Genetic Markers of the Heavy Chain Subgroups of Human  G Globulin

More than twenty known genetic antigens have been delineated on the heavy chains of human γ globulin (Martensson, 1966; Natvig and Kunkel, 1967a). These are distributed among three different subgroups of γG globulin and have served as genetic markers for the elucidation of the relationship between the different structural genes that determine heavy chain synthesis (Kunkel, Allen, and Grey, 1964; Terry, Fahey, and Steinberg, 1965). Certain heavy chains have multiple genetic antigens in different areas which can be separated by papain splitting. Information concerning the genetic control of different portions of these chains can thus be obtained. Two new genetic antigens, Gm (n) and Gm (g), have proven of particular utility in understanding the differences between the subgroups (Kunkel, Yount, and Litwin, 1966; Natvig, 1966). Varying relationships between genetic markers in different populations and within certain rare families have offered evidence for recombination between the different cistrons involved. These studies...