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.     

Selective interactions among Rh,ABO, and sex ratio of newborns

Summary The hypothesis that the Rh and ABO blood systems behave like the HLA system in relation to mother-conception tolerance-rejection mechanisms was tested in 25,501 mother-infant pairs. According to this hypothesis, heterozygotes carrying a paternal gene that is not present in their mother should be better tolerated than homozygotes. Significantly more BO infants born to AO mothers. AO infants born to BO mothers, Rh(+) heterozygotes born to Rh(-) mothers, and less significantly AO infants born to OO mothers confirm the hypothesis. Fewer homozygotes occurred in Rh(-) infants born to Rh(+) mothers and in O infants born to non-O mothers. Deviations from the Hardy-Weinberg equilibrium found in the ABO system were modified by the Rh and sex of the infant. These data strongly support the hypothesis that at least two feto-maternal systems influence the denstiny of pregnancies: the classical known incompatibility system which operates late in pregnancy and a new one which is based on the induction of maternal tolerance early in pregnancy: maternal tolerance seems to be better elicited by heterozygous eggs or embryos carrying a gene not present in the mother. The data also support the hypothesis that the sex ratio is influenced by feto-maternal tolerance-rejection mechanisms associated with the ABO and Rh systems.     

Association of ABO and Rh(D) blood groups with filariasis

ABO and Rh blood groups in 344 filarial patients and 320 controls matched with respect to age, community and residence are reported. An excess of B and a deficiency of AB was observed among the filarial patients. The relative risks for the B and AB were 1.53 and 0.36, respectively. Only males showed clearly significant risks. The Rh(D) blood groups revealed no association with filariasis.     

ABO and Rh blood groups in diabetes mellitus

The present investigation was conducted with a view to testing the hypothesis that there is some association between blood groups (ABO and Rh) and diabetes mellitus. 520 proven cases of adult diabetes mellitus from the Diabetic Clinic of Rajendra Hospital, Patiala, were studied in 1979-1980. A large sample of 6204 normal individuals studied by Jolly et al. (1969) for ABO and Rh blood groups was taken as control for comparison with the patients. There is a strong indication of an association of diabetes mellitus with blood groups, especially with A, AB and Rh-positive blood groups. The maximum differences are in the AB groups in the two series and minimum in the A group. Individuals with gene p seem to be more susceptible to this disease. Thus the association between blood groups and diabetes mellitus is not a chance finding, but implies an aetiological relationship.     

Haptoglobin polymorphism among fourteen populations of India

Haptoglobin (HP) is a serum protein that has the capability of binding the extracorpuscular haemoglobin released during haemolysis. It plays an important role in protection of haemolytic disease by reducing the oxidative and peroxidative potential at free haemoglobin. The present study was aimed to determine the prevalence of HP polymorphism among different Indian populations, anthropologically belonging to diverse ethnicity. The polymorphism was screened among 642 unrelated individuals belonging to 14 population groups of India including both tribal and non-tribal caste groups from different geographical regions of India with distinct linguistic affiliations. An attempt is also made to understand the distribution of HP polymorphism among the studied populations. The result reveals the HP gene to be polymorphic in all the studied populations. Except the two tribal populations (Thotis of Andhra Pradesh and Patelias of Rajasthan) and one caste population (Rajput of Himachal Pradesh), all the studied populations are found to obey the Hardy-Weinberg equilibrium. The significance of the present study is elucidated with the prevalence of high mutant HP*2 allele frequency in India. Selection could be one of the most plausible explanations for this high HP frequency because of its uniformly high occurrence among all the studied populations.     

Segregation distortion in Rh polymorphism

Segregation distortion for the Rh system is reported. Mother-infant pairs (1018 pairs) from maternity service divisions of government hospital and 216 complete families with a total of 692 children, of Visakhapatnam (Andhra Pradesh, South India) were typed for the D-d alleles of Rh system. The segregations analysis made by means of the T matrix method of ITO matrices, assuming Hardy-Weinberg equilibrium, reveals that: Rh-positive mothers produce fewer Rh-negative children with significance and Rh-negative mothers produce more Rh-positive children with less significance than expected in both the mother-child and family studies. This results in a reduction in the d allele from mothers to their children. Known Rh antigenic specificities and reproductive compensation do not explain the observed distortion. Other selectively acting forces probably linked to Rh compatibility system seem to be operating to gain d alleles to maintain Rh polymorphism.     

ABO,Rh(D) and haptoglobin distribution in a sample from the sultanate of Oman

The distribution of phenotypic frequencies of ABO, Rh(D) system and Hp polymorphism in a sample from Muscat, Oman, revealed the following gene frequencies: P=0.164, q=0.110, r=0.726; D=0.738, d=0.262; Hp¹=0.289 and Hp²=0.711. These frequencies are in good agreement with the distribution in the Euroasiatic continent.