<abstract xmlns="http://www.w3.org/1999/xhtml">The Colton (CO) blood group system consists of four antigens, Coa, Cob, Co3, and Co4, located on aquaporin-1 <italic>(AQP1),</italic>with Coahighly prevalent in all populations (99.8%). The Colton null phenotype, Co(a–b–), is very rare, and individuals with this phenotype lack the high-prevalence antigen Co3. To date, only six Co(a–b–) probands have been reported and four silencing alleles characterized. We identified an <italic>AQP1</italic>-null allele in a white woman with anti-Co3 caused by deletion of a G at nucleotide 601 (nt601delG) that results in a frameshift and premature termination (Val201Stop). Available family members were tested for the allele. Although anti-Co3 has been associated with mild to severe hemolytic disease of the fetus and newborn, the antibody was not clinically significant as evidenced by a low titer and delivery of asymptomatic newborns with moderate to weakly positive direct antiglobulin tests for all four pregnancies. <italic><bold>Immunohematology</bold></italic><bold>2013;29:1–4.</bold></abstract>

The Colton (CO) blood group system consists of four antigens, Coa, Cob, Co3, and Co4, located on aquaporin-1 (AQP1),with Coahighly prevalent in all populations (99.8%). The Colton null phenotype, Co(a–b–), is very rare, and individuals with this phenotype lack the high-prevalence antigen Co3. To date, only six Co(a–b–) probands have been reported and four silencing alleles characterized. We identified an AQP1-null allele in a white woman with anti-Co3 caused by deletion of a G at nucleotide 601 (nt601delG) that results in a frameshift and premature termination (Val201Stop). Available family members were tested for the allele. Although anti-Co3 has been associated with mild to severe hemolytic disease of the fetus and newborn, the antibody was not clinically significant as evidenced by a low titer and delivery of asymptomatic newborns with moderate to weakly positive direct antiglobulin tests for all four pregnancies. Immunohematology2013;29:1–4.

An <italic>AQP1</italic> allele associated with Co(a–b–) phenotype

Immunohematology

An  allele associated with Co(a–b–) phenotype

The Colton (CO) blood group system consists of four antigens, Coa, Cob, Co3, and Co4, located on aquaporin-1 (AQP1),with Coahighly prevalent in all populations...

An AQP1 allele associated with Co(a–b–) phenotype

Article Category: Case Report

Published Online: Dec 01, 2019

Page range: 1 - 4

DOI: https://doi.org/10.21307/immunohematology-2019-115

© 2013 S. Vege, et al., published by Sciendo