Von Willebrand's disease was first identified in 1926 by Erik von Willebrand, a doctor from Finland who noticed a new type of bleeding disorder among people living on a group of islands between Finland and Sweden. Between 1 and 3 per cent of the UK population is thought to suffer from this inherited illness, in which one of the proteins that help blood to clot is at low levels, abnormal or almost absent; but most people have never heard of it.
It affects men and women equally, and can cause heavy periods, nosebleeds, and bleeding after surgery. Sufferers often bruise easily. The good news is that most cases are mild, and easily treatable with drugs or a transfusion of the missing factor. However, it is often difficult to diagnose.
Professor Christine Lee, of the haemophilia centre at the Royal Free Hospital in London, has ran a study among women who contacted a gynaecology clinic complaining of heavy periods. She asked them to fill in a pictorial blood loss chart and tested 150 women with heavy loss for bleeding disorders. Of those tested, 13 per cent were found to have von Willebrand's disease.
Prof Lee also discovered that using a nasal spray containing DDAVP (see treatment panel) cut down women's blood loss and the length of their periods. The nasal spray is currently available only from specialist haemophilia treatment centres for named patients, as it is still undergoing clinical trials.
Prof Lee hopes to run a second study into the incidence of von Willebrand's disease among women students at Oxford University. "The trouble with von Willebrand's is that it causes ill health," she says. "People can suffer from anaemia, and healing after surgery or injury takes longer and provides a site for infection."
Although it affects both sexes, it is more of a problem for women because of the debilitating effect of heavy periods. And although pregnancy raises levels of von Willebrand's to normal, they can fall quickly after childbirth, and cause haemorrhage. Men don't usually have as many problems, unless they need surgery.
More than 70 per cent of those with von Willebrand's disease have the mild type 1, where there is a low level of the von Willebrand protein. Type 2, where the von Willebrand factor is abnormal or does not work properly, and type 3 where it is almost absent, are more unusual. Type3, which is more severe, is thought to affect only 1 in a million people.
General testing is "fraught with disaster", says Dr Trevor Baglin, consultant haematologist at the haemophilia centre at Addenbrookes Hospital, Cambridge. An individual's bleeding can be influenced by up to 50 factors, including blood group, fear, stress and pregnancy, and the von Willebrand protein level varies in response.
"In some people, even the stress of having the blood test can bring the von Willebrand factor up to normal levels. If a bloke goes out on a football field, and starts running around, his von Willebrand factor could be 100 per cent," Dr Baglin said.
"In surgery, the trouble is that, if you have general anaesthetic and your body is relaxed, your von Willebrand factor may only be 25 per cent."
The answer has always been to take repeated blood tests, which places a burden on overstretched laboratories, and to examine a patient's clinical history. But that could change, as people with von Willebrand's disease could soon benefit from genetic testing.
Doctors at the University of Sheffield's division of molecular and genetic medicine are applying for European funding to develop a genetic test using computers. "We can do the test at the moment, but it is very laborious," said Prof Ian Peake. The von Willebrand gene is large, and finding the defect involves painstakingly sorting through DNA. "If we can find a way of sequencing DNA... so that it is automatic and quick, we can get a precise diagnosis." But it will be some years before the test is routinely available.
"It's like saying you have a car that will go at 200mph. They're expensive to make at first; later on they become more common, and the cost of producing them goes down."
Tranexamic acid: Helps stop bleeding by slowing down the body's process of breaking down blood clots. Taken as a tablet, medicine or mouthwash. May cause stomach upsets.
DDAVP or desmopressin: A copy of the body's hormone which raises the level of von Willebrand protein. Given by drip, injection or nasal spray. Can cause flushing, headache and water retention.
Clotting factor concentrates: Given to people with very low levels of the factor or those needing major surgery. Made of screened plasma from blood donors to replace the missing factor. Von Willebrand patients who need blood products have to be vaccinated against hepatitis A and B.Reuse content