Role of multiplex reverse-transcriptase PCR for diagnosis of Acute myelosis in an infant with Down's syndrome

Abstract

Children with Down syndrome (DS) are at a higher risk of developing Acute leukemias compared with the general pediatric population.1,2 Neonates with DS also may develop a transient myeloproliferative disorder (TMD), an abnormal proliferation of myeloid blasts in the blood that resolves without therapeutic intervention.3 TMD and acute myeloid leukemia (AML) in DS show strikingly similar morphologic features.1 The main difference in the clinical presentation of these disorders is the age of onset, with TMD occurring during the first few days of life and AML usually manifesting after 1 year.2 However, there may be diagnostic difficulty in some cases as there have been reports of TMD at later ages (second or third month of life), as well as cases of “congenital leukemia”.4 Hematologic and cytogenetic differences between these disorders also have been described. TMD tends to manifest with normal hematocrit and platelet counts, whereas AML generally exhibits cytopenias.1 Blasts in TMD usually have only the constitutional Trisomy 21, whereas blasts in AML may show additional complex cytogenetic abnormalities.5 One of the few modalities available to establish the diagnosis would be by identifying one of the 28 possible mutations associated with AL. We present a case report on the use of Multiplex RT-PCR in the diagnosis of Acute myelosis in Down's syndrome.6