Para-Bombay B phenotype: a rare ABH blood group variant at tertiary care hospital, Gwalior India

Background: The H antigen is the precursor substance for A and B antigens formation on red blood cells of an individual and absence of it is termed as H deficient phenotype. If H antigen is absent on both RBCs and secretions, and then the resulting blood group is a Classical Bombay phenotype with anti-H antibodies in their serum. If H antigen are absent on RBCs and present in secretions and plasma, the resulting blood group is Para-Bombay phenotype. Genetically Para-Bombay’s lack an active H gene (genotype is hh) but carry at least one Se gene (Secretor gene). Para-Bombay or red blood cell (RBC) H negative secretor individuals may or may not have anti-H in their serum. In both cases routine blood grouping is O. Case Report: Blood sample of 24-year-old female is submitting in blood bank, resulting her routine grouping O RhD positive. Complete blood grouping by Gel technology revels her forward grouping is Oh and reverse grouping B. Patient is secretor for B and H antigens. Absorption and elusion test is negative. Family grouping was also done to find out compatible blood and her family genesis. Conclusion: Patient blood group is Para-Bombay B. Complete blood grouping (Forward and reverse) as well as saliva grouping and absorption /elusion test is advisable when there is a discrepancy in ABH grouping.

The prevalence of secretor status and co-expression of lewis antigen in voluntary blood donors

Background: Blood group substances are present in soluble form in a majority of individuals in secretion such as saliva and body fl uids. Secretor status refers to the presence (SeSe and Sese) or absence (sese) of secretor gene which secrete ABH soluble substances. Secretor status can be used to resolve ABO discrepancies of people whose blood group cannot be identified by routine blood grouping and it can also help in identifying patients who may be a high risk group for getting certain diseases. Aims and Objectives:Our aim and objectives of the study is to fi nd out the Prevalence of Secretor Status and Co-expression of Lewis Antigens among the Voluntary Blood Donors.Materials and Methods:This study was conducted in sixty volunteers and the method used to determine the secretor status was hemagglutination inhibition method. Their blood was used to detect the type of Lewis (Le) antigen since the type of Lewis antigen correlated with the secretor status of the individual.Results:Among the sixty subjects tested, forty fi ve of them were found to be secretors and fifteen of them were Non-secretors. The number of Lewis (a+b-) individuals were twelve, Lewis (a-b+) were thirty nine and Lewis (a-b-) were nine.Conclusion:The prevalence of secretors was 75% and non-secretors were 25% respectively. We found 65 % of the volunteers were found to be Le (a-b+) positive, 20% were Le (a+b-) and the remaining 15% were Le (a-b-) which correlated with the ABH antigen secretor status.Asian Journal of Medical Sciences Vol.7(5) 2016 93-96

Contrasting Patterns of Polymorphisms at the ABO-Secretor Gene (FUT2) and Plasma α(1,3)Fucosyltransferase Gene (FUT6) in Human Populations

The coding sequences (∼1 kb) of FUT2 [ABO-Secretor type α(1,2)fucosyltransferase] and of FUT6 [plasma α(1,3)fucosyltransferase] were analyzed for allelic polymorphism by direct sequencing in five populations. The nucleotide diversities of FUT2 estimated from pairwise sequence differences were 0.0045, 0.0042, 0.0042, 0.0009, and 0.0008 in Africans, European-Africans, Iranians, Chinese, and Japanese, respectively. The nucleotide diversities of FUT6 were 0.0024, 0.0016, 0.0015, 0.0017, and 0.0020 in Africans, European-Africans, Iranians, Chinese, and Japanese, respectively. At FUT2, excesses in pairwise sequence differences compared to the number of polymorphic sites as indicated by a significantly positive Tajima’s D were observed in European-Africans and in Iranians. The data do not fit expectations of the equilibrium neutral model with an infinite number of sites. On the other hand, Tajima’s D’s at FUT6 in each of the five populations and at FUT2 in Africans, Chinese, and Japanese were not significantly different from zero. FST between the Asians and the others measured at FUT2 was higher than at FUT6. These results suggest that natural selection was responsible for the generation of the FUT2 polymorphism in European-Africans and in Iranians.

Quantitative Estimates of ABH Secretion in Saliva of Human Twins

Blood and saliva samples of 122 like-sexed twin pairs (65 MZ and 57 DZ) living in Chandigarh (India) were analyzed for ABH polymorphism. The results indicated that ABH secretions were independent of ABO blood groups though there was an indication of higher incidence of non-secretors among ‘O’ blood group twin individuals. No significant differences were observed between twins and singletons in secretor gene frequency estimates. The quantitative data revealed that mean titre scores for H substances were lower than that for A and B substances. F test contrasting intra-pair variance between zygosities for ABH quantitative secretions was highly significant indicating stronger genetic component of variation. The results suggested that quantitative assay of ABH secretions would be a better indicator for zygosity determination than mere qualitative differentiation.