Which disorder is characterized by affecting only females and includes microcephaly and seizures?

Rett Syndrome is a neurodevelopmental disorder that primarily affects females, typically presenting between six months and two years of age. One of its most distinctive features is the loss of purposeful hand skills and the development of repetitive hand movements, often accompanied by cognitive impairment and difficulties with movement and coordination. The condition is often associated with microcephaly, which is a smaller-than-average head size, and seizures, which are commonly experienced by individuals with the disorder.

The unique sex-linked genetic mutation responsible for Rett Syndrome is found on the MECP2 gene located on the X chromosome. This genetic aspect is significant since it predominantly affects girls, as boys with the mutation often do not survive or exhibit more severe conditions due to having only one X chromosome, leading to lethality early in development.

This combination of characteristics—affecting only females, microcephaly, and seizures—strongly identifies Rett Syndrome as the correct answer.