are  males carriers of hemophilia
People who have severe hemophilia have spontaneous bleeding into the joints and muscles. Hemophilia occurs more commonly in males than in females. The two most common types of hemophilia are hemophilia A (also known as classic hemophilia) and hemophilia B (also known as Christmas disease). People who have hemophilia A have low levels of a blood clotting factor called factor eight (FVIII). Figure 5 shows the heredity pattern when a normal male has a child with a female carrier of hemophilia. If they have a son, he has a 50% chance of having hemophilia. This is determined by which X chromosome he inherits. If he inherits the mother's normal X chromosome, the boy will not have hemophilia. Carriers have one normal X chromosome and one abnormal X chromosome. The normal X chromosome produces a certain amount of factor VIII or IX clotting factor. This protects carriers from the most severe form of hemophilia in which the level of clotting factor is less than 1%. A woman may or may not be a carrier if she is: The biological mother of one son with hemophilia. The sister of a male with hemophilia. An aunt, cousin, or niece of an affected male related through the mother. A woman may or may not be a carrier if she is: 1  The biological mother of one son with hemophilia. 2  The sister of a male with hemophilia. 3  An aunt, cousin, or niece of an affected male related through the mother.  The biological grandmother of one grandson with hemophilia. Females can also have hemophilia, but this is much rarer. In such cases both X chromosomes are affected or one is affected and the other is missing or inactive. In these females, bleeding symptoms may be similar to males with hemophilia. A female with one affected X chromosome is a carrier of hemophilia. Sometimes a female who is a carrier can have symptoms of hemophilia. In addition, she can pass the affected X chromosome with the clotting factor gene mutation on to her children. Learn more about the inheritance pattern for hemophilia. Because carriers have one normal X chromosome which produces a certain amount of factor VIII or IX clotting factor, they are almost always protected from the most severe form of hemophilia in which the level of clotting factor is less than 1%. However, the variation in clotting factor levels in carriers is very wide. In this example, the mother is a carrier of the hemophilia gene and the father does not have hemophilia. 1  There is a 50% chance each son will have hemophilia. 2  There is a 50% chance each daughter will be a carrier of the hemophilia gene. Hemophilia is inherited in an X-linked recessive pattern. A condition is considered X-linked when gene mutation that causes it is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is enough to cause the condition. A genetic carrier is one who can have and pass on a gene without showing signs that they have it. Since hemophilia is an trait carried on the X chromosome and males have only one X chromosome if a male has the trait, they would in fact be symptomatic and therefore could not be a carrier by definition. Females, depending on how the dominance works out can either be symptomatic or asymptomatic.
Yes, Hemophilia occurs more commonly in males.