**Core Concept**
Glycogen storage diseases (GSDs) are a group of metabolic disorders caused by enzyme deficiencies that affect glycogen synthesis, breakdown, or both. These diseases lead to the accumulation of glycogen in various organs, including the liver and muscles. Von Gierke's disease is a specific type of GSD characterized by a deficiency of glucose-6-phosphatase, an enzyme crucial for glucose production from glycogen.

**Why the Correct Answer is Right**
Von Gierke's disease, also known as GSD type I, is caused by a deficiency of glucose-6-phosphatase, which is necessary for the final step of glycogenolysis and gluconeogenesis. In this disease, glycogen accumulates in the liver due to the inability to convert glucose-6-phosphate into glucose, which is then released into the bloodstream. This leads to hypoglycemia, lactic acidemia, and an increased risk of liver enlargement and failure.

**Why Each Wrong Option is Incorrect**
**Option A:** Fabry's disease is a lysosomal storage disorder caused by a deficiency of alpha-Gal A enzyme, leading to the accumulation of globotriaosylceramide in various organs, including the skin, kidneys, and heart. It is not classified as a glycogen storage disease.

**Option B:** Fragile syndrome, also known as Fragile X syndrome, is a genetic disorder caused by an expansion of the CGG repeat in the FMR1 gene, leading to the silencing of the gene and the absence of the fragile X mental retardation protein. It is not related to glycogen metabolism.

**Option D:** Krabbe's disease, also known as globoid cell leukodystrophy, is a lysosomal storage disorder caused by a deficiency of galactocerebroside beta-galactosidase, leading to the accumulation of galactosylceramide in the brain and nervous system. It is not classified as a glycogen storage disease.

**Clinical Pearl / High-Yield Fact**
To remember the types of glycogen storage diseases, use the mnemonic "GSDs: Glucose-6-phosphatase Deficiency (Von Gierke's), Glycogen Branching Enzyme Deficiency (Cori's), and others (e.g., McArdle's, Hers', Tarui's)". This will help you associate the correct enzymes with the respective diseases.

**✓ Correct Answer: C. Von Gierke’s disease**