Bleeding Disorders With No Family History
In some families, there is no known family history of a bleeding disorder. The disorder seems to appear from nowhere and the family is shocked and confused.
There are several reasons this could happen. First, the family may not know about or may have forgotten ancestors with the bleeding disorder. Second, the parents may have a very mild bleeding disorder that was never diagnosed. This can happen with two parents, both of whom have mild Type 1 VWD. They may not know they have a bleeding disorder. Their child can be born with Type 3 VWD, a very severe disorder. Third, a bleeding disorder may appear in families with no history of it if the normal gene suddenly becomes faulty (a spontaneous genetic mutation).
Normally, genes are exactly copied generation after generation. Sometimes, though, a gene may become flawed. It may give different or wrong directions to the body. This change in the gene is called a mutation. The change is permanent – the gene won’t be able to turn back to normal.
The effects of the faulty gene may be noticed right away. Or they might not be seen until the gene is passed on to a baby. So the change in the gene may have happened in the parent or in the baby.
The change in the gene can be caused by something in the environment. It also seems to happen without any clear cause. Since they are nature's way of bringing about change, not all gene mutations are harmful.