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.
The protein involved with hemophilia A is factor VIII (factor 8) and with hemophilia B is factor IX (factor 9). Picture of the blood clotting process. Hemophilia A is caused by a mutation in the gene for factor VIII, so there is deficiency of this clotting factor. Hemophilia B (also called Christmas disease) results from a deficiency of factor IX due to a mutation in the corresponding gene. A condition referred to as hemophilia C involves a deficiency of clotting factor XI. This condition is much rarer than hemophilia A and B and typically leads to mild symptoms. It is also not inherited in an X-linked manner and affects persons of both sexes.