Typing for MLC determinants using lymphocytes from cousin-marriage offspring as typing cells

A first cousin marriage family with three children was studied. One sibling (AW) was homozygous for W32.W10. When used as stimulator in one way MLC, AW elicited a very low response in family members possessing this haplotype. Serologically identical sibling and father combination showed bidirectional non-stimulation in one way MLC. Therefore, AW is assumed to be homozygous not only for SD antigens, but also for LD determinants which we call LD W10a. Among the 43 unrelated individuals tested with AW, an association between LD W10a and W10 antigen of the second HL-A locus was observed. Of 12 W10 positive individuals tested, five carry this allele as compared to one out of 31 W10 negative individuals. The data suggest a strong linkage disequilibrium between the FOUR locus determinant W10 and LD determinant LD W10a.