What is the inheritance pattern of Fragile X syndrome?

Fragile X syndrome is inherited in an X-linked dominant manner, which means that the gene associated with the condition is located on the X chromosome. This means that if a male inherits the mutated gene, he will express the condition, as he has only one X chromosome (paired with a Y chromosome). Females, who have two X chromosomes, are more likely to be carriers and may express the condition if they inherit one affected X chromosome.

In affected females, there is often a range of severity due to the presence of a second X chromosome. The application of X-linked dominant inheritance is significant in understanding how the condition can manifest differently in males and females, as males typically exhibit more severe symptoms because they do not have a second X chromosome that could mitigate the effects of the mutation.

The other choices are not correct because autosomal dominant and autosomal recessive inheritance patterns do not apply to this condition, and chromosomal deletion refers to a different kind of genetic anomaly that does not specifically describe how Fragile X syndrome is passed from parent to child. The key characteristic of Fragile X syndrome is indeed its association with the X chromosome, confirming its classification as X-linked dominant.