CD Markers
CD240 D

Topic Completed: 1 August 2013

Minor changes: 4 December 2019

Copyright: (c) 2003-2019,, Inc.

PubMed Search: Rh blood group D

Related topics: CD240 CE, CD240 DCE

Nat Pernick, M.D.
Page views in 2019: 53
Page views in 2020 to date: 71
Cite this page: Pernick N. CD240 D. website. Accessed August 13th, 2020.
Definition / general
  • Also called RH30 D, Rh blood group D blood group antigen; is major antigen of the Rh system
  • On #1p36.11 adjacent to RHCE gene
  • Rh (rhesus) blood group system is second most clinically significant blood group after ABO; is most polymorphic blood group, with variations due to deletions, gene conversions, and missense mutations
  • Weak D, formerly called D(u), occurs in 0.2 to 1% of whites; exhibits reduced expression of D antigen (Blood 1999;93:385); should not be labeled as Rh negative (Curr Opin Hematol 2006;13:476)
  • Individuals are classified as Rh positive or negative based on presence or absence of highly immunogenic D antigen on red cell surface
  • May have arisen historically by duplication of RHCE gene (Blood 2002;99:2272)
  • Discrepant or doubtful serologic results can be resolved by PCR-SSP technique (Transfusion 2007;47:54S)
  • Hemolytic disease of fetus and newborn: usually due to Rh negative woman whose partner is Rh+ or heterozygous and fetus is Rh+; woman has preexisting anti-RhD antibodies that cross placenta and harm fetus (Immunohematol 2006;22:188)
  • Can use maternal plasma in alloimmunized pregnancies to determine fetal RhD status (Fetal Diagn Ther 2006;21:404), or for RHD and RHCE genotyping (Prenat Diagn 2005;25:1079); genotyping from amniotic fluid or chorionic villi sampling was performed in past, but is more invasive (N Engl J Med 1998;339:1734, Clin Exp Med 2002;2:77)
  • Rh positive mothers may rarely (0.15%) develop new antibodies (other than anti-RHD) in third trimester, but no clinical significance (J Matern Fetal Neonatal Med 2007;20:59)
  • Having Rh negative mother may be risk factor for autistic children, due to use of mercury containing Rho-immune globulin (J Matern Fetal Neonatal Med 2007;20:385)
Uses by pathologists
  • Blood typing
Positive staining - normal
  • Erythroid cells
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