Which inheritance pattern is characterized by more frequent expression in males and can be carried by females?

Which inheritance pattern is characterized by more frequent expression in males and can be carried by females?

• A. X-Linked Dominant
• B. X-Linked Recessive
• C. Autosomal Recessive
• D. Mitochondrial Inheritance

Answer: (B)

X-linked recessive inheritance is the pattern at play. The gene responsible is on the X chromosome, and the trait requires two copies to show in females but only one copy to show in males. Because males have only one X, a single mutated allele on that X leads to expression of the trait, so males are affected more often. Females have two X chromosomes, so a normal copy can mask a mutated one, making them carriers who typically don’t show symptoms. These carrier females can pass the mutation to their children: a son who inherits the mutant X will be affected, while a daughter who inherits it becomes a carrier. If an affected father passes his mutated X to all daughters, they become carriers, illustrating how the pattern can be carried by females even though expression is more common in males.

X-linked recessive inheritance is the pattern at play. The gene responsible is on the X chromosome, and the trait requires two copies to show in females but only one copy to show in males. Because males have only one X, a single mutated allele on that X leads to expression of the trait, so males are affected more often. Females have two X chromosomes, so a normal copy can mask a mutated one, making them carriers who typically don’t show symptoms. These carrier females can pass the mutation to their children: a son who inherits the mutant X will be affected, while a daughter who inherits it becomes a carrier. If an affected father passes his mutated X to all daughters, they become carriers, illustrating how the pattern can be carried by females even though expression is more common in males.