A new human allotype carried by the γG3 subclass: Gm(25)
SummaryThe Gm(25) allotype has been tested on sera from various populations. It is closely related to Gm(5), Gm(10), Gm(11), and Gm(14) in Caucasoids, and to Gm(10) and Gm(11) in Mongoloids, but it distinguishes itself in Negroids where the Gm(5, 10, 11, 14,-25) phenotype is present with a frequency depending on the regions studied. It was demonstrated to be carried by the Fc fragment of γG2 Gm(5, 10, 11, 14). In a Caucasoid family it was possible to demonstrate the transmission of a rare gene, Gm1,10,11,17, 25. Among Old World Monkeys Gm(25) is present in Baboons and absent in Cercopitheci.RésuméL'allotype Gm(25) a été étudié sur des sérums de populations variées. Il est lié aux Gm(5), Gm(10), Gm(11) et Gm(14) chez les Blancs, aux Gm(10) et Gm(11) chez les Jaunes, mais il s'en distingue chez les Noirs où se retrouve le phénotype Gm(5,10,11,14,-25) avec une fréquence variable selon les régions. Il est présent sur le fragment Fc des γG3 Gm(5,10,11, 14). Dans une famille Caucasoide nous démontrons la transmission du rare gène Gm1,10,11,17,25. L'étude sur des Singes de l'Ancien Monde démontre que le Gm(25) est présent chez les Babouins et absent chez les Cercopithèques.
A GENETIC STUDY OF THE ANTIGENS ASSOCIATED WITH THE GM(B) FACTOR OF HUMAN GAMMA GLOBULIN.
SEVERAL ALLELES at each of two independent loci determine hereditary factors in human gamma globulin (review in Steinberg, 1962b). The alleles at one locus, Gm, determine hereditary factors in the heavy (H) chain of 7S gamma globulin (synonyms Y2, 7Sv88 ). (See Lawler in Cohen, 1963; Polmar and Steinberg, 1964.) One of these factors, Gm(b), may be determined by any one of at least four different alleles. In Caucasoids, it is determined by the allele Gmb; in Negroids by either a Gmab or a Gmabc allele, and by a different Gmab allele in all other races tested to date (Harboe, 1959; Steinberg, Stauffer, and Boyer, 1960; Steinberg and Wilson, 1963a). Evidence has been accumulating since 1961 that each of these alleles determines a Gm(b) factor which is composed of a series of antigens (see Ropartz, Rivat, and Rousseau, 1963, for review). Ropartz, Rivat, and Rousseau (1963) demonstrated that seven antisera which gave concordant results for Gm ( b) in whites gave three different patterns of reactions in Japanese. For convenience they called these patterns Gm(ba), Gm(b,8) and Gm(by). These patterns, however, were not the same for isolated individuals of other races. Indeed two French individuals also showed discordances in that they were Gm(b+) with some of the antibodies and Gm(b-) with others. Ropartz and his colleagues had no families to study; hence they could offer no genetic hypothesis to explain their results. A similar demonstration of different Gm(b) factors in whites was presented in data for an English family studied in this laboratory (Steinberg, Stauffer, and Dunsford, 1963). These observations raised the question of what relation the different Gm(b) antigens bear to the known alleles which produce the Gm(b) factors and whether these antigens define new alleles. This communication is a report of population and family studies with four anti-Gm(b) antisera. The studies were done to obtain answers to the above questions.
A New Allele within the Gm System ?
1959 Harboe [5] reported the finding of a new “antibody” which reacted antithetically to anti-Gm(a), the corresponding serum factor of which he designated Gm(b). At present the known Gm factors comprise Gm(a) (Grubb [2], 1956, Grubb and Laurell [3], 1956), Gm(x) (Hurboe and Lundevall [4], 1959), Gm(b) (Hurboe [5], 1959), Gm(R) (Fudenberg [l], 1960) and further a Gm-like factor (Steinberg et al. [7], 1960). Not taking Gm(R) and Gm-like into account, the inheritance has been shown t o be compatible with the assumption of several allelic genes or possibly closely linked gene pairs, the most frequent genes being Gma, G m a and Gmb. An investigation of a family in which the rare phenotype Gm(a-x+b+) occurred (Henningsen and Nielsen, 1961) appears to indicate the existence of a rare gene or gene combinnation Gmbx. During the investigation of a large family material with regard to factors Gm(a), Gm(x) and Gm(b) one exception to the antithetical relationship of factors Gm(a) and Gm(b) has been ascertained. The phenotypes of the members of the family in question appear from the following pedigree :