The congenital neutropenia (severe and cyclic type) is autosomal dominant, with mutations in the ELA2 gene (neutrophil elastase) as the most common genetic reason for this condition. Acquired neutropenia (immune-associated neutropenia) is due to anti-neutrophil antibodies that target neutrophil-specific antigens, ultimately altering neutrophil function. Furthermore, emerging research suggests neutropenia without an identifiable etiology (idiopathic neutropenia) may be the result of a  low-grade, chronic inflammatory process with an abnormal excessive production of myelosuppressive cytokines in a study conducted in the island of Crete.Neutropenia fever can complicate the treatment of cancers. Observations of children noted that fungal infections are more likely to develop in those with neutropenia. Mortality increases during cancer treatments if neutropenia is also present. Congenital neutropenia is determined by blood neutrophil counts (absolute neutrophil counts or ANC) < 0.5 × 109/L and recurrent bacterial infections beginning very early in childhood. Congenital neutropenia is related to alloimmunization, sepsis, maternal hypertension, twin-to-twin transfusion syndrome, and Rh hemolytic disease. Diagnosis
Neutropenia can be the result of a variety of consequences, including from certain types of drugs, environmental toxins, vitamin deficiencies, metabolic abnormalities, as well as cancer or infections. Neutropenia itself is a rare entity, but can be clinically common in oncology and immunocompromised individuals as a result of chemotherapy (drug-induced neutropenia). Additionally, acute neutropenia can be commonly seen from people recovering from a viral infection or in a post-viral state.
Acanthamoeba is a genus of amoebae that are commonly recovered from soil, fresh water, and other habitats. Acanthamoeba has two evolutive forms, the metabolically active trophozoite and a dormant, stress-resistant cyst. Trophozoites are small, usually 15 to 25 μm in length and amoeboid in shape. In nature, Acanthamoeba species are free-living bacterivores, but in certain situations, they can cause infections (acanthamebiasis) in humans and other animals. Distribution
Acanthamoeba spp. are among the most prevalent protozoa found in the environment. They are distributed worldwide, and have been isolated from soil, air, sewage, seawater, chlorinated swimming pools, domestic tap water, bottled water, dental treatment units, hospitals, air-conditioning units, and contact lens cases. Additionally, they have been isolated from human skin, nasal cavities, throats, and intestines, as well as plants and other mammals. Role in disease
Diseases caused by Acanthamoeba include keratitis and granulomatous amoebic encephalitis 
(GAE). The latter is often but not always seen in immunosuppressed patients. GAE is caused by the amoebae entering the body through an open wound and then spreading to the brain. The combination of host immune responses and secreted amoebal proteases causes massive brain swelling resulting in death in about 95% of those infected. Granulomatous amoebic encephalitis (GAE)
Granulomatous amoebic encephalitis (GAE) is caused by amoebic infection of the central nervous system (CNS). It is characterized by neurological symptoms including headache, seizures, and mental-status abnormalities. These worsen progressively over weeks to months, leading to death in most patients.