All are features of adult polycystic kidney disease except
**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 progressive kidney damage and eventual loss of renal function. This condition is caused by mutations in the PKD1 or PKD2 genes, which encode for polycystin-1 and polycystin-2 proteins, respectively.
**Why the Correct Answer is Right**
The correct answer is **C.** Hematuria is a common feature of APKD, occurring due to the rupture of cysts into the urinary collecting system. This can lead to pain, infection, and eventually kidney failure. Hematuria is typically microscopic, but it can be gross in some cases. Other features of APKD include hypertension, kidney stones, and an increased risk of kidney cancer.
**Why Each Wrong Option is Incorrect**
**Option A:** Renal stones are indeed a feature of APKD, as the increased cystic fluid production can lead to the formation of stones within the urinary collecting system. However, this is not the correct answer as it is a feature, not an exception.
**Option B:** Hypertension is a common complication of APKD, resulting from the increased cystic fluid production and subsequent renal damage. This is not the correct answer as it is a feature, not an exception.
**Option C:** Hematuria is a feature of APKD, occurring due to the rupture of cysts into the urinary collecting system. This is the correct answer as it is an exception, not a feature of APKD.
**Clinical Pearl / High-Yield Fact**
It's essential to note that APKD can also lead to cardiovascular complications, including mitral valve prolapse and aortic root dilatation, due to the systemic effects of the polycystin proteins.
**Correct Answer: C. Hematuria is not a characteristic of Adult Polycystic Kidney Disease.**