Rearrangements of the red-cell membrane glycophorin C (sialoglycoprotein beta) gene. A further study of alterations in the glycophorin C gene.
We have cloned portions of the glycophorin C (sialoglycoprotein beta) gene from individuals with red cells of normal, Gerbich and Yus phenotypes. The clones contain up to three exons of the glycophorin C gene (designated exons 2, 3 and 4). Analysis by restriction mapping and DNA sequencing confirmed that the deletions causing the Gerbich and Yus phenotypes are located entirely within the glycophorin C gene. Sequencing of the normal gene showed that not only do exon 2 and exon 3 have related DNA sequences, but also that both the 5' and 3' flanking intronic DNA sequences are almost identical. The two variant genes each lack a different exon: the Yus type gene lacks exon 2, whereas the Gerbich-type gene lacks exon 3. We suggest that the observed deletions are due to recombination between the regions of homologous intronic repeats. We also provide evidence that an unequal cross-over mechanism may be responsible for a number of observed glycophorin C gene rearrangements, including an insertion mutation in Lewis II (Lsa)-type red cells that has not previously been reported.
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S
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Department of Biochemistry, University of Bristol, U.K.
Tanner
M J
MJ
Macdonald
E B
EB
Anstee
D J
DJ
D001483:Base Sequence; D004910:Erythrocyte Membrane; D005091:Exons; D015321:Gene Rearrangement; D014644:Genetic Variation; D006021:Glycophorins / Q000235:genetics*; D006801:Humans; D007983:Lewis Blood Group Antigens; D008969:Molecular Sequence Data; D010641:Phenotype; D015183:Restriction Mapping; D012795:Sialoglycoproteins / Q000235:genetics*
D006021:Glycophorins; D007983:Lewis Blood Group Antigens; D012795:Sialoglycoproteins