Per general etiquette, the mother of the bride buys her wedding day outfit first, then notifies the mother of the groom about the color, length and overall formality of her choice. But if the groom's mom doesn't get word by the four-month mark, she should touch base with the bride-to-be about what to do.
Genetics. The two main types of hemophilia are caused by gene mutations that affect the levels of clotting factors in the blood. Mutation of the FVIII gene leads to hemophilia A, also called classic hemophilia, while a mutations in the FIX gene leads to hemophilia B, also called Christmas disease.
Example: Hemophilia A. Hemophilia A is an X-linked recessive disease caused by a lack of a coagulant, or blood clotting agent, called factor VIII (factor 8). This is caused by a mutation in a gene on the X chromosome called F8.If a father is affected, his daughters will be carriers of hemophilia A and his sons will be unaffected.or an X-linked dominant condition, only one copy of a gene on the X chromosome whether in a female with two X chromosomes or males with on X chromosome must have a change or mutation for an individual to be affected with the condition.