Are there carrier forms and or lethal forms of hemophilia?

Answer 1

Some women are carriers and there are 3 different types of hemophilia (A, B, & C) plus Von Willebrand's disease.

The reason that females are carriers is that the defective gene that results in the clotting factor deficiency is located on the X chromosome and is passed on by the mother to daughter or to son. It can't be passed on from father to son but can be passed from father to daughter. I'll explain below.

Understand something about genetics: Women carry two X chromosomes (XX) and men carry one X and one Y (XY). There must be two X s to make a female baby but only one Y is needed to make a male. Each parent contributes one chromosome to a baby. Because the mother will always contribute X chromosomes, it's the father who determines the sex of the baby and he does this by contributing either an X or a Y chromosome. Since the defective gene is on an X chromosome, when it comes to male children it will be the mother who passes on the gene. A mother may pass on the defective gene to her daughter and as long as the father isn't a hemophiliac himself, he won't contribute a second defective X gene and the daughter will just be a carrier and won't have the condition herself. If the father has hemophilia and the mother is a carrier, the daughter ends up with two defective genes and she WILL have hemophilia. This applies only to A & B, the more common forms. These occur, by far, mostly in males but they CAN and HAVE occurred in females. The gene that causes C can be passed on by either parent.

Hemophilia A: Low or no levels of clotting factor VIII. This is the most common from of hemophilia, the "classic" form. There will be prolonged bleeding even minor cuts and wounds. The largest and most common problems are internal bleeding into the joints, organs and even muscles.

Hemophilia B: Low or no levels no clotting factor IX. This form is less common than A, but leads to similar bleeding concerns.

Most people with hemophilia can lead relatively normal lives if they exercise care and caution combined with prompt and adequate treatment.

Hemophilia C: Low or no levels of clotting factor XI. This is the rarest form of the three. Unlike A and B, the risk for bleeding isn't influenced by how severe the XI factor deficiency is and this makes it more difficult to manage. Most people with the C type don't bleed spontaneously but do have unpredictable bleeding tendencies after surgery or trauma. And unlike A and B, this form affects males and females equally of Ashkenazi or Iraqi Jewish descent.

Von Willebrands disease: Technically this isn't hemophilia but because it's a bleeding disorder, I included it. It's caused by a deficiency in a clotting protein called Von Willebrand factor and this disease affects both males & females equally, unlike hemophilia.

Any hemophilia, A, B or C, is potentially lethal given the nature of the deficiency. Bleeding from head trauma poses serious risk as does bleeding into any of the vital organs.

Answer 2

Yes, hemophilia can have carrier forms where individuals carry the gene but do not display symptoms, typically females. Lethal forms are rare and usually occur in severe cases of hemophilia where spontaneous bleeding into critical organs can be life-threatening.