**Question:** An infant has hepatosplenomegaly, hypoglycemia, hyperlipidemia, acidosis and normally structured glycogen deposition in the liver. What is the diagnosis –

A. Wilson's Disease
B. Congenital Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency
C. Congenital Hyperinsulinism
D. Congenital Hypothyroidism

**Correct Answer:** C. Congenital Hyperinsulinism

**Core Concept:** Congenital Hyperinsulinism is a rare disorder characterized by abnormally high levels of insulin, leading to hypoglycemia (low blood sugar levels) in infants. Insulin is a hormone produced by the beta cells of the pancreas, which lowers blood glucose levels by facilitating glucose uptake into cells. In Hyperinsulinism, the excessive insulin secretion results in a constant fight against low blood sugar levels, leading to the symptoms mentioned in the question.

**Why the Correct Answer is Right:** This correct answer (C) is selected because the infant exhibits hypoglycemia (low blood sugar levels), hepatosplenomegaly (enlargement of liver and spleen), and hyperlipidemia (elevated blood lipids) which are consistent with Congenital Hyperinsulinism. Additionally, the normally structured glycogen deposition in the liver suggests that the issue is with insulin production or action rather than glycogen storage disorders like glycogen storage disease.

**Why Each Wrong Option is Incorrect:**

A. Wilson's Disease (D106): Wilson's Disease is a copper-storage disorder caused by mutations in the ATP7B gene, leading to abnormal copper accumulation in the liver and other organs. The symptoms include liver dysfunction, neurological complications, and no mention of hypoglycemia, hepatosplenomegaly, or hyperlipidemia.

B. Congenital Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency (D100): G6PD deficiency is a genetic disorder caused by the deficiency of G6PD enzyme, which results in red blood cell damage. It is characterized by hemolysis (red blood cell breakdown) and jaundice, but not hypoglycemia, hepatosplenomegaly, or hyperlipidemia.

C. Congenital Hyperinsulinism (Correct Answer): As explained above, this option is correct due to the presence of hypoglycemia, hepatosplenomegaly, and hyperlipidemia in the given case.

D. Congenital Hypothyroidism (D101): Hypothyroidism is characterized by low thyroid hormone levels and resulting symptoms like developmental delays, weight gain impairment, and cold intolerance. It does not present with hypoglycemia, hepatosplenomegaly, or hyperlipidemia.

**Clinical Pearl:** This MCQ is a good example of how a detailed understanding of the clinical presentation and laboratory findings can lead to the correct diagnosis of Congenital Hyperinsulinism. The presence of hypoglycemia, hepatosplenomegaly, and hyperlipidemia allows us