**Question:** Which is Not true regarding Hypertrophic pyloric stenosis -

A. Hypertrophic pyloric stenosis (HPS) is a condition affecting infants, characterized by the excessive thickening and narrowing of the pyloric muscle in the stomach.
B. The condition is primarily caused by an unknown genetic mutation.
C. Symptoms typically include vomiting, feeding difficulties, and weight loss in infants.
D. Treatment for HPS is usually surgical, involving the removal of the pyloric muscle.

**Correct Answer:**

**Option B: "Primarily caused by an unknown genetic mutation."**

Hypertrophic pyloric stenosis is primarily caused by a complex interplay of genetic and environmental factors. Although a genetic predisposition is recognized, the exact cause is still not fully understood. Genetic factors may contribute to the condition's development, but other factors, such as nutrient content in breast milk or cow's milk, have also been proposed. Consequently, claiming that it is primarily caused by an unknown genetic mutation is not entirely accurate.

**Why the Correct Answer is Right:**

Hypertrophic pyloric stenosis is a clinical condition characterized by the excessive proliferation and hypertrophy of the pyloric muscle, resulting in pyloric muscle thickening and narrowing. This condition is usually managed through a surgical intervention called pyloromyotomy, which involves making a small incision in the pyloric muscle to relieve the obstruction.

**Why Each Wrong Option is Incorrect:**

**Option A:** Although the pyloric muscle thickening is a defining feature of HPS, stating that it is a "condition affecting infants" is broadly true. However, the question asks for the statement that is NOT true, making this option incorrect as it does not specifically negate any crucial aspect of the condition.

**Option C:** While the symptoms of vomiting, feeding difficulties, and weight loss are common in infants with HPS, the question asks for the statement that is NOT true. Claiming that the condition primarily affects infants is a broader statement that may not specifically address the condition's key features.

**Option D:** The statement "Treatment for HPS is usually surgical, involving the removal of the pyloric muscle" is not true in the context of the question. Hypertrophic pyloric stenosis is primarily managed through a surgical procedure called pyloromyotomy. This surgical intervention is intended to relieve the obstruction caused by the hypertrophic pyloric muscle.

**Core Concept:**

Hypertrophic pyloric stenosis (HPS) is a digestive disorder seen in infants characterized by the excessive proliferation and hypertrophy of the pyloric muscle, leading to a narrowing of the pyloric muscle. This results in the symptoms of vomiting, feeding difficulties, and weight loss in infants.

**Why the Correct Answer is Right:**

The correct answer (Option D) highlights that the treatment for HPS typically involves a surgical procedure called pyloromyotomy. This procedure aims to relieve the obstruction caused by the hypertrophic pyloric muscle.

**Why Each Wrong Option is Incorrect:**

**Option