Website maintenance is planned from 8:00 a.m. CDT Saturday, July 27, through 9:00 p.m. CDT Sunday, July 28. Brief disruptions may occur during this time.
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.