Bleeding disorders – Haemophilia A & B

Haemophilia is one of the most known bleeding disorders and come in three varieties; A, B and C. The disorder is where the sufferer’s blood cannot clot properly. This is due to a lack in clotting agents which are clotting proteins required to slow and stop bleeding.

An amusing urban legend is that those with haemophilia could bleed to death from a minor cut because we don’t clot and neither would we bleed any faster than others if injured. However, we do bleed for longer. The most obvious bleeding would be from cuts and grazes but the more troublesome bleeds are into muscles and joints happen are more frequent.

Haemophilia A and B are caused by a genetic irregularity commonly passed on from the mother (~70%) or can occur during a child’s development in the womb (~30%). Luckily the gene is a recessive one which helps your odds of not having an issue. It is also carried on the ‘forth leg’ of the X chromosome (much like that of the gene causing colourblindness) meaning that men are much more likely to suffer from the disorder. Please see the genetic table below to help understand how it can be passed on.

To expand on this, if the parents are a male sufferer and female carrier the 50% chance of sons being sufferers remains but daughters chances are 50% carrier and 50% sufferer. This is why it is extremely rare to find female sufferers. 1 in every 5,000 male births is a sufferer of haemophilia A and about 1 in 20,000 male births are sufferers of haemophilia B. I am sorry but I cannot any stats on female carriers.

Haemophilia affects clotting because the body produces platelets to protect itself from bleeding. These platelets carry many clotting proteins (known as factors) that are need to form a clot properly. These proteins work in a step by step basis and therefore is any factors are missing, it does not work. These factors are numbers in roman numerals from I to XIII. Sufferers of haemophilia A and B lack the clotting proteins factor VIII and factor IX respectively.

There are treatments for haemophilia and it depends on you level of severity as to whether you need daily treatment or only when injuries occur. The more sever, the higher the frequency you require treatment. These levels are:

• Normal range – 50% to 150% of normal factor activity in blood

• Mild haemophilia – 5% to 40%

• Morderate haemophilia – 1% to 5% (I am 3%)

• Sever haemophilia – <1%

Unfortunately the treatments do not come without risks. Some products used are made from plasma from donated blood. Unfortunately, before a blood surveillance system being implemented in 1998, many haemophilia sufferers had their lives take a turn for the worse when the blood donated was contaminated with Hepatitis or HIV. In turn, they contracted the diseases. The Haemophilia Society is still fighting in courts today for those affected to gain some compensation (more information on this can be found here). Another big complication is that your body can develop inhibitors to the treatment rendering it ineffective. Due to this, after each treatment (or annually depending on which is sooner) you are required to have a blood test to check this.

I hope this helps you better understand what haemophilia A and B are, how it affects lives and how it can be treated (following on from the last blog on first aid).