Hereditary angioedema: lack of close linkage with markers on chromosome 6, with data on other markers.

Members of two Australian families with type A Hereditary Angioedema (HAE), having affected individuals in three generations, were typed for a large number of genetic marker systems in a search for close linkage with the locus controlling C1 inhibitor (C1 inh). The evidence from both families indicated lack of close linkage with HLA or with the loci for Bf and GLO on chromosome 6. Very close linkage was also excluded between the locus for C1 inh and the loci for 6PGD, PGM1 and MNSs. The other markers were not informative, but data on all systems showing variation are reported. The publication of similar data for other kindreds will help to determine lod scores for the probability of linkage between the C1 inh locus and loci controlling common protein polymorphisms. Linkage studies of this kind could establish whether the loci controlling type A and B HAE are identical or separate.