is Incorrect**
**Option A:** Marfan syndrome is a genetic disorder affecting the body's connective tissue, characterized by long limbs, an elongated face, and other distinctive features, but it is not related to bone density.
**Option B:** Cushing's disease is a rare endocrine disorder caused by excess cortisol production, leading to weight gain, hypertension, and other symptoms, but it is not directly related to osteopetrosis.
**Option C:** Osteomalacia is a condition characterized by softening of the bones due to a deficiency in vitamin D or calcium, but it is distinct from osteopetrosis in terms of bone density and resorption.
**Clinical Pearl / High-Yield Fact**
Osteopetrosis is often associated with an increased risk of fractures, dental abscesses, and other complications due to the abnormal bone structure.
**Correct Answer:** C. Marble bone disease