• Rationale and Comments

    Individuals, typically of African or Middle Eastern ancestry, may present with an absolute neutrophil count (ANC) < 1,500 cells per μL with no signs of recurrent infections, immunocompromise, or malignancy. Frequently, the lower ANC is a normal variant associated with the red blood cell Duffy-null phenotype [Fy(a-b-)] that should be confirmed by blood bank phenotyping. Asymptomatic Duffy-null individuals do not require additional testing and should not be denied clinical trial participation or prescription of certain medications (including chemotherapy) based on ANC alone.

    Sponsoring Organizations

    • American Society for Clinical Laboratory Science
    • American Society for Clinical Pathology


    • Expert consensus


    • Hematologic


    • Merz LE, Achebe M. When non-whiteness becomes a condition. Blood. 2021 7;137(1):13-15.