Coexistence of sickle cell disease and severe congenital neutropenia: first impressions can be deceiving.

We report an Omani family in whom the propositus had a rare coexistence of sickle cell disease and severe congenital neutropenia associated with a mutation in ELANE. In contrast to his siblings with sickle cell disease, the severity of HbSS-associated complications such as painful crises and acute chest syndrome was significantly reduced. His course of the disease had markedly worsened after initiating G-CSF therapy. These clinical observations suggest that neutropenia may ameliorate inflammatory responses and thus display a modulating factor with respect to the clinical course of sickle cell disease.