No abstract

Phenotypes and gene frequencies are presented for 20 serum and erythrocyte proteins in two Amerindian populations of inner French Guiana. No genetic variability was detected in 12 of these systems. Heterozygosity was calculated for the others and the reasons for its variation are discussed.

Simultaneous subtyping of two genetic markers--group-specific component (Gc) and transferrin (Tf)--by electrofocusing enabled us to compute the following gene frequencies for the Tunisian population: Gc1S, 0.525; Gc1F, 0.260; Gc2, 0.215; TfC1, 0.770; TfC2, 0.215; TfD1, 0.015. The frequencies of TfD, TfC2, and Gc1 are higher than those found in Caucasoid populations and can be explained by Negroid contribution. A selective advantage related to the metabolic role of this vitamin D-binding protein does not seem very likely for any particular Gc type or subtype. It is postulated that the differences in the frequencies of the Gc alleles might be related to selective advantage for genes belonging to other genetic systems originally closely linked to either Gc1 or to Gc2 alleles.

No abstract

HLA—A, B. C. DR, MB, Bf, Gm, Am, Pi and Km genes (and 12 erythrocyte genetic systems) have been analyzed and correlated with clinical or biological features in 88 mesangial IgA glomerulonephritis. These data pointed out 2 gene frequency modifications: a significant MB1 specificity decrease in the total patient group and a significant Km I increase in the chronic renal failure mesangial IgA nephropathy subgroup.