Which type of inheritance does Rett syndrome fall into?

• A. X-linked dominant
• B. X-linked recessive
• C. Autosomal dominant
• D. Autosomal recessive

Answer: (A)

Rett syndrome is classified as an X-linked dominant disorder. This classification means that the gene mutation responsible for the syndrome is located on the X chromosome, and the presence of a single copy of the mutated gene can lead to the development of the disorder, primarily affecting females.

In X-linked dominant conditions, only one mutated copy of the gene is required for an individual to manifest the disorder, which is why it primarily affects females, who have two X chromosomes. Males, having only one X chromosome, may experience more severe effects if they inherit the mutated gene.

The hallmark symptoms of Rett syndrome often appear after a period of normal development, typically between 6 to 18 months of age, leading to a regression of skills, particularly in communication and motor abilities. Understanding that Rett syndrome is X-linked dominant is essential for comprehending its inheritance patterns and the implications for family genetics.