Molecular Genetic Analysis of the ABO Blood Group System: 4. Another Type of O Allele

Abstract

We have encountered an allele which seems to be another type of O allele at the human histo-blood group ABO locus. We have determined the nucleotide sequence of this allele over the coding region in the last two coding exons. This allele does not possess the single-nucleotide deletion found common among all the O alleles previously analyzed. Compared with A1 allele, this allele has three nucleotide substitutions resulting in two amino acid substitutions. The introduction of these amino acid substitutions into the A1 transferase expression construct apparently abolished the enzymatic activity of A1 transferase.

Genomic analysis of clinical samples with serologic ABO blood grouping discrepancies: identification of 15 novel A and B subgroup alleles

“…[7][8][9][10] Only one or 2 individuals with each phenotypic variant were investigated by sequencing of exons 6 and 7 in the ABO gene. Investigation of other subgroup alleles followed, [11][12][13][14][15] but several examples exist in which no deviation from the consensus sequence was found in exons 6 and 7.…”

Molecular genetic basis of porcine histo-blood group AO system

“…In rare cases in which O alleles were missing the single base deletion, an amino acid substitution was found at a residue crucial for nucleotide-sugar recognition and binding. 5 In addition to the 3 major alleles, we identified mutations in subgroup alleles and in cis AB and B(A) alleles that specify the synthesis of both A and B antigens. 1 The updated list of ABO alleles is available at the Blood Group Antigen Gene Mutation Database Web site (http://www.bioc.aecom.yu.edu/bgmut/index.htm).…”

Structural Basis for the Inactivity of Human Blood Group O2 Glycosyltransferase

“…More recently, an O 2 enzyme (O03) was discovered that was a full-length form of GTA with three substitutions, P74S, R176G, and G268R (7,8). The O 2 glycosyltransferase showed no measurable transferase activity when expressed in Sf9 cells (9).…”