Question

Friedreich's ataxia is usually NOT associated with

• A. CNS abnormalities
• B. Peripheral nerve involvement
• C. Cardiovascular abnormalities
• D. Acid-peptic disorders

Hint:

Think about which single organ system falls outside the classic neuro-cardiac-skeletal triad of this disease.

Answer 1

The Correct Option is D

Step 1: Understanding the Question:
The question asks which system is NOT typically involved in Friedreich's ataxia, an inherited neurodegenerative disorder. This tests knowledge of the multisystem nature of the disease beyond just the neurological picture.

Step 2: Key Concept or Approach:
Friedreich's ataxia is an autosomal recessive disorder caused by a GAA trinucleotide repeat expansion in the frataxin gene on chromosome 9, leading to mitochondrial iron accumulation and degeneration of the dorsal columns, spinocerebellar tracts, corticospinal tracts, and peripheral sensory neurons. Frataxin deficiency also affects cardiac muscle and pancreatic beta cells, producing a recognizable multisystem pattern: neurological, cardiac, skeletal, and endocrine involvement, but no primary gastrointestinal effect.

Step 3: Working Through the Options:
CNS abnormalities are core to the disease -- degeneration of the spinocerebellar tracts, dorsal columns, and corticospinal tracts produces the ataxia, loss of proprioception, and extensor plantar responses that define the condition. Peripheral nerve involvement is also expected, with loss of large sensory fibers causing absent deep tendon reflexes and impaired vibration/position sense. Cardiovascular abnormalities are a well-recognized and often life-limiting feature -- hypertrophic cardiomyopathy occurs in the majority of patients and is a leading cause of death. Acid-peptic disorders, however, have no established mechanistic link to frataxin deficiency; the gastrointestinal tract is not a target organ in this disease, unlike the heart, nervous system, skeleton (pes cavus, kyphoscoliosis), and pancreas (diabetes mellitus in a subset of patients).

Step 4: Conclusion:
The correct answer is acid-peptic disorders, since Friedreich's ataxia does not affect the gastrointestinal system while it consistently affects the central and peripheral nervous system and the heart.