Rett syndrome is a neurodevelopmental disorder that most commonly affects which group?

Rett syndrome is a neurodevelopmental disorder that most commonly affects which group?

• A. Boys
• B. Girls
• C. Elderly
• D. Athletes

Answer: (B)

Rett syndrome is an X-linked dominant neurodevelopmental disorder caused by mutations in the MECP2 gene. Because males with this mutation typically have more severe, often lethal outcomes in early life, the condition is far more commonly observed in females. Girls have two X chromosomes, and random X-inactivation leads to a mosaic of cells expressing the normal MECP2 gene, allowing survival and the characteristic developmental regression. In contrast, the other groups—elderly individuals or athletes—are not tied to this genetic pattern, so Rett syndrome most commonly affects girls.

Rett syndrome is an X-linked dominant neurodevelopmental disorder caused by mutations in the MECP2 gene. Because males with this mutation typically have more severe, often lethal outcomes in early life, the condition is far more commonly observed in females. Girls have two X chromosomes, and random X-inactivation leads to a mosaic of cells expressing the normal MECP2 gene, allowing survival and the characteristic developmental regression. In contrast, the other groups—elderly individuals or athletes—are not tied to this genetic pattern, so Rett syndrome most commonly affects girls.