ERGIC-53 gene structure and mutation analysis in 19 combined factors V andVIII deficiency families

Combined factors V and VIII deficiency is an autosomal recessive bleeding d isorder associated with plasma levels of coagulation factors V and VIII app roximately 5% to 30% of normal. The disease gene was recently identified as the endoplasmic reticulum-Golgi intermediate compartment protein ERGIC-53 by positional cloning, with the detection of two founder mutations in 10 Je wish families. To identify mutations in additional families, the structure of the ERGIG-53 gene was determined by genomic polymerase chain reaction (P CR) and sequence analysis of bacterial artificial chromosome clones contain ing the ERGIC-53 gene. Nineteen additional families were analyzed by direct sequence analysis of the entire coding region and the intron/exon junction s. Seven novel mutations were identified in 10 families, with one additiona l family found to harbor one of the two previously described mutations. All of the identified mutations would be predicted to result in complete absen ce of functional ERGIC-53 protein. In 8 of 19 families, no mutation was ide ntified. Genotyping data indicate that at least two of these families are n ot linked to the ERGIC-53 locus. Taken together, these results suggest that a significant subset of combined factors V and VIII deficiency is due to m utation in one or more additional genes. (C) 1999 by The American Society o f Hematology.