Why Do Kids Get Hemophilia?
Hemophilia almost always affects boys. Why? Because the disease is an X-linked genetic disorder, passed from mother to son. Boys get an X chromosome (say: kro-muh-soam) from their mother and a Y chromosome from their father. If the mother carries the gene for hemophilia on one of her X chromosomes (girls have two X chromosomes), each of her sons will have a 50% chance of having hemophilia. A mother who is a carrier also has a 50% chance of giving the faulty X chromosome to her daughter. That does not give the daughter the hemophilia disease, but it does result in the daughter becoming a hemophilia carrier. So it’s possible one of her sons someday could have the disease.
