RESUMO
CONCLUSIONS: This update of the H blood group system (Scharberg EA, Olsen C, Bugert P. The H blood group system. Immunohematology 2016;32:112-8) reports 11 new FUT1 null alleles: 8 causative for the H- phenotype (Bombay phenotype, Oh), 3 in para-Bombay cases, and 5 new FUT1 alleles causative for a weak H phenotype (para-Bombay, H+w). The H blood group system (International Society of Blood Transfusion system 18) consists of a single antigen (H) defined by a terminal fucose residue found on red blood cells (RBCs) and in secretions. The H antigen is synthesized on the RBC surface by the FUT1 gene product fucosyltransferase 1. On epithelial cells and in body fluids, the H antigen is synthesized by the FUT2 gene product fucosyltransferase 2.
Assuntos
Sistema ABO de Grupos Sanguíneos , Alelos , Fucose , Fucosiltransferases , Humanos , FenótipoRESUMO
The H blood group system, ISBT symbol H (018), consists of a single antigen (H) defined by a terminal fucose residue found on red blood cells and in secretions formed by the action of α-1,2-fucosyltransferases 1 (α2FucT1) and 2 (α2FucT2), respectively. Mutant alleles of the corresponding FUT1 and FUT2 genes result in either a H phenotype (Bombay phenotype, Oh) or a weak H phenotype (para-Bombay, H+w). In addition, the FUT2 gene is the molecular basis of the secretor (Se) status, and homozygosity or compound heterozygosity for null alleles is associated with the nonsecretor (se) status. H individuals have natural anti-H (mostly IgM), which can cause severe hemolytic transfusion reactions with intravascular hemolysis.
Assuntos
Sistema ABO de Grupos Sanguíneos , Antígenos de Bactérias/imunologia , Fucosiltransferases/genética , Sistema ABO de Grupos Sanguíneos/genética , Sistema ABO de Grupos Sanguíneos/imunologia , Alelos , Antígenos de Bactérias/biossíntese , Autoanticorpos/imunologia , Incompatibilidade de Grupos Sanguíneos , Sequência de Carboidratos , Cromossomos Humanos Par 19/genética , Eritrócitos/imunologia , Etnicidade/genética , Fucose/metabolismo , Estudos de Associação Genética , Glicosilação , Hemólise , Humanos , Imunoglobulina M/imunologia , Índia , Isoanticorpos/imunologia , Mutação , Processamento de Proteína Pós-Traducional , Reunião , Reação Transfusional , Galactosídeo 2-alfa-L-FucosiltransferaseRESUMO
BACKGROUND: STEM (RH49) is a low-prevalence antigen in the Rh blood group system. A scarcity of anti-STEM has precluded extensive study of this antigen. We report that two alleles with a RHCE*ce818C>T change encode a partial e, and a hr(S) -, hr(B) +, STEM+ phenotype and that both alleles are frequently in cis to RHD*DOL1 or RHD*DOL2. STUDY DESIGN AND METHODS: Blood samples were from donors and patients in our collections. Hemagglutination, DNA, and RNA testing was performed by standard techniques. RESULTS: Fourteen STEM+ samples were heterozygous RHCE*ce818C/T: six had RHCE*ceBI and eight had a novel allele, RHCE*ceSM. Eleven were heterozygous for RHD*DOL1 or RHD*DOL2. Eleven samples, previously typed STEM-, had RHCE*ce818C/C (consensus nucleotide). RBCs from informative STEM+ samples were e+/- hr(S) - hr(B) +. One person who was heterozygous RHCE*ceBI and RHCE*cE had an anti-e-like antibody in her plasma, and one person, who was hemizygous for RHD*DOL2, had anti-D in her plasma. CONCLUSIONS: We show that two alleles with a RHCE*ce818C>T change (RHCE*ceBI and RHCE*ceSM) encode a hr(S) - hr(B) + STEM+ phenotype. In addition, both alleles are frequently in cis to RHD*DOL1 or RHD*DOL2 and RHCE*ceBI encodes a partial e antigen. In the small cohort of samples tested, RHD*DOL invariably traveled with RHCE*ce818T. Our study also confirmed the presumption that RHD*DOL2, like RHD*DOL1, encodes a partial D antigen and the low-prevalence antigen DAK.
