**Question:** Which is not a feature of Von Gierke disease?

A. Polyuria and polydipsia
B. Increased urine glucose levels
C. Increased urine ketones
D. Increased urine glucose levels

**Core Concept:** Von Gierke disease, also known as glycogen storage disease type II, is a rare autosomal recessive disorder characterized by the deficiency of glucose-6-phosphatase enzyme. This enzyme is crucial for the breakdown of glycogen in the liver, kidney, and muscle cells.

**Why the Correct Answer is Right:** Von Gierke disease primarily affects the liver, where the glucose-6-phosphatase enzyme deficiency leads to the accumulation of glycogen and subsequent defects in glucose and amino acid homeostasis. Despite this, the correct answer (D) does not mention glucose-6-phosphatase enzyme or glycogen accumulation, which are the primary features of Von Gierke disease.

**Why Each Wrong Option is Incorrect:**

A. Polyuria and polydipsia: These are features of diabetes insipidus, a condition characterized by excessive urine production due to the lack of arginine vasopressin (antidiuretic hormone) action on the kidney. In Von Gierke disease, polyuria and polydipsia are not present.

B. Increased urine glucose levels: While Von Gierke disease does cause increased urine glucose levels due to glycogen accumulation, option B is incorrect because it focuses on glucose levels, rather than the enzyme deficiency and glycogen accumulation that underlie the disease.

C. Increased urine ketones: Ketone bodies are elevated in the context of impaired glucose utilization, such as in diabetes mellitus. In Von Gierke disease, urine ketones are typically normal or slightly elevated, not increased.

**Clinical Pearl:** A thorough understanding of the underlying pathophysiology and clinical features of the disease is crucial to differentiate Von Gierke disease from other conditions such as diabetes mellitus. This understanding aids in appropriate diagnosis and management of the patient.