Which one of the following statements is wrong regarding adult polycystic kidney disease ?
**Core Concept**
Adult polycystic kidney disease (APKD) is a genetic disorder characterized by the growth of numerous cysts filled with fluid in the kidneys, leading to kidney enlargement and eventual kidney failure. The condition is caused by mutations in the PKD1 or PKD2 genes, which encode for polycystin-1 and polycystin-2, proteins that play a crucial role in maintaining the structure and function of the renal tubules.
**Why the Correct Answer is Right**
The correct statement regarding APKD is that it is associated with an increased risk of developing intracranial aneurysms and cerebral hemorrhage. This is due to the presence of polycystin-1 and polycystin-2 in the vascular smooth muscle cells of the brain, which contribute to the pathogenesis of cerebral aneurysms. The risk of intracranial aneurysms is particularly high in individuals with APKD, and it is essential to screen for this complication in patients with a family history of APKD.
**Why Each Wrong Option is Incorrect**
**Option A:** APKD is characterized by the growth of cysts in the kidneys, but it can also affect other organs, including the liver, pancreas, and heart. However, the primary and most significant impact of APKD is on the kidneys.
**Option B:** APKD is inherited in an autosomal dominant pattern, meaning that a single copy of the mutated gene is sufficient to cause the condition. This is correct.
**Option C:** APKD is associated with an increased risk of developing hypertension, which can exacerbate kidney damage and accelerate the progression of the disease. This is correct.
**Clinical Pearl / High-Yield Fact**
It is essential for clinicians to recognize that APKD is a systemic disorder that affects multiple organs beyond the kidneys. Regular screening for extrarenal manifestations, such as intracranial aneurysms and cardiac abnormalities, is crucial in the management of APKD patients.
**Correct Answer:** C.