Family Nurse Practitioner Exam

Which gender is often more severely affected by Fragile X disorder?

1. Males

2. Females

3. Both genders equally

4. Children under 10

The correct answer is: Males

Fragile X syndrome is a genetic disorder that results from a mutation in the FMR1 gene on the X chromosome. Males are generally more severely affected by Fragile X syndrome compared to females due to the fact that males have only one X chromosome (XY), while females have two (XX). If a male inherits the mutated X chromosome, he does not have a second X chromosome that could potentially mitigate the effects of the mutation. In contrast, females who inherit the mutated gene can still have a normal functioning X chromosome that may lessen the severity of the symptoms. Consequently, females may exhibit milder cognitive impairment and behavioral issues compared to males. This difference in phenotypic expression between genders is a key characteristic of X-linked disorders, making males more likely to exhibit the more severe features of Fragile X syndrome.