**Question:** All are true about Celiac disease except

A. Celiac disease is a rare condition
B. Celiac disease is caused by a genetic predisposition
C. Celiac disease is characterized by malabsorption
D. Celiac disease is not associated with an autoimmune response

**Core Concept:** Celiac disease is an autoimmune disorder triggered by the ingestion of gluten, a protein found in wheat, barley, and rye. In genetically susceptible individuals, exposure to gluten leads to an immune response causing damage to the small intestinal mucosa, leading to malabsorption and various clinical manifestations.

**Why the Correct Answer is Right:**
Option A ("Celiac disease is a rare condition") is incorrect because celiac disease is not actually uncommon, affecting approximately 1% of the population worldwide. While it can be underdiagnosed, it is not rare.

Option B ("Celiac disease is caused by a genetic predisposition") is correct, as the disease is associated with the presence of specific HLA haplotypes (HLA-DQ2 and HLA-DQ8) in the majority of cases. These HLA antigens predispose an individual to develop an immune response to gluten, leading to celiac disease.

Option C ("Celiac disease is characterized by malabsorption") is correct because the primary pathophysiology of celiac disease involves the destruction of the villi in the small intestine, leading to impaired nutrient absorption.

Option D ("Celiac disease is not associated with an autoimmune response") is incorrect as celiac disease is indeed an autoimmune disorder. In genetically susceptible individuals, exposure to gluten triggers an immune response against the small intestinal mucosa, leading to inflammation and villous atrophy.

**Why Each Wrong Option is Incorrect:**

Option A: Celiac disease is not rare. A genetic predisposition and autoimmune response are key aspects in its pathogenesis. Malabsorption is a result of the disease, not a cause.

Option B: While celiac disease is associated with a genetic predisposition, it is an autoimmune disorder, not caused by genetic predisposition alone. The immune response against gluten is the primary aspect of celiac disease pathogenesis.

Option C: Malabsorption is a consequence of celiac disease, not a cause. The primary pathophysiology involves the autoimmune response against the small intestinal mucosa by gluten exposure.

Option D: Celiac disease is an autoimmune disorder, with an immune response against the small intestinal mucosa due to genetic predisposition.

**Clinical Pearls:**

Celiac disease is a severe reaction to gluten in genetically susceptible individuals, causing damage to the small intestinal mucosa and leading to impaired nutrient absorption. This disease is a result of an autoimmune response against the small intestinal mucosa, not simply genetic predisposition. The primary pathogenesis involves the immune response against gluten in genetically susceptible individuals, leading to villous atrophy and malabsorption.