The kell system in Senegal: phenotype and gene frequencies

The Kell gene frequencies, determined in Senegal are as follows: Our data enter the limits already known for black African populations.     

Genetic variation in Arizona Mexican Americans: estimation and interpretation of admixture proportions

Mexican Americans are a numerous and fast growing ethnic population in the United States. Yet little is known about their genetic structure. Since they are a hybrid, it is of interest to identify their parental populations and to estimate the relative contributions of these groups. This information is relevant to historical, biomedical, and evolutionary concerns. New genetic typings on 730 Arizona Mexican Americans for the HLA-A, HLA-B, ABO, Rh, MNSs, Duffy, Kidd, and Kell loci are presented here and they are used to estimate ancestral contributions. We considered both a dihybrid model with Amerindians and Spaniards as proposed ancestors, and a trihybrid model with Amerindians, Spaniards, and Africans as proposed ancestors. A modified weighted least squares method that allows for linkage disequilibrium was used to estimate ancestral contributions for each model. The following admixture estimates were obtained: Amerindian, 0.29 +/- 0.04; Spaniard, 0.68 +/- 0.05; and African, 0.03 +/- 0.02. The interpretation of these results with respect to Amerindian and Spanish ancestry is straightforward. African ancestry is strongly supported by the presence of a marker of African descent, Fy, despite the fact that the standard error of the estimate is as large as the estimated admixture proportion. An evaluation of the sensitivity of these results to a number of variables is presented: 1) our choices of ancestral allele frequencies, 2) the possibility of selection at HLA and the blood groups, and 3) genetic drift in Mexican Americans.     

Genetic polymorphism (ABO, Rh, Kell) in Kabul (Afghanistan)

ABO, rhesus and Kell blood group data on 1327 donors in Kabul are analysed by ethnic affinity and compared with existing data on Afghanistan peoples. Blood group frequencies are very similar in Pushtu and Tadjik, despite their different historical, linguistic, and cultural backgrounds. Inclusion of the small sample of Hazara in the analysis shows overall heterogeneity in rhesus D, E, and e frequencies, suggesting the existence of a broader pattern of genetic variation among the peoples of Afghanistan.     

A survey of phenotype distribution of subgroup A2, blood groups MNS, P, and Kell in the Kazak nationality living in northern Xinjiang of China

The research was undertaken to study the phenotypic polymorphisms of the subgroup A2, blood groups MNS, P, and Kell in the Kazakh population in northern Xinjiang, China and establish data on rare blood group antigens in the Kazakh population, in order to provide references for clinical blood transfusion safety and prevention of hemolytic disease of the new born. In this study, 6,862 unrelated Kazakh individuals in northern Xinjiang were randomly selected, and their blood samples were collected for serological testing. The antigens of A, B, A1, M, N, P1 and K were detected by serological saline tube method, and the antigens of S, s, and k were detected by the microcolumn gel antiglobulin card method. The results were as follows: ① The detection rates of subgroup A2 in group A and group AB were 7.08% and 21.79%, respectively; ② The allele frequencies of the blood groups MNS, P and Kell were M=0.5668, N=0.4332, S=0.1860, s= 0.8140, P1=0.2848, P2=0.7152, K1=0.0096, K2=0.9904. The observed values and expected values of frequency distribution of genotypes were compared by χ² test, which conformed to the Hardy-Weinberg genetic law (P>0.05); ③ Fourteen cases of S^-s^- rare phenotype were detected in MNS blood group system, with a frequency of 1.16%; ④ The frequency of K antigen in the Kell blood group system was 1.92%. One case of rare KK homozygote was detected, with a frequency of 0.034%. Our study suggested that the distribution of gene frequency of subgroup A2, blood groups MNS, P and Kell in the Kazakh population in northern Xinjiang has its own characteristics, and their blood group MNS has unique genotypes. The positive rate of K antigen of blood group Kell in the Kazakh population was significantly higher than Chinese Han population.     

Frequencies of ABO, Rh and Kell phenotypes in couples from Han, Kazak, Uyghur and Hui in Xinjiang: an inheritance simulation model for blood group incompatibility in new-born

The Xinjiang region with residents from more than 13 minorities represents an area of many diverse ethnicities. This ethnic diversity in relation to their blood groups and immune status may have a consequential impact on the clinical status of married couples. To evaluate the risks of haemolytic disease in new-born infants, we investigated the rate of blood-group incompatibility among 487 married couples from four ethnic minorities, namely the Han, Hui, Uyghur and Kazak populations. Han minority married couples showed significantly different ABO, Rh and K phenotype frequencies between marrial relationship, whereas there was no significant difference in ABO, Rh and K phenotypes between the Uyghur, Hui and Kazak .There was a significant difference between ABO blood types in Han married couples, in the Kazak Rh-C phenotype and in the Uyghur Rh-D phenotype. The Hui married couples only demonstrated ABO, Rh and K phenotypes. The Hui minority showed the highest incompatibility rate for Rh-C and Rh-E phenotypes between mothers and their new-born infants. The highest incompatibility rate for the ABO phenotype occurred in the Kazak group. These results particularly demonstrate the clinical issues relating to ABO and Rh incompatibility, in the Kazak and Hui minorities, respectively.     

Frequencies of RhCE and Kell phenotypes in Xinjiang using a cross-minorities transfusion simulation model

Xinjiang represents one of the richest minorities’ areas in China. This high ethnic diversity reflects in the blood groups and immune status and has a consequent impact on blood transfusions. To evaluate the risks of cross-minority transfusion in Xinjiang, we investigated the frequencies of erythrocytic Rh and K antigens among 1,073 Uyghurs and 213 Kazaks. We further reviewed the literature on the frequency of erythrocytic antigens to develop a simulation model for calculating the risk of patients in Xinjiang exposed to mismatched erythrocytic antigens. The frequencies of RhE, RhC, and K phenotypes were as follows: C antigen, 52.3% in Uyghurs and 56.8% in Kazaks; c antigen, 47.7% in Uyghurs and 43.2% in Kazaks; E antigen, 25.5% in Uyghurs and 27.2% in Kazaks; e antigen, 74.5% in Uyghurs and 72.8% in Kazaks; K antigen, 1.8% in Uyghurs and 1.8% in Kazaks. The population-adjusted cumulative match rate demonstrated that 53.3%, 51.4%, 50.6%, and 53.7% of the Uyghur, Kazak, Han, and Hui populations were recipients, respectively, although the recipients were transfused with an unknown Rh blood type. We concluded that the risks of cross-minority transfusion in Xinjiang are insignificant. The best strategy appears to be K and Rh-matched transfusions in this region due to the much higher frequency of the K antigen compared to other areas in China.