A female carries an autosomal recessive mitochondrial disorder. Which of the following systems are most likel… - INI-CET EXAM -2025

INI-CET EXAM -2025

Pathology & Genetics

Hard

Appeared in: INI-CET EXAM -2025

Explanation

Mitochondria are responsible for cellular energy (ATP) production. Disorders affecting them impact tissues with the highest energy requirements most severely.
The nervous system (neurogenic) and skeletal muscles are two of the most metabolically active tissues in the body, making them highly vulnerable to mitochondrial dysfunction.
The combination of muscle disease (myopathy) and neurological disease (encephalopathy) is a classic presentation for many mitochondrial disorders.
While the heart is also frequently affected, the pairing of skeletal and neurogenic systems represents a very common and characteristic pattern of mitochondrial disease.

Option A: The immune system is not considered a primary target of mitochondrial disorders in the same way as high-energy-demand tissues like muscle and brain. While skeletal muscle is commonly affected, the immune system is a less likely primary system to be involved.
Option B: This is a strong distractor because both the heart (cardiac) and skeletal muscles have high energy needs and are frequently affected. However, many classic mitochondrial syndromes are defined by the combination of neurological and muscular symptoms (encephalomyopathy), making the neurogenic component a key feature.
Option D: Similar to option A, this choice incorrectly pairs a less commonly affected system (immune) with a commonly affected one (cardiac). The primary impact is on tissues with the highest ATP consumption.

Visual 1: Diagram: Illustration of a cell showing the mitochondria and its role as the 'powerhouse' generating ATP.
Visual 2: Infographic: Chart listing body systems ranked by energy consumption, highlighting the brain, heart, and skeletal muscles at the top.
Visual 3: Micrograph: Image of a 'ragged red fiber' from a muscle biopsy, a characteristic finding in mitochondrial myopathies, showing the abnormal accumulation of mitochondria.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology of Mitochondrial Disorders as background academic context rather than a clinical decision trigger.
Nurses caring for patients with mitochondrial disorders must be prepared for multi-system involvement. A key nursing role is comprehensive assessment, monitoring for neurological changes (e.g., seizures, altered mental status), muscle weakness, and cardiac abnormalities (e.g., arrhythmias).
Patient and family education is crucial. Nurses can explain that symptoms like fatigue and exercise intolerance are due to the body's inability to produce enough energy, helping families understand the disease's nature.
What if? If the patient presented with only progressive external ophthalmoplegia (paralysis of eye muscles) and ptosis (drooping eyelids), the condition might be classified as Chronic Progressive External Ophthalmoplegia (CPEO), a specific type of mitochondrial myopathy where the eye muscles are predominantly affected.

How to Approach the Question

First, identify the core concept of the question: 'mitochondrial disorder'. Recall or deduce the primary function of mitochondria, which is energy (ATP) production.
Connect the function to the pathology. If energy production is faulty, which parts of the body would suffer most? The answer is tissues with the highest energy demand.
List the body's high-energy-demand systems: brain/nerves (neurogenic), skeletal muscle, and heart (cardiac).
Evaluate the given options by checking which pair consists of these high-demand systems.
Options A and D include the 'immune' system, which is not a primary high-energy-demand system in this context. Eliminate them.
Compare the remaining options: 'Cardiac and skeletal' vs. 'Skeletal and neurogenic'. Both are plausible as all three systems are heavily affected. Recall that the combination of brain and muscle involvement (encephalomyopathy) is a hallmark of many mitochondrial syndromes, making 'Skeletal and neurogenic' a very strong and representative answer.

Concept Tested & Keywords

Concept Tested: Pathophysiology of Mitochondrial Disorders
Stem keywords: autosomal recessive, mitochondrial disorder, systems affected
Lead-in keywords: most likely
Clinical cues: Age/sex group narrows the expected diagnosis, intervention, or normal reference range.
Negative lead-in flag: false

QOE7uyhz5nRK5EdhsRMDYw