The incidence of Liver cysts in childhood polycystic kidney disease is –
**Core Concept**
Childhood polycystic kidney disease (PKD) is an autosomal dominant genetic disorder characterized by the growth of numerous cysts in the kidneys, often leading to renal failure. Liver cysts are a common extrarenal manifestation of this condition.
**Why the Correct Answer is Right**
Liver cysts in childhood PKD are thought to result from the same genetic mutation that affects the kidneys, specifically the mutations in the PKD1 and PKD2 genes. These mutations disrupt the normal functioning of the primary cilia, leading to the abnormal growth of cysts in both the kidneys and liver. The incidence of liver cysts in childhood PKD is relatively high, and they often become more prominent with age.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because liver cysts are not typically a primary feature of childhood PKD, although they can occur.
* **Option B:** This option is incorrect because the incidence of liver cysts in childhood PKD is not rare, but rather relatively common.
* **Option C:** This option is incorrect because liver cysts in childhood PKD are not usually associated with a specific age threshold.
**Clinical Pearl / High-Yield Fact**
It's essential to note that the presence of liver cysts in childhood PKD may not always be associated with significant symptoms or complications, but regular monitoring and imaging studies are crucial to detect any potential issues early.
**Correct Answer: C. 70-80%.**