ON THE RELATIONSHIPS BETWEEN THE γ-GLOBULIN GENES OF THE GM SYSTEM

Abstract

Gm types of sera from Causasians and Negroes, of myeloma globulins, and of specific antibodies were investigated. In particular the relationship between the recently identified gene Gmf and other Gm genes was analyzed. Caucasians were, with rare exceptions, either Gm(b+f+) or Gm(b[long dash]f[long dash]). In Negroes, on the other hand, type Gm(b+f[long dash]) was found to be common. No myeloma globulins appeared to contain the product of more than 1 of the 3 genes Gma, Gmb, and Gmf, even though the large majority of normal individuals, as well as myeloma patients, possess 2 or all of these genes. The types Gm([alpha]+b[long dash]f[long dash]) and Gm (a[long dash]b[long dash]f+) represented the 2 major groups among the gamma2-myceloma globulins; each comprised roughly 40%. The types Gm(a[long dash]b+f[long dash]) and Gm(a[long dash]b[long dash]f[long dash]) are minor groups. All Gm(x+) myeloma globulins were also Gm(a+). Approximately half of the Gm(a+) myeloma globulins were Gm(x+). In the majority, but not in all, of Gm(a+) sera the anti-Rh antibodies were clearly Gm(a+). Similarly, the anti-Rh antibodies of Gm(f+) sera were most often, but not always, also Gm(f+). In contrast, only a minor proportion of Gm(b+) anti-Rh sera sensitized red cells to anti-Gm(b).