Rh-hr Phenotype With ABO Grouping
Rh-hr Phenotype With ABO Grouping
    
Number
058008
CPT
86900; 86906
Related Information
  • ABO Grouping
  • ABO Grouping and Rho(D) Typing
    • Synonyms
    Rh Genotype ; Rh-hr Genotype
    Test Includes
    Tests for ABO blood grouping and the the Rh antigens D, C, E, c, and e (including test for “weak D”, if applicable)
    Specimen
    Whole blood
    Volume
    4 mL
    Minimum Volume
    1 mL
    Container
    Lavender-top (EDTA) tube
    Storage Instructions
    Specimens should be tested as soon as possible or within 72 hours of collection. Samples that cannot be tested immediately should be stored at 2°C to 8°C. Do not freeze red cells.
    Causes for Rejection
    Gross hemolysis; bacterial or other contamination
    Use
    Determine ABO blood grouping and most probable zygosity for D(Rho) antigen. Zygosity for C, E, c, and e antigens is also determined. Paternal typing may aid in the prediction of Rh hemolytic disease of the newborn.
    Limitations
    Abnormal plasma proteins, potent cold autoagglutinins, positive direct antiglobulin test, and in some cases bacteremia may interfere with test interpretation. Variable testing results may be observed with partial antigens which are rare variants of the Rho(D) antigen.
    Methodology
    Hemagglutination
    Additional Information
    When a woman of childbearing age has anti-D, it is important for prognostic purposes to determine the probability that her husband is homozygous or heterozygous for the gene determining the D antigen. If a prenatal patient is Rh-negative and the father of her fetus is homozygous for D, the child will always be Rh positive. Approximately 50% of the children of a heterozygous father will be Rh-negative. Testing to determine zygosity involves testing the subject's red blood cells for D, C, E, c, and e antigens. The results of this testing are referred to as the Rh phenotype. The Rh phenotype is used to determine a “most probable” zygosity for D based upon correlation of these results with a frequency chart detailing most probable Rh genotypes. In the case of D, this must be done indirectly since there is no detectable allele for this gene. In the case of the alleles C and c and the alleles E and e, the zygosity of these genes may be directly determined from the phenotyping results. Rh phenotyping of the father may also be helpful for evaluating the potential for hemolytic disease of the newborn in the presence of maternal antibodies to C, c, E, or e antigens. See table.
    Interpretation of Rh Phenotype Results
    in the Rh Positive Population


    Red Cell Antigen Typing Most Probable Genotype % Likelihood of Being Homozygous for D 
    D C E c e Caucasian Black Mestizo1 Whites Blacks Mestizos1 
    + + O + + CDe/cde CDe/cDe CDe/cde 10 59 15 
    + + O O + CDe/CDe CDe/CDe CDe/CDe 91 81 96 
    + O + + + cDE/cde cDE/cDe cDE/cde 10 63 15 
    + O + + O cDE/cDE cDE/cDE cDE/cDE 87 99 98 
    + + + + + CDe/cDE CDe/cDE CDe/cDE 89 90 97 
    + O O + + cDe/cde cDe/cde cDe/cde 6 46 8 
    For further information, please contact LabCorp or consult the source for this chart. 
    From Technical Manual, 15th ed, Bethesda, MD: American Association of Blood Banks, 2005. 
    1Mestizo frequencies were derived from a study of Mexican and Mexican-American population studies. The term “Mestizo” is commonly used in Hispanic countries to describe persons of mixed European and American Indian ancestry. 
    From Means ND, Bandarenko N, Moise KJ, et al, “Likelihood of D Heterozygosity in Mestizo Mexicans and Mexican-Americans,” Immunohematology, 2001, 17:22-3. 
    References

    Technical Manual, 15th ed, Bethesda, MD: American Association of Blood Banks, 2005.


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