x-linked recessive

When a recessive gene occurs on the X chromosome, males will exhibit symptoms of a condition because they only have one copy of the X chromosome. Females who have two copies of the X chromosome are considered carriers of the condition. With this type of inheritance, females have a 50% chance of being a carrier of the condition if their mother is a carrier or their father is affected with the condition. Males have a 50% chance of being affected by the condition if their mother is a carrier. There is no father-to-son transmission of X-linked recessive inheritance.