Evidence for nonlikage of genes for HLA and hereditary angioedema.

Since the genes for several disorders of the complement system have been found to be linked to the HLA loci on chromosome 6, studies of the inhibitor of the activated first component of complement (Cl INH) and HLA in two families with hereditary angioedema (HAE) were undertaken. A total of 17 individuals were found to be affected in these three-generation families. Evidence was provided against close linkage of the genes for HLA and HAE. Other genetic markers studied were generally noninformative, although evidence was obtained against close linkage of the loci for HAE and ABO and HAE and transferrins. The reliable identification of individuals affected with HAE by Cl INH assay provides potential for establishing linkage relationships in the various phenotypes of this dominantly inherited condition.