Cyclic neutropenia (OMIM #162800) is an autosomal dominant or de novo autosomal disease caused by mutations on the ELANE (formerly known as ELA2) gene that encodes for neutrophil elastase. ELANE gene localization is 19p13.3.
Cyclic neutropenia was first mentioned by Reimann and DeBerardinis in the 1940s as they observed a cyclic phenomenon of increase and decrease in neutrophil counts within 18–21 days (Donadieu et al. 2017). In 1999, Horwitz and colleagues identified mutations in the neutrophil elastase gene (ELANE), which were also found in patients with severe congenital neutropenia 1 (SCN1, OMIM #202700). As the same mutation is observed in patients with cyclic neutropenia and permanent SCN and the cyclic aspect is rarely seen in clinical practice, some authors believe that there is a continuum between SCN and intermittent/cyclic neutropenia (Donadieu et al. 2017). Additionally, intermittent neutropenia...