RAPID GENOTYPE ANALYSIS IN TYPE 2B VON WILLEBRANDS DISEASE USING A UNIVERSAL HETERODUPLEX GENERATOR

A new diagnostic technique based on DNA heteroduplex analysis has been used to identify specific point mutations in the von Willebrand's fac tor (vWF) gene of patients with von Willebrand's disease type 2B. Mole cular analysis in these patients has shown previously that their mutat ions are clustered in a short region of sequence in exon 28 of the VWF gene. The principle of the method involves heteroduplex formation bet ween amplified genomic sequence containing the defect and an exon 28 v WF gene universal heteroduplex generator (UHG). The UHG is a synthetic VWF gene exon 28 homologue which contains a specific heteroduplexes f or each type 2B mutation. Individual mutant genotypes are identified b y characteristic banding patterns following polyacrylamide minigel ele ctrophoresis. The technique is rapid, simple, inexpensive, and is idea lly suited for adoption by non-specialist haematology laboratories for screening purposes.