Arrange the following diseases in order of the zones of their involvement while going from metaphysis to epiphysis a. Gigantism b. Rickets c. Gaucher’s disease d. Scurvy
**Core Concept**
Growth plate disorders, such as those seen in Rickets, Scurvy, and Gaucher's disease, involve different zones of the growth plate, leading to characteristic abnormalities in bone growth and development. The growth plate, or epiphyseal plate, is composed of several zones, including the resting zone, proliferation zone, hypertrophic zone, and calcification zone, each with distinct cellular and histological features.
**Why the Correct Answer is Right**
To answer this question, we need to consider the pathophysiology of each disease and its effect on the growth plate. Rickets, caused by vitamin D deficiency, leads to defective calcification of the cartilage matrix, resulting in the involvement of the calcification zone (zone of provisional calcification) and the hypertrophic zone. Scurvy, caused by vitamin C deficiency, affects the collagen synthesis in the growth plate, leading to the involvement of the resting zone and the proliferation zone. Gaucher's disease, a lysosomal storage disorder, affects the osteoclasts and leads to the involvement of the metaphyseal region, just below the growth plate.
**Why Each Wrong Option is Incorrect**
**Option A:** Gigantism is caused by excess growth hormone, leading to overgrowth of the epiphysis, but it does not specifically affect the zones of the growth plate.
**Option B:** Rickets is correct, as explained above.
**Option C:** Gaucher's disease is correct, as explained above.
**Option D:** Scurvy is correct, as explained above.
**Clinical Pearl / High-Yield Fact**
Remember the "RSCG" mnemonic to recall the order of involvement of the growth plate zones in these diseases: Rickets (calcification zone and hypertrophic zone), Scurvy (resting zone and proliferation zone), Gaucher's disease (metaphyseal region), and Gigantism (epiphysis).
**Correct Answer: B. Rickets**