q) arm of chromosome 11; inversion of chromosome 16 occurring between p13.3 and q24.3 denoted as inv(16)(p13.3q24.3) that results in the production of a CBFA2T3-GLIS2 fusion protein; and increases in chromosome numbers from a normal of 46 to anywhere from 47 to >50. The relationships of these and the many other genetic abnormalities detected in non-Down-AMKL to the diseases development require further investigations. Presentation
Non-DS-AMKL occurs in neonates, infants, and children of all ages. Except for the lack of Down syndrome, no history of TMD, and occurrences in children that can be >4 years of age, individuals with non-DS-AMKL present with many of the symptoms, signs, and hematological findings seen in DS-AMKL. However, non-DS-AMKL is a more aggressive and rapidly progressing disorder than DS-AMKL. Nonetheless, the presentation of non-DS-AMKL is also like DS-AMKL in that it is not often accompanied by one or more extramedullary signs or symptoms of the disease such as liver enlargement, spleen enlargement, leukemia cutis, and leukostasis. Diagnosis
The diagnosis of non-DS-AMKL is made in children who do not have Down syndrome but exhibit the same clinical symptoms, signs, hematological abnormalities, and specialized laboratory findings seen in DS-AMKL. These children should bear one or more of the genetic aberrations associated with the disease but not the inactivating GATA1 mutations, extra copies of chromosome 21 genes, or other genetic abnormalities associated with DS-AMKL.
Immunochemical analyses, often conducted by flow cytometry, of the surface antigens on leukemic blast cells are positive for CD41, CD42b, CD51, and Von Willebrand factor in AMKL but not leukemia involving non-platelet malignant cells.Where indicated and available, the diagnosis of DS-AMKL is further supported by; immunophenotyping analysis using monoclonal antibody directed against megakaryocyte restricted antigen (CD41 and CD61) and DNA sequencing to detect GATA1  mutations that are projected to cause the gene to make GATA1-S but not GATA1 transcription factors. Treatment
The chemotherapy regimens used for all types of AMKL are similar to those used for AML. A final confirmation of safety and efficacy phase 3 study consisted of 4 cycles of induction therapy with cytarabine and daunorubicin followed by a single course of intensification therapy consisting of cytarabine and L-asparaginase, and concluded with a central nervous system consolidation course of 3 additional doses of intrathecal cytarabine. The dosages of cytarabine in this study were kept low because DS-AMKL patients proved highly susceptible to the toxic effects of the regimen which used a higher cytarabine dosage to treat AML. The low-dose cytarabine regimen achieved excellent results in DS-AMKL with relatively reduced overall toxicity and is currently recommended as a preferred treatment regimen for the disease.Autologous hematopoietic stem cell transplantation (i.e. transplantation of stem cells derived from the individual being transplanted) did not improve relapse-free survival in one large study of DS-AMKL. Allogenic hematopoietic stem cell transplantation (i.e.