New and unusual O alleles at the ABO locus are implicated in unexpected blood group phenotypes |
| |
Authors: | Hosseini-Maaf Bahram Irshaid Nidal M Hellberg Asa Wagner Thomas Levene Cyril Hustinx Hein Steffensen Rudi Chester M Alan Olsson Martin L |
| |
Affiliation: | Blood Center, Lund University Hospital and Department of Transfusion Medicine, Institute of Laboratory Medicine, Lund University, Lund, Sweden. |
| |
Abstract: | BACKGROUND: In the ABO blood group system mutations in the A gene may lead to weak A subgroups owing to a dysfunctional 3-alpha-N-acetylgalactosaminyltransferase. STUDY DESIGN AND METHODS: Blood and DNA were investigated to correlate weak A phenotypes with genotype, and an overrepresentation of the infrequent O2 allele was observed. Consequently, 57 available O2 alleles were examined in detail. RESULTS: Two new O2 alleles were identified having mutations resulting in Gly229Asp with or without Arg217Cys. A recently described O2 variant (488C>T; Thr163Met) was also found. Surprisingly, both the original and the variant O2 alleles were associated with either O or Aweak phenotypes. Three novel O alleles surfaced in six other samples with suspected A subgroups. These were A1-like alleles having nonsense mutations causing premature truncation at codons 56, 107, or 181. A second example of the rare O3 allele was also identified. A newly described O1 allele having 768C>A was found to be the third most frequent O allele among Swedish donors. Of the five novel O alleles, three were incorrectly interpreted as A1 following routine ABO genotyping. CONCLUSION: Apparent O alleles lacking 261delG may cause weak A expression on red blood cells and/or inhibit anti-A production. A hypothesis that exchange of genetic material between principally dissimilar O alleles during mitosis ("autologous chimerism") restores glycosyltransferase activity in some cells would explain this interesting phenomenon. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|