Molecular Analyses Of Gypb In African Brazilians

The molecular background of variant forms of GYPB is not well studied in Brazilians of African descent. The present study was carried out to determine the molecular bases of the S-s- phenotype and the frequency of GYPB*S silent gene for the S-s+ phenotype in a blood donor population of African Brazilians. In this study, 165 blood samples from African Brazilians (Northeastern Brazil) who phenotyped as S-s- (n = 17) and S-s+ (n = 148) by hemagglutination were selected. Allele-specific (AS)-PCR and PCR-restriction fragment length polymorphism (RFLP) were used to identify the variant forms of GYPB. In 13 of 17 S-s- samples (76.5%), both GYPB were deleted. In 137 of the 148 S-s+ samples (92.6%), the AS-PCR was consistent with the S-s+ phenotype. In 4 of the S-s- samples (23.5%) and 11 of the S-s+ samples (7.4%), the AS-PCR showed the presence of a GYPB*S allele associated with silencing of S. In the 4 donors with the S-s- phenotype, there was homozygosity (or hemizygosity) for the GYP(P2) allele (n = 2), homozygosity (or hemizygosity) for the GYP(NY) allele (n = 1), and heterozygosity for the GYP(P2) and GYP(NY) alleles (n = 1). In the 11 donors with the S-s+ phenotype, there was heterozygosity for GYP(P2) allele (n = S) and heterozygosity for GYP(NY) allele (n = 3). This study reports for the first time the molecular mechanisms responsible for the S-s- phenotype in a population of African Brazilians and provides new information about the frequency and molecular bases of the GYPB*S silent gene (7.4%) in this population.244148153Daniels, G.L., Fletcher, A., Garratty, G., Blood group terminology 2004: From the International Society of Blood Transfusion committee on terminology for red cell surface antigens (2004) Vox Sang, 87, pp. 304-316Reid, M.E., Lomas-Francis, C., (2004) Blood group antigen factsbook, , 2nd ed. San Diego: Academic PressBlumenfeld, O.O., Huang, C.-H., Molecular genetics of the glycophorin gene family. The antigens for MNSs blood groupsmultiple gene rearrangements and modulation of splice site usage result in extensive diversification (1995) Hum Mutat, 6, pp. 199-209Storry, J.R., Reid, M.E., Fetics, S., Huang, C.-H., Mutations in GYPB exon 5 drive the S-s-U+var phenotype in persons of African descent: Implications for transfusion (2003) Transfusion, 43, pp. 1738-1747Storry, J.R., Reid, M.E., MacLennan, S., Lubenko, A., Nortman, P., The low-incidence MNS antigens Mv, sD, and Mit arise from single amino acid substitutions on GPB (2001) Transfusion, 41, pp. 269-275Huang, C.-H., Johe, K., Moulds, J.J., Siebert, P.D., Fukuda, M., Blumenfeld, O.O., Glycophorin (Glycophorin B) gene deletion in two individuals homozygous for the S-s-U- blood group phenotype (1987) Blood, 70, pp. 1830-1835. , ¶Huang, C.-H., Reid, M.E., Blumenfeld, O.O., Remodeling of the transmembrane segment in human glycophorin by aberrant RNA splicing (1994) J Biol Chem, 269, pp. 10804-10812Huang, C.-H., Blumenfeld, O.O., Reid, M.E., Alternative splicing of a novel glycophorin allele GPHe(GL) generates two protein isoforms in the human erythrocyte membrane (1997) Blood, 90, pp. 391-397Reid, M.E., Storry, J.R., Ralph, H., Expression and quantitative variation of the low incidence blood group antigen He on some S-s- RBCs (1996) Transfusion, 36, pp. 719-724Rosse, W.F., Gallagher, D., Kinney, T.R., Transfusion and alloimmunization in sickle cell disease. The cooperative study of sickle cell disease (1990) Blood, 76, pp. 1431-1437Dhandsa, N., Williams, M., Joss, V., Patten, J., James, D., Sinclair, L., Haemolytic disease of the newborn caused by anti-U (1981) Lancet, 2, p. 1232Gottschall, J.L., Hemolytic disease of the newborn with anti-U (1981) Transfusion, 21, pp. 230-232Smith, G., Knott, P., Rissik, J., Win, N., Anti-U and haemolytic disease of the fetus and newborn (1998) Br J Obstet Gynaecol, 105, pp. 1318-1321Reid, M.E., Storry, J.R., Maurer, J., Nance, S.T., Practical method for determination of the U status of S-s- erythrocytes (1997) Immunohematology, 13, pp. 111-114Kan, Y.W., The William Allan Memorial Award Address: Thalassemia: molecular mechanism and detection (1986) Am J Hum Genet, 38, pp. 4-12Lowe, R.F., Moores, P., S-s-U- red cell factor in Africans of Rhodesia, Malawi, Mozambique and Natal (1972) Hum Hered, 22, pp. 344-350Habibi, B., Fouillade, M.T., Duedari, N., The antigen Duclos. A new high frequency red cell antigen to Rh and U (1978) Vox Sang, 34, pp. 302-309Dahr, W., Moulds, J.J., High-frequency antigens of human erythrocyte membrane sialoglycoproteins, IV. Molecular properties of the U antigen (1987) Biol Chem Hoppe-Seyler, 368, pp. 659-66