Would you expect a reduced neutrophil count in individuals with a partial duffy null phenotype?

The Duffy null phenotype's impact on neutrophil counts is "all or none". Approximately one-third of patients with the Duffy null phenotype Fy (a-b-) will have a neutrophil count below the usual lower limit of normal. The range of neutrophil counts in individuals with Fy (a+b-) and Fy (a-b+) is exactly the same as those with Fy(a+b+) phenotype. See Figure 1 from this free article on PubMed Merz et al., PMID 35994632.

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