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

Myasthenia gravis is a chronic autoimmune disorder that specifically attacks the neuromuscular junction.

In this disease, the immune system produces antibodies that bind to and block the acetylcholine receptors on the post‑synaptic muscle membrane. Because acetylcholine cannot effectively stimulate the muscle fiber, the transmission of the nerve impulse is impaired.

The hallmark clinical features resulting from this impaired transmission are:

• Fatigue and rapid weakening of skeletal muscles during repeated use.
• Marked improvement of strength after a period of rest.
• In severe cases, paralysis of the affected muscles.

These symptoms match the description in the question: “fatigue, weakening and paralysis of skeletal muscle.”

Why the other options are incorrect:

• Gout is an inflammatory arthritis caused by uric‑acid crystal deposition in joints, leading to sudden, painful swelling—nothing to do with neuromuscular transmission.
• Arthritis refers broadly to joint inflammation, again unrelated to the neuromuscular junction or muscle fatigue.
• Muscular dystrophy comprises a group of genetic disorders that cause progressive muscle degeneration, not an autoimmune attack on acetylcholine receptors.

Therefore, the condition described in the question is Myasthenia gravis.