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A novel blood group B subgroup: serological and genetic studies
Author(s) -
Estalote A. C.,
Palatnik M.,
Chester M. A.,
Olsson M. L.,
Sant'Anna Gomes B. M.
Publication year - 2004
Publication title -
transfusion medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.471
H-Index - 59
eISSN - 1365-3148
pISSN - 0958-7578
DOI - 10.1111/j.0958-7578.2004.00494.x
Subject(s) - abo blood group system , missense mutation , microbiology and biotechnology , biology , allele , phenotype , serology , genetics , chemistry , antibody , gene
summary A discrepancy in the ABO blood groups between a newborn child and her parents was identified. Serological and DNA investigative techniques were performed. A weak variant of B (B w ) was detected on the erythrocytes of the child, her grandmother and great‐uncle. Adsorption–elution studies showed that their erythrocytes adsorb and yield anti‐B on elution. The B w antigenic strength of the A 1 B w cells of her mother and maternal aunt was reduced when compared to that of the A 2 B w from another family member. Only one of 15 different anti‐B sera agglutinated the A 1 B w erythrocytes. Agglutinin anti‐B that reacted strongly with normal B erythrocytes and did not agglutinate the B w cells, was found in the sera of the A 1 B w individuals. The B w serum glycosyltransferase could not convert O cells into B cells and no B substance was found in saliva. All family members with the B w /AB w phenotypes were heterozygous for a B allele and DNA sequencing revealed a novel missense mutation in exon 7 of the B allele (556A > G), resulting in M186V. This substitution changes a highly conserved region of the enzyme, proposed to be a disordered loop near the enzyme cleft, and is expected to diminish the enzyme's activity, leading to this B w phenotype.