 Chronic eosinophilic leukemia may transform into acute eosinophilic or other types of acute myelogenous leukemia.Familial eosinophilia is a rare congenital disorder characterized by the presence of sustained elevations in blood eosinophil levels that reach ranges diagnostic of eosinophilia or, far more commonly, hypereosinophilia.It is an autosomal dominant disorder in which genetic linkage gene mapping family studies localize the gene responsible for it to chromosome 5 at position q31-q33, between markers D5S642 and D5S816.