Red Cell Antigen Systems Research Articles

Genetic variation within the Hereford breed of cattle.

Genetic differentiation among Hereford populations from Britain, Ireland, Sweden, Canada and New Zealand together with six other beef breeds was assessed using blood type polymorphisms. Changes in the genetic structure of the British Hereford population over time were also examined. Loci surveyed were seven red cell antigen systems (A, B, C, F, L, S, Z), and two serum protein loci (transferrin and albumin). Within group variation was measured by the average expected heterozygosity, and between group relationships by genetic distance. There was significant genetic differentiation among Hereford populations from different countries. Differences between Hereford groups, however, were not as large as differences between breeds. There were also significance differences among British herds. The proportion of Canadian genes in the British 'hybrid' population was estimated to have increased from 0.42 (+/- 0.34) in the 1970s to 0.98 (+/- 0.11) in the 1990s. Canadian Hereford groups were found to be less heterozygous than other groups, and replacement of the British population with Canadian animals may lead to loss of variation. Breeding strategies that preserve original native genes in British Hereford populations should be considered by commercial breeders, in order to prevent the long-term loss of genetic variation within the breed.

Lack of alloimmunization to D antigen in D-negative immunosuppressed liver transplant recipients.

Orthotopic liver transplantation (OLT) sometimes requires large amounts of blood. An adequate supply of Rh-negative blood for Rh-negative patients is not always available. Seventeen Rh-negative patients, out of 327 receiving OLT in this hospital, received from 5 to 41 units of Rh-positive red cells during surgery. Each of the 17 patients was followed for 7 weeks to 70 months after OLT for detection of unexpected antibodies. Cyclosporin A and prednisone, azathioprine, and adjunctive rabbit antilymphocyte globulin or monoclonal OKT3 antibody were used to prevent graft rejection. Evidence of immunization, either to D or to antigens in the rest of the red cell antigen systems, did not appear in any patients. It is hypothesized that cyclosporin A affects the immune humoral response, inhibiting lymphocyte activation and the primary immune response; consequently, Rh-positive blood may be transfused to Rh-negative OLT recipients so treated with little or no risk of alloimmunization.

Contribution to study of Asmat genetic variability

During an anthropological survey in the South-West of Irian Jaya (Indonesian New Guinea), 145 blood samples were collected from the coastal Asmat population. ABO, MNSs, Rh, Kell, Duffy and Kidd red cell antigen systems were investigated and the results are presented here. ABO, MNSs, Rh gene frequencies of the Asmat, together with those of 21 other New Guinea populations, were examined by principal component analysis. The topological representation of the distribution of the selected New Guinea populations confirms high variability in the interior of the island, and possible causes are discussed. A hypothesis is advanced, concordant with language evidence which would explain the resemblance among populations from opposite coasts of New Guinea and between some mountain and coastal groups. When the comparison includes 32 other world populations, the New Guinea groups constitute one assemblage distinct from the others.

Genetic and environmental effects on the development of myopia in Chinese twin children

In order to assess the relative and interactive importance of genetic and environmental components on the development of myopia in Chinese school children aged from 10 to 15 years, a population-based sample of 361 same-sexed twin pairs recruited through stratified cluster sampling was studied. Zygosity of twin pairs was determined by Mendelian traits, red cell antigen systems, and continuous dermatoglyphic characteristics; while myopia was diagnosed by both objective and subjective techniques. Studying and reading habit was obtained from cotwins and their parents through a life style questionnaire. Age-sex-adjusted concordance rate derived from multiple regression equation was used in the analysis. Conventional comparison of intrapair concordance between monozygotic (MZ) and dizygotic (DZ) twins was used to assess the importance of a genetic component in the determining of myopia, and a significant genetic influence was observed. Environmental influence on myopia was evaluated through MZ cotwin method, and MZ cotwins with concordant studying and reading habits were significantly more concordant in myopia than those MZ cotwins with discordant habits. The possible effect of gene-environment interaction on myopia was explored, and concordance in myopia was found significantly associated with the interaction between zygosity and habit of studying and reading. These observations suggested that the impact of the environmental factor on the development of myopia may be influenced by genotype, and vice versa.

Red cell antigen, plasma protein and red cell enzyme polymorphisms in the island of Tasmania.

Blood specimens from 651 blood donors registered with the Hobart division of the Red Cross Blood Transfusion Service of Tasmania were examined for six red cell antigen systems, as well as two plasma protein and three red cell enzyme polymorphisms. The most distinctive feature is the relatively high frequency of the Rh haplotype cde. Subdivision of the sample, permitted via questionnaire data, indicated that donors born overseas exhibited the greatest differences from those born in Tasmania, but none were significant at the 5% level. Overall gene frequencies in Tasmanian donors, except for the Rh system, were very similar to those reported for Melbourne donors, and clearly reflect the known predominance of British and Irish immigrants throughout the period of white settlement on the island.

