**Question:** Not true about polycystic kidney disease is:

A. Polycystic kidney disease is a rare disease affecting only a small number of people.
B. The disease is caused by mutations in the PKD1 gene.
C. All patients with polycystic kidney disease have cysts in both kidneys.
D. Treatment options are limited to symptomatic relief only.

**Correct Answer: **D. Treatment options are limited to symptomatic relief only.**

**Core Concept:** Polycystic kidney disease (PKD) is a genetic disorder characterized by the formation of multiple fluid-filled cysts in the kidneys, liver, and other organs. PKD can be classified into two main types: autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive polycystic kidney disease (ARPKD). Both types are caused by mutations in specific genes: PKD1 in ADPKD and PKD2 in ARPKD.

**Why the Correct Answer is Right:**

While polycystic kidney disease is indeed a genetic disorder, the correct answer states that treatment options are limited to symptomatic relief only. In reality, various therapeutic approaches have been explored to address the complications associated with PKD, even though they cannot reverse the cyst growth or kidney function decline. Some of these treatment options include:

1. **Pharmacological interventions:** Medications like angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) can help control blood pressure, a common and severe complication in PKD patients.
2. **Dialysis and transplantation:** As PKD often leads to end-stage renal disease, patients may require dialysis or kidney transplantation as a life-sustaining treatment.
3. **Management of fluid and electrolyte balance:** Maintaining a proper fluid and electrolyte balance is crucial for patients with PKD, as it helps prevent fluid overload and its associated complications.
4. **Management of abdominal pain:** Non-steroidal anti-inflammatory drugs (NSAIDs) can help manage pain in PKD patients, although they do not address the cyst growth or kidney function decline.
5. **Vascular access management:** PKD patients require special care for vascular access during hemodialysis due to the risk of arteriovenous fistula stenosis or thrombosis.

**Why Each Wrong Option is Incorrect:**

A. While PKD is indeed a rare disease, the statement that it affects only a small number of people is incorrect. PKD is a relatively common disorder, affecting approximately 1 in 1,000 to 1 in 10,000 individuals globally, depending on the type (ADPKD or ARPKD) and the specific genetic mutation.

B. The PKD is caused by mutations in either PKD1 or PKD2 genes, which encode polycystin 1 and polycystin 2 proteins, respectively. The statement that PKD is caused by mutations in PKD1 gene is incorrect. PKD1 mutations are associated with ADPKD, while PKD2 mutations are associated with ARPKD.

C. The statement that PKD patients require