What is an example of an x-linked abnormality?

An example of an x-linked abnormality is color blindness. This condition is primarily associated with mutations in genes located on the X chromosome, specifically those affecting photopigments in the retina that are responsible for color vision. Since males have only one X chromosome, they are more likely to express color blindness when they inherit the mutated gene from their mother. Females, having two X chromosomes, may be carriers of the gene but are less likely to exhibit symptoms unless both X chromosomes carry the mutation.

Other conditions in the choices provided are caused by different types of genetic mutations. Sickle cell anemia and Tay-Sachs disease are autosomal recessive disorders, meaning that two copies of the mutated gene (one from each parent) are necessary for an individual to express the condition. Fragile X syndrome, while a genetic condition, is primarily caused by a mutation in the FMR1 gene on the X chromosome but it is not typically classified simply as an x-linked condition when considering the broader category of X-linked abnormalities. Color blindness is distinctly classified under X-linked conditions, making it the most accurate example in this context.