Chronic auto immune disorder affecting neuromuscular junction leading to fatigue, weakening and paralysis of skeletal muscle is called as:

Solution & Explanation

Answer: (A) Myasthenia gravis Solution: Myasthenia gravis is a chronic auto-immune disorder in which antibodies target the neuromuscular junction, causing fatigue, progressive weakening and paralysis of skeletal muscles. NCERT explains that in auto-immune disease the body, due to genetic and other reasons, attacks its own self-cells (with rheumatoid arthritis given as the textbook example); myasthenia gravis is the extension example fitting the neuromuscular-junction description. Why others are wrong: Gout (uric-acid deposition) and arthritis are joint disorders, and muscular dystrophy is a genetic degenerative muscle disease — none is an auto-immune disorder of the neuromuscular junction. NCERT Reference: NCERT Ch7, p.137, lines 31-34: "the body attacks self-cells. This results in damage to the body and is called auto-immune disease"