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Thirty four IIA vWD patients (16 from kindred I, 2 from kindred II and 17 unrelated patients) from 19 families were studied to compare multimer patterns using discontinuous SDS gel electrophoresis on a variety of agarose gels. Platelet multi-mers and effect of EDTA on plasma multimers were also studied in some.The large kindred and 9 other patients showed identical multimer and triplet abnormalities. The 11 other patients showed different multimer patterns either by having intermediate multimers or different triplet patterns. The second kindred had a similar triplet abnormality to kindred I but had intermediate multimers. Two other patients showed similar patterns except on 2% agarose gels when differences in the lowest multimer was seen. Of the 3 patients of YS, one showed the common IIA pattern but also had intermediate multimers, another had an unusually faint upper triplet band, while the third in addition to a faint upper triplet band with ESVWF 2+ had no identification of minor or major bands with ESVWF 10+ Another patient lacked high and some intermediate multimers but had a normal triplet pattern. The pattern we have seen in Kernoff's patient (1) still appears unique. In kindred II abnormal triplets persisted and high multimers appeared in EDTA plasma. In kindred I (and similar patients) intermediate multimers and a change in triplet pattern was observed in EDTA while lysed platelets showed an abnormal pattern different to the plasma one.This emphasizes the heterogeneity of IIA vWD and the need to consider multimer deletion, triplet pattern, platelet multimers, effect of EDTA in trying to subclassify in order to study structure function relationships of vWF.1. Kernoff PBA, Gruson R, Rizza CR. (1974) A variant of factor VIII related antigen. Br. J. Haematol. 26: 435.+ESVWF 2 and 10 are monoclonal antibodies to vWF epitopes.

The propositus, female aged 1 year, was investigated because of severe bruising. Bleeding time (BT) was in excess of 20 mins, VIIIC Multimeric analysis was not possible on the propositus, but was normal in the plasma of all other family members. The father of the propositus, however, had an abnormal multimer pattern on lysed platelets, in that the faint low molecular weight doublet is absent and a dense band in the position of the lower band of the doublet with anodal and cathodal trailing.The maternal grandmother and mother appear to have asynpto-matic type I vWD and the father possibly has asymptomatic type I together with an alteration in the biologically vWF site with loss of the ristocetin site. This abnormality is not seen in his parents and his daughter possibly has type III vWD. The propositus' father although having some similarities to the patient of Howard et al., is different in other aspects.1. Howard MA, Salem HH. et al. (1982) Variant von Willebrand's disease Type B - Revisited. Blood, 60: 1420-1428.

Factor VIII related activities and factor VIII related antigen multimeric analysis have been assessed in two sporadic and eleven epidemic cases of haemolytic uraemic syndrome. In all patients factor VIII related antigen was raised and had an abnormal multimer pattern at presentation. The return to normal of factor VIII related antigen values and multimeric analysis patterns paralleled clinical improvement and, therefore, may be useful in monitoring patients with haemolytic uraemic syndrome. We postulate that endothelial cell damage releases the abnormal high molecular weight factor VIII related antigen multimers and that this may cause platelet agglutination in vivo.

A family is described in which the mother is a haemophilia carrier, the father has asymptomatic type IIA von Willebrand's disease, and their second son has simultaneously inherited both severe haemophilia and type IIA von Willebrand's disease. This is the first report of both diseases occurring simultaneously. The inheritance patterns and laboratory data on the family are presented and discussed.