“…Human leucocyte antigens or histocompatibility genes have been revealed to have so enormous polymorphism as well as important immunological functions, particularly surveillance of external agents against cell (Frelinger and Schreffer, 1975;Bodmer, 1972;Bodmer and Bodmer, 1978;Barnstable et aI., 1979;Dausset, 1981, andThomson 1981), that HLA could be very useful as a genetic marker to disentangle genetic mechanism involved in onset of disease, assuming that the association between HLA and disease was due to linkage disequilibrium.…”