Gm, Am and Km immunoglobulin allotypes of two populations in Tunisia

Abstract

Gm, Am and Km allotypes were investigated in two Tunisian populations (236 samples from Mahdia and 142 samples from Sfax). These populations descend from immigrants and, therefore, the results were compared with those obtained in other populations living in the Near East and in North Africa. The subclass heavy chain allotypes G1m, G2m, G3m and A2m are inherited in fixed combinations. There were five main and four minor Gm-Am haplotypes that could be deduced from the phenotypes. This led to the conclusion that the populations studied are Caucasoids with some African admixture (about 10%) and a very low oriental contribution. Furthermore, there were 11 samples which showed 8 uncommon Gm-Am phenotypes. These could be explained by the assumption of five different uncommon Gm-Am haplotypes. Four of these may have arisen by equal crossing over of prevalent haplotypes. The fifth may be the result of unequal crossing over of prevalent haplotypes. The fifth may be the result of unequal crossing over, since it was proven, by family study, that more markers are transmitted together than are present in the prevalent haplotypes.

Twenty Nuclear DNA Polymorphisms in a Moroccan Population: A Comparison with Seven Other Human Populations

“…0.050). These results agree with previous genetic studies (Lefranc et al 1979;Bosch et al 2000;Dios et al 2001), even though our estimate is clearly lower than that from blood groups in Algeria (Aireche and Benabadji 1988). The remarkable sub-Saharan contribution (25%) found in this study points to remarkable gene flow that might have been particularly important before the formation of the Sahara Desert (5000 years BP, Said and Faure 1990), although the historical role of north-south trade routes cannot be discarded.…”

Genetic diversity in Northern Spain (Basque Country and Cantabria): GM and KM variation related to demographic histories

“…Some uncommon phenotypes, all of them previously reported [32][33][34]11 [GM(1,2,3,17;23;5*), GM(3;23;5*,21,28) and GM(1,3;…;5*,21,28) in Alava; GM (1,3,17;23;21,28) and GM (1,3,17;23;10,11,13,15,16) in Montes de Pas], were excluded from haplotype calculations, except for the carriers of haplotype GM *1,17;23;21,28, one of the most frequent among the rare haplotypes. In all cases, phenotype distributions showed no significant deviations from the HardyWeimberg equilibrium.…”

The genetic diversity of three peculiar populations descending from the slave trade: Gm study of Noir Marron from French Guiana

“…Data on Gm allotypes of human immunoglobulins in African populations and other populations have been previously reported [16][17][18][19][20][21][22][23][24]. The Gm system has been frequently studied in human populations, due to its heterogeneous haplotype frequencies among populations [25][26][27], and is thus very useful to assess genetic relationships among populations in a given geographic area [28][29][30] or from different geographic areas [23,31,32]. Its high power of discrimination is relevant for the aims of this study.…”