A 55-year-old man presents with a combination of fasciculations, muscle atrophy, hyperreflexia, and spasticity. Histological examination of the motor neurons reveals ubiquitinated intracytoplasmic inclusions. What is the major protein component of these inclusions?
- A Alpha-synuclein
- B Tau
- C TDP-43 ✓
- D Beta-amyloid
Correct answer: C. TDP-43
Explanation
Amyotrophic lateral sclerosis is characterized by degeneration of both upper and lower motor neurons. The hallmark ubiquitinated inclusions in motor neurons and glial cells are composed of TDP-43 in the majority of sporadic cases. Alpha-synuclein forms Lewy bodies in Parkinson disease.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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