MP NHM CHO-2024 (Shif…: \ \ \ \ \ \ gene mutation is connected to a condition causing high cholesterol and heart disease.

MP NHM CHO-2024 (Shift-1)

Pathology & Genetics

Easy

Appeared in: MP NHM CHO-2024 (Shift-1)

Explanation

The LDLR gene encodes the low-density lipoprotein (LDL) receptor, which is crucial for clearing LDL cholesterol from the bloodstream.
Mutations in the LDLR gene cause Familial Hypercholesterolemia (FH), an autosomal dominant disorder.
Impaired function of LDL receptors leads to a significant increase in circulating LDL cholesterol levels.
Elevated LDL cholesterol is a major risk factor for the development of premature atherosclerosis and coronary artery disease.

Option A: Mutations in the CETP (Cholesteryl Ester Transfer Protein) gene primarily influence the levels of HDL ('good') cholesterol, not LDL ('bad') cholesterol. While related to lipid metabolism, it's not the primary cause of the condition described.
Option C: The ADBR2 (Beta-2 Adrenergic Receptor) gene is primarily associated with respiratory conditions like asthma and the body's response to certain medications (bronchodilators). It is not directly involved in the primary regulation of cholesterol metabolism.
Option D: The PPARG gene is a key regulator of fat cell differentiation and glucose metabolism. Mutations are linked to insulin resistance, type 2 diabetes, and lipodystrophy, not the specific high-LDL cholesterol profile of Familial Hypercholesterolemia.

Visual 1: Diagram: The LDL receptor pathway. A visual showing a normal liver cell clearing LDL from the blood versus a cell with defective LDLRs, leading to LDL accumulation in the artery.
Visual 2: Flowchart: Cascade screening for Familial Hypercholesterolemia. This would illustrate the process of testing family members of a diagnosed individual to identify others at risk.
Visual 3: Image: Tendon xanthomas. A picture showing the characteristic cholesterol deposits on tendons (e.g., Achilles tendon or hand knuckles) seen in severe, untreated FH.

Clinical Relevance

Nursing practice connection: Knowing Genetic basis of hypercholesterolemia and cardiovascular disease helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Early identification and aggressive management of Familial Hypercholesterolemia are critical to prevent premature heart attacks and strokes, often decades earlier than in the general population.
Nurses play a vital role in patient education regarding diet, medication adherence, and the importance of family screening (cascade screening) due to the autosomal dominant inheritance pattern of FH.
What if? If a patient presented with extremely LOW LDL cholesterol levels, a nurse might consider the possibility of a loss-of-function mutation in the PCSK9 gene, which has a protective effect against heart disease and is the target of a major class of cholesterol-lowering drugs.

How to Approach the Question

First, identify the core concepts in the question: 'gene mutation,' 'high cholesterol,' and 'heart disease.' This points to a genetic disorder of lipid metabolism.
Recognize this as a factual recall question requiring knowledge of the major genes involved in cholesterol regulation.
Systematically evaluate each gene option. Think about the primary function of the protein each gene codes for.
Recall that the LDL receptor is the primary mechanism for clearing 'bad' cholesterol. The gene for this receptor is LDLR.
Connect the defective LDLR gene to the inability to clear cholesterol, leading to high blood levels and subsequent heart disease.
Eliminate the other options by recalling their primary roles: CETP (HDL), ADBR2 (asthma/receptors), and PPARG (diabetes/insulin resistance).

Concept Tested & Keywords

Concept Tested: Genetic basis of hypercholesterolemia and cardiovascular disease
Stem keywords: gene mutation, high cholesterol, heart disease
Lead-in keywords: connected to

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E6 Pathology-Textbook of PATHOLOGY 9th Edition Harsh Mohan Part 2 (215-514) p. 215-514