A child was found to have hypoglycemia, hepatomegaly and muscle weakness. On histopathological examination, there was accumulation of highly branched glycogen called limit dextrins. He is likely to be suffering from –
**Core Concept**
The question is testing the understanding of glycogen storage diseases, specifically the identification of a disorder characterized by the accumulation of limit dextrins, a type of highly branched glycogen. This condition is associated with a deficiency of a key enzyme involved in glycogen breakdown.
**Why the Correct Answer is Right**
The child's symptoms, including hypoglycemia, hepatomegaly, and muscle weakness, suggest a disorder of glycogen metabolism. The accumulation of limit dextrins indicates a deficiency of debranching enzyme, which is necessary for the breakdown of glycogen to glucose. Debranching enzyme (glycogen debranching enzyme or amylo-alpha-1,6-glucosidase) is responsible for removing alpha-1,6-glycosidic bonds in glycogen, allowing for further breakdown by phosphorylase. The absence of this enzyme leads to the accumulation of limit dextrins, which are highly branched glycogen molecules.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is likely incorrect because it does not specify a glycogen storage disease. Glycogen storage diseases are a group of disorders characterized by the accumulation of glycogen in various tissues.
* **Option B:** This option might be incorrect because it does not accurately describe the specific enzyme deficiency associated with the accumulation of limit dextrins. Other glycogen storage diseases involve different enzyme deficiencies, such as phosphorylase or branching enzyme deficiencies.
* **Option D:** This option is likely incorrect because it does not accurately describe the symptoms or histopathological findings associated with this condition.
**Clinical Pearl / High-Yield Fact**
The accumulation of limit dextrins is a characteristic feature of debranching enzyme deficiency, also known as Cori disease or Glycogen Storage Disease Type III. This condition is caused by mutations in the AGL gene, which encodes the debranching enzyme.
**Correct Answer:** C. Debranching enzyme deficiency or Glycogen Storage Disease Type III.