How do X-linked recessive alleles work?

There is one kind of muscular dystrophy, caused by an X linked recessive allele, that causes loss of muscle function and ultimately death by the age of about twenty. The disorder usually occurs in males. Can you explain why?

How do X-linked recessive alleles work?
Females are XX


Males are XY





it's recessive so for a female to have muscular dystrophy, it must be on both of her X chromosomes.. That's why for X-linked recessive disorders, females tend to be carriers more often then affected by the actualy disease.


For males it's impossible for them to be carriers so if they recieve an affected X chromosome, they're screwed. They have it no matter what.
Reply:Men are XY, and women are XX. X-linked recessive alleles are usually more prominent in men because they only need to get the recessive allele one time on their only x chromosome. For women to have a disease that is x-linked recessive, they must have the recessive allele on both of their X chromosomes.
Reply:because males have x and y and all he needs is the x to have the recessive trait...however, in females we have x and x sex chromosomes so we need it on both x's. using a punnett square this means that your mom must be a carrier and your dad must have the disease. i hope this helped