The Gm Serum Factor in Japanese

Abstract

The Gm serum factor (Gm^a) was described by Grubb in 1956. He observed that the pooled human γ-globulin will inhibit the agglutinating activity of selected rheumatoid arthritis patient s serum against the red cells coated with selected incomplete anti-Rh. With the same technic, he furtherde. monstrated that individual human serum can be grouped in two phenotypes, Gm (a+) and Gm (a-), depending on presence or absence of the inhibitor or Gm^a factor in the serum under test. The factor is associated with γ-globulin and genetically controlled. Up to date, the data on the Gm factor are rather limited, but there is a good evidence to assume the racial difference of the factor in its distribution. Thus it has an incidence of abaut 60% among European Caucasoids, 95% among Esquimaux and 100% among African Negroes. The assumption was further supported by the following investigation on Japanese. Over 800 serum specimens obtained from blood donors were studied and more than 98% of thepopulation in Tokyo and Kumamoto districts was found to carry the Gm^a factor. It was also recon-firmed that the factor is apparently transmitted as a dominant Mendelian charctor. Since the Gm factor is genetically tranmitted, Gm grouping may be applied to human genetics, forensic medicine and anthropology as a useful adjunct to the usual blood grouping procedures.