Blood Group Antigen Gene Mutation Database

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Landsteiner-Wiener Blood Group System

Introduction

The protein carrying the antigens for the Landsteiner-Wiener blood group system is a product of a single gene, ICAM4 which consists of 3 exons distributed over 2.65 kb. The gene encodes a type I integral membrane glycoprotein of 241 residues in glycosylated form; its size, by Western blotting, is 42kD. The LW protein is a member of the Ig superfamily and bears similarity in sequence (30% identity) and structure to the intercellular adhesion molecules, ICAMs; in fact, LW, ICAM-1, and ICAM3 may have evolved by duplication from a common ancestral gene. Its binding to leukocyte-specific integrins parallels that of ICAMs.

Function of proteins

Plays a role in intercellular adhesion and is a ligand for integrins

Tissue distribution

Erythroid; not well documented in other tissues

Disease association

None known; however, LW antigens may be depressed during pregnancy and in some malignant states. Expression is elevated in sickle erythrocytes.

About the alleles

Two antithetical alleles, LWa and LWb and an allele resulting in a null phenotype have been documented so far. Regulation of expression of LW glycoprotein at the surface of the erythrocyte is not clear; it seems to be associated with the expression of Rh antigens. The molecular basis for the LW null phenotype was examined in only two subjects. In one subject no alteration in the LW gene was found.

In the list of alleles, sequence with accession number S78852 is taken as reference. The protein has a signal peptide of 30 residues that is not expressed at the membrane surface.

Other database IDs and links

Literature

New PubMed entries with the terms Landsteiner-Wiener and blood from the last 30 days.
NCBI Book Sections with the terms Landsteiner-Wiener and blood.

Contributors

Marion E. Reid and Christine Lomas-Francis, Immunohematology, New York Blood Center, 310 East 67 St, NY 10021

Contributors for specific alleles are listed with the alleles.

Links