A new HLA-D specificity associated with DR blank: D-BON.

Since 1980, a DR blank specificity undefined by serology but known to segregate in families linked to DQw1 has been recognized. We describe a Caucasoid family, BON... where 4 among 8 children are homozygous for such a specificity; their cells can be used as homozygous typing cells and the specificity defined is provisionally called D-BON. There is no known consanguinity in this family. The homozygous D-BON cells carry DR molecules as shown by their reactivity with monomorphic anti-DR monoclonal antibodies. In a random family material consisting of 210 haplotypes, the gene frequency of D-BON is between 1 and 2%, which corresponds to about 40% of the DR blank frequency. The D-BON specificity seems associated with DQw1 and also with B35 and C4B2.