Laboratory evidence of unsuspected parental consanguinity among cases of disputed paternity

A search was conducted to find evidence of possible incestuous unions between the biologic parents of children involved in 2500 paternity cases. Suspicion was raised when either (1) a mother and her child possessed identical HLA phenotypes, or (2) the child appeared to be possibly homozygous for one maternal haplotype (i.e., one of the child's HLA haplotypes was a blank). These mother-child HLA-haplotype dualisms (MHDs) occurred in 5% of all cases. Frequency of exclusion of the accused men in cases demonstrating MHD, was compared with the remaining paternity cases. No significant difference was found in overall exclusion rates between MHD cases and controls when exclusion produced by HLA and red cell antigen systems were observed. However, there was a greater rate of exclusion in MHD cases when comparing exclusions produced by red cell antigen systems regardless of whether HLA tests excluded paternity ( p < 0.025). MHD cases involving teenaged mothers differed from control cases in frequency of exclusion of paternity only on the basis of red cell antigen phenotyping ( p < 0.005). The HLA system's usefulness in paternity testing is diminished when there is MHD; multiple, independently-inherited systems are relatively more useful in these circumstances. The search method detects only half of potential incest cases; proof of incest requires more extensive testing for homozygosity among other polymorphisms. Since calculations of likelihood of paternity are inappropriate in cases involving close consanguinity, detection and follow up studies are important. Data suggest that one-fifth of MHD cases may involve first degree consanguinity and that the incest rate among paternity cases may be as high as 2%.

Detectability of Selected Genetic Markers in Dried Blood on Aging

Abstract The detectability of selected blood genetic markers aged up to six months deposited on six substrata, glass, wool, nylon, and three types of cotton (plain cotton, permanent press, and denim), was investigated. The resulting dried blood specimens were aged at ambient temperature at 20 and 66% relative humidities; a few samples were aged at —20°C Analyses were performed on the samples kept blind for the investigators at 1-, 2-, 4-, 13-, and 26-week aging periods. Red cell antigen systems selected for this study were ABO, MN, Rh, Kidd, Duffy, and Kell. The most stable antigens were A, B, and O of ABO; M, N, and s of MN; and D of the Rh system. These variants were identified in specimens aged for 26 weeks at both low and high relative humidities. The least stable antigens, Jk a of Kidd, Fy a of Duffy, and K of the Kell systems, were detectable for only one week at either humidity level. Of these antigens, only Fy a and K aged at 20% humidity were detected at the two-week test period. Other variants (S of MN and C, c, E, and e of Rh) were detected for various lengths of time ranging from 2 to 26 weeks. In particular, Rh factors C, c, and E were affected adversely by high moisture environments. The four enzyme systems selected were adenylate kinase (AK), adenosine deaminase (ADA), phosphoglucomutase (PGM), and erythrocyte acid phosphatase (EAP). AK and PGM isoenzymes were still identifiable at 26 weeks, and ADA and EAP at 13 weeks for the low and high humidity storage conditions. PGM isoenzymes appeared to be more stable at low humidity, and ADA and EAP at high humidity. No obvious differences in detectability resulting from phenotype or substrate were discerned, except possibly for permanent press and denim, which appeared to shorten the detectability time of PGM. Storage of the specimens at —20°C generally preserved the antigens and the enzymes better than storage at room temperature. The discrimination probability was calculated on the basis of the genetic markers still detectable at the end of each aging interval. No test error was assumed, and frequency of occurrence data for each genetic marker were taken from the literature.

A Population Genetic Study of the Kota in the Nilgiri Hills, South India

A population genetic study among the Kota of the Nilgiri Hills, South India, involved tests for abnormal haemoglobins, 5 red cell antigen systems, 4 serum protein and 13 red cell enzymes systems. Twelve systems are invariant in the Kota. The most distinctive characteristics are extremely low frequency of the A1 gene and complete absence of A2 in the ABO system, r(cde) in the Rh system, LDH cal-1 among the enzyme systems as well as absence of abnormal haemoglobins. A comparison of gene frequencies in those systems, which show variation, suggests that the Kota are more similar to the Toda than to any other tribal or caste population of the area. Genetic distance as well principal component analysis also reveals that the Toda and Kota are close to each other, in agreement with tradition.

Enlargement of the Dombrock blood group system: the finding of anti-Do b .

Abstract. The finding of anti‐Doa, the antibody antithetical to anti‐Dob in the Dombrock blood group system, is here reported; its existence promotes Dombrock to fifth place amongst red cell antigen systems in order of potential usefulness in discriminating between white people.