Haemophilia

Haemophilia is an inherited condition that affects the blood’s ability to clot.

Haemophilia A (clotting factor VIII deficiency) is the most common form of the disorder, present in about 1 in 5,000–10,000 births.

Haemophilia B (factor IX deficiency) occurs in around 1 in about 20,000–34,000 births. Haemophilia is more likely to occur in males than females. This is due to the fact that females have two X chromosomes while males have only one, so the defective gene is guaranteed to manifest in any male who carries it. As females have two X chromosomes, the chance of a female having two defective copies of the gene is very rare, so females are almost asymptomatic carriers of the disorder.

Haemophilia lowers clotting factor levels of the coagulation required for a normal clotting process. Thus when a blood vessel is injured, a temporary scab does form, but the missing coagulation factors prevent fibrin formation, which is necessary to maintain the blood clot. Hemophiliac does not bleed more intensely than a person without it, but can bleed for a much longer time. In severe hemophiliacs even a minor injury can cause lot of blood loss which can last for days or weeks, or even never healing completely. In areas such as the brain or inside joints, this can be fatal or permanently debilitating.