Neutrophil count associated with the Duffy phenotype null

Abstract

Introduction. The Duffy-null phenotype is a variant of normal blood cell membrane antigens that causes the most frequent form of congenital neutropenia worldwide. Individuals who have it, mostly from sub-Saharan Africa, persistently have neutrophil counts below the normal range, without this implying an increased risk of infections.
Case report. We present a child, followed in our Neonatology Service, due to persistent neutropenia from birth, son of a mother from Equatorial Guinea. After several tests, the diagnosis of congenital neutropenia associated with Duffy null could be verified through peripheral blood immunophenotyping. The evolution of the child was satisfactory and he did not present any complications due to his neutropenia.
Conclusions. Duffy-Null Associated Congenital Neutropenia (DANC) should be classified as a genetic polymorphism that generates a variant of normality, adapting the ranges of neutrophil counts to it. There has been no increase in the risk of infections or autoimmune diseases, nor alterations in the function of neutrophils.  Considering these patients within the normal ranges of the majority of the population has consequences such as unnecessary tests, exclusion from clinical trials, or non-administration of oncological treatments.