PB0294 - Mutation in von Willebrand Factor Propeptide Causes Type 1 VWD

Background: Mutations in the von Willebrand Factor gene are known to cause von Willebrand Disease (VWD). Here we present a case 23 year old woman with type 1 VWD who was found to have a mutation in the D1 domain of the vwf gene which is in the region of the propeptide. The patient presented to clinic with a history of heavy menstrual bleeding and oral mucosal bleeding with an ISTH BAT score of 8. She had a family history of type 3 VWD in her sister. VWF activity R:Co was 42% and VWF antigen of 41% and a FVIII activity of 74%. VWF activity to antigen ratio of 1.02. Bleeding symptoms and VWD testing were consistent with a diagnosis of type 1 VWD. Subsequent genetic testing sent through Versiti Wisconsin revealed a heterozygous mutation in vwf exon 3 c.107G>A p.Ser36Asn (p.S36N) which is in the VWF D1 domain within the cleaved VWF propetide.

Aims: Here we present a novel variant in VWF gene exon 3 c.107G>A p.Ser36Asn (p.S36N) which likely causes type 1 VWD in Humans.

Methods: Genetic Testing was sent to Versiti Wisconsin.

Results: Genetic testing revealed a heterozygous mutation in vwf exon 3 c.107G>A p.Ser36Asn (p.S36N) in a 23 year old woman with type 1 VWD.

Conclusion(s): A heterozygous mutation vwf exon 3 c.107G>A p.Ser36Asn (p.S36N) is likely the cause of type 1 VWD in one human patient. This variant is a missence variant within the cleaved VWF propeptide D1 domain.