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DQ linkage disequilibrium in haplotypes defined in a large trihybrid pedigree
Abstracts
1.3-06
FURTHER HETEROGENEITY OF HLA-OR2 - “OR2.3”. H Mervart, KH Wong, N Sakahara and Z Ganton, National Reference Laboratory, The Canadian Red Cross Society and Irwin Memorial Blood Bank. Following the 10th International Workshop 2 splits of HLA-OR2, designated as DRwl5 and DRwl6, were provided with official recognition by the nomenclature committee. These 2 subtypes can be identified with workshop reagents included in either the core or antigenic sets. During the 10th Workshop we also indicated the existence of a third variant of the DR2 antigen designated as DR2.3. This observation was based on serological results obtained with a single panel cell tested We now report with both local alloantisera and workshop reagents. expansion of our initial observation to permit identification of 5 Studies with panel members who express this particular DR2 subtype. the families of 3 of these donors demonstrate that DR2.3 segregates with the parental haplotype. We have found that of the 420 panel members tested, 136 typed as DR2 (32.3%), 21 as DRwl6 (5.0%) and 5 as DR2.3 (1.2%). It is interesting to note that all of the DR2.3 donors share Filipino ancestry. It does not appear that this subtype is uniquely associated with a particular HLA haplotype. The DR2.3 panel cells can be identified with either 3 of our local alloantisera or with 10th Workshop reagents. The characteristic serological pattern of this variant is positive reactions with reagents that define DRwl6 while producing negative results with a selection of DRwl5 antisera. Comparison of the DR2.3 molecule with the other DR2 variants is currently being performed using other techniques.
1.3-07
HLA DR/DQ LINKAGE DISEQUILIBRIUM IN HAPLOTYPES DEFINED IN A LARGE TRIHYBRID PEDIGREE. Z Layrisse, B Carreno, N Wexler, E Garc'ia, Z Stoikow, and 0 Balb&. Laboratorio de Fisiopatologia. Instituto Venezolano de Investigaciones Cientzficas, Caracas-Venezuela. An extensive collaborative genetic linkage study is carried out among members of a large pedigree of interrelated individuals living in socially and geographically isolated communities in the western shore of Lake Maracaibo. As part of this study we have tested cells from 144 descendents of a single Huntington disease gene carrying progenitor using HLA serological reagents of the IXth and VIIIth International Workshops. The phenotypes were assigned after definition of antigens by microcytotoxicity and analysis of pedigree data. The aim of the study was to define haplotypes and DR/DQ associations and to confirm pedigree relationshipsusing at least 20 red cell and plasma markers to exclude cases of non-paternity. Fifty-two different HLA haplotypes were found, 77% of which were represented in at least 2 individuals. The 14 DR spy haplocificities defined at the IXth Workshop were present in these types with variable association to DQ antigens. Thus DR2 was foundwith DQwl and DQw3; DR4 with DQw8; DR5 withDQw7 or DQw8; DRwl3 with DQwl or DQwX. The most frequent haplotypes were A24 CwlB35 DR4 DQw8; A2 CwX B51 DRwl3 DQw7; A29 CwX B45 DRwlO DQwl and Aw33 Cw9 B8 DRwl2 DQw8. Most of the haplotypes and DR/DQ disequilibria observed have been described among Caucasoid, Negroid or Mongoloid populations and will be informative to define admixture and gene flow in these communities.
1.3-06
FURTHER HETEROGENEITY OF HLA-OR2 - “OR2.3”. H Mervart, KH Wong, N Sakahara and Z Ganton, National Reference Laboratory, The Canadian Red Cross Society and Irwin Memorial Blood Bank. Following the 10th International Workshop 2 splits of HLA-OR2, designated as DRwl5 and DRwl6, were provided with official recognition by the nomenclature committee. These 2 subtypes can be identified with workshop reagents included in either the core or antigenic sets. During the 10th Workshop we also indicated the existence of a third variant of the DR2 antigen designated as DR2.3. This observation was based on serological results obtained with a single panel cell tested We now report with both local alloantisera and workshop reagents. expansion of our initial observation to permit identification of 5 Studies with panel members who express this particular DR2 subtype. the families of 3 of these donors demonstrate that DR2.3 segregates with the parental haplotype. We have found that of the 420 panel members tested, 136 typed as DR2 (32.3%), 21 as DRwl6 (5.0%) and 5 as DR2.3 (1.2%). It is interesting to note that all of the DR2.3 donors share Filipino ancestry. It does not appear that this subtype is uniquely associated with a particular HLA haplotype. The DR2.3 panel cells can be identified with either 3 of our local alloantisera or with 10th Workshop reagents. The characteristic serological pattern of this variant is positive reactions with reagents that define DRwl6 while producing negative results with a selection of DRwl5 antisera. Comparison of the DR2.3 molecule with the other DR2 variants is currently being performed using other techniques.
1.3-07
HLA DR/DQ LINKAGE DISEQUILIBRIUM IN HAPLOTYPES DEFINED IN A LARGE TRIHYBRID PEDIGREE. Z Layrisse, B Carreno, N Wexler, E Garc'ia, Z Stoikow, and 0 Balb&. Laboratorio de Fisiopatologia. Instituto Venezolano de Investigaciones Cientzficas, Caracas-Venezuela. An extensive collaborative genetic linkage study is carried out among members of a large pedigree of interrelated individuals living in socially and geographically isolated communities in the western shore of Lake Maracaibo. As part of this study we have tested cells from 144 descendents of a single Huntington disease gene carrying progenitor using HLA serological reagents of the IXth and VIIIth International Workshops. The phenotypes were assigned after definition of antigens by microcytotoxicity and analysis of pedigree data. The aim of the study was to define haplotypes and DR/DQ associations and to confirm pedigree relationshipsusing at least 20 red cell and plasma markers to exclude cases of non-paternity. Fifty-two different HLA haplotypes were found, 77% of which were represented in at least 2 individuals. The 14 DR spy haplocificities defined at the IXth Workshop were present in these types with variable association to DQ antigens. Thus DR2 was foundwith DQwl and DQw3; DR4 with DQw8; DR5 withDQw7 or DQw8; DRwl3 with DQwl or DQwX. The most frequent haplotypes were A24 CwlB35 DR4 DQw8; A2 CwX B51 DRwl3 DQw7; A29 CwX B45 DRwlO DQwl and Aw33 Cw9 B8 DRwl2 DQw8. Most of the haplotypes and DR/DQ disequilibria observed have been described among Caucasoid, Negroid or Mongoloid populations and will be informative to define admixture and gene flow in these communities.