UHG-BASED MUTATION SCREENING IN TYPE 2B VON WILLEBRANDS DISEASE - DETECTION OF A CANDIDATE MUTATION SER547PHE

We have recently described a novel mutation screening technique for th e diagnosis of type 2B von Willebrand's disease (vWD). Analysis involv es the use of a synthetic universal heteroduplex generator (UHG). To t est the validity of the technique, we have applied UHG screening to se ven type 2B vWD patients of previously unknown genotype. Characteristi c heteroduplex patterns for Arg543Trp and Va1553Met mutations were fou nd in three patients and one patient, respectively. A fifth patient ga ve a novel pattern and direct sequencing revealed a hitherto unreporte d candidate mutation (Ser547Phe) 8 bases downstream of an ''identifier '' deletion in the UHG molecule. The two remaining patients gave norma l heteroduplex patterns; an Arg578Gln mutation was identified by PstI digestion in one individual and no mutation could be identified in the sequence covered by the UHG in the final patient. Using a combination of UHG technology and restriction analysis, over 85% of type 2B vWD p atients can be rapidly diagnosed by genotype.