Genetic basis of cell surface polymorphisms encoded by the major histocompatibility complex in humans.

In this review, the authors have analyzed the relationship between molecularly defined HLA gene polymorphisms and the diversity of HLA antigens detected serologically and by T-cell allorecognition. Although many relevant publications were not included, examples of the studies described here provide evidence for the strong association between polymorphisms defined at the gene and at the cell surface product levels. The concordance between RFLP and alloantigenic reactivity patterns may represent strong linkage disequilibrium between specific restriction enzyme variations in the coding and noncoding regions. It has become apparent that the allelic variations detected by molecular techniques are far greater than those defined by serological and cellular typing. This observation provides an impetus to identify reagents which define additional cell surface polymorphisms potentially important in immunoregulation, disease susceptibility, and transplant immunity.