Name an autoimmune muscular disorder.

Explanation

**Step-by-Step Text Solution:**

1. **Understanding Autoimmune Disorders**: Autoimmune disorders are conditions where the immune system mistakenly attacks the body's own healthy cells. This can lead to various health issues, including muscular disorders.

2. **Identifying an Autoimmune Muscular Disorder**: One well-known autoimmune muscular disorder is **Myasthenia Gravis**.

3. **Description of Myasthenia Gravis**: Myasthenia Gravis is characterized by weakness and rapid fatigue of the voluntary muscles. These are the muscles that are under conscious control, meaning they are used for movements that we think about, such as lifting an arm or smiling.

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