VWD reflects the impaired activity of a vital blood component termed von Willebrand factor (vWF), involved in the repair mechanism that is normally induced after a blood vessel is damaged. The disease has mainly 3 types. Type 1 is characterised by a reduction in vWF levels, type 2 by structural alterations of vWF in the blood and type 3 by a complete absence of vWF. The EU's MCMDM - 1VWD project focused on type 1 VWD, which has the broader prevalence among VWD patients. The aim was to identify novel markers for accurate diagnostic products and ways to improve on current management approaches. The basis of the project was the recruitment and characterisation of type 1 VWD families in order to address the project's objectives. A total of 154 families were identified. All blood plasma and DNA samples were collected and stored on a newly constructed database alongside genetic and phenotypic data. Family members were asked to fill out a questionnaire relating to a measurable clinical assessment of affected individuals in terms of bleeding severity. Molecular investigations included the examination of vWF binding to a variety of factors and how this was affected by the onset of disease. Genetic analysis revealed linkages between type 1 VWD and a specific vWF gene in 59% of the informative families. Further gene mutation studies showed that mutations in the vWF gene were the major cause in VWD and as such, mutation analysis should form a fundamental part of disease diagnosis. Further research is required in order to identify the exact nature of these mutations and how they affect gene expression and subsequently vWF levels in blood. These data could be of particular interest to clinicians active in that area of research and also to diagnostics companies.