Question

Von Gierke's disease is a glycogen storage disease that occurs due to

• A. Deficiency of glucose-6-phosphatase
• B. Absence of debranching enzyme
• C. Absence of branching enzyme
• D. Absence of muscle phosphorylase

Hint:

Glycogen Storage Disease Types:
Type I (Von Gierke) $\rightarrow$ Glucose-6-Phosphatase.
Type II (Pompe) $\rightarrow$ Lysosomal acid maltase.
Type III (Cori) $\rightarrow$ Debranching enzyme.
Type V (McArdle) $\rightarrow$ Muscle Phosphorylase.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Glycogen Storage Diseases (GSDs) are inherited metabolic disorders caused by specific genetic enzyme deficiencies in glycogenolysis or gluconeogenesis.
Key Formula or Approach:
\[ \text{Glucose-6-Phosphate} + \text{H}_2\text{O} \xrightarrow{\text{Glucose-6-Phosphatase (Deficient in Type I GSD)}} \text{Free D-Glucose} + \text{P}_i \]

Step 2: Detailed Explanation:
Classification of Glycogen Storage Diseases (GSDs):
1. Type I GSD (Von Gierke's Disease): Deficiency of liver Glucose-6-Phosphatase (Type Ia) or translocase (Type Ib), preventing the final step of hepatic glycogenolysis and gluconeogenesis, causing severe fasting hypoglycemia, hepatomegaly, lactic acidosis, and hyperuricemia.
2. Type II (Pompe's): Lysosomal $\alpha$-1,4-glucosidase deficiency.
3. Type III (Cori's): Debranching enzyme deficiency.
4. Type IV (Andersen's): Branching enzyme deficiency.
5. Type V (McArdle's): Muscle glycogen phosphorylase deficiency.

Step 3: Final Answer:
Hence, Von Gierke's disease occurs due to Deficiency of glucose-6-phosphatase, matching option (A).