Neonatal Alloimmune Neutropenia is related to neutropenia and twinning, dizygotic. An important gene associated with Neonatal Alloimmune Neutropenia is FCGR3B (Fc Gamma Receptor IIIb). Affiliated tissues include neutrophil, and related phenotypes are neutropenia in presence of anti-neutropil antibodies and antineutrophil antibody positivity