Abstract
In a family with a paternal recombinant child between HLA‐D/Dr and GLO, PLT have been raised between HLA‐A‐B‐C‐D‐DR and Bf identical sibs. Since these sibs differ only within a region (0) between HLA‐D/DR and GLO and the centromere, these PLTs allow the typing of two new determinants differing from HLA‐D/DR, possibly alleles at a new locus mapping in a region outside HLA‐D/DR. A difference limited to this (3 region can induce a weak primary and a strong secondary MLR.