Gender
Since males have only one X chromosome, which makes them more susceptible to carry the disease from their mother. If a male inherits a defective X chromosome, he will be born as a diseased individual. But females have two X chromosomes, which make them less susceptible to hemophilia than men. If a female carries one abnormal X chromosome, she will be born as a carrier of the disease due to the presence of recessive genes and may pass this gene to his son and will make him diseased. For a female to have this disease, it is essential to carry both the X chromosome with the defective gene. This situation is infrequent.