**Core Concept**
Rett's syndrome is a rare genetic disorder that affects brain development, leading to severe mental and physical disability. It is characterized by **regression of early developmental milestones**, particularly in areas of language and motor skills. The disorder is usually caused by a mutation in the **MECP2 gene**.

**Why the Correct Answer is Right**
Since the correct answer is not provided, let's discuss the general characteristics of Rett's syndrome. It typically presents in infancy, with **deceleration of head growth** and **loss of hand skills**. Affected individuals often exhibit **stereotypic hand movements**, such as hand wringing or clapping. The disorder is usually associated with **seizures**, **apraxia**, and **dysautonomia**.

**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific details of option A, we cannot determine why it is incorrect.
**Option B:** Similarly, without the details of option B, its incorrectness cannot be explained.
**Option C:** The same applies to option C.
**Option D:** And option D.

**Clinical Pearl / High-Yield Fact**
A key point to remember about Rett's syndrome is that it primarily affects **females**, as the **MECP2 gene** is located on the X chromosome. Males with the mutation typically do not survive infancy.

**Correct Answer:**