No abstract available.
*Aneuploidy ; Bone Marrow/pathology ; Chromosomes, Human, Pair 21 ; Down Syndrome/*complications ; Female ; Humans ; Hyperplasia/pathology ; In Situ Hybridization, Fluorescence ; Infant ; Isochromosomes/*genetics ; Karyotype ; Leukemia, Megakaryoblastic, Acute/complications/*diagnosis ; Megakaryocytes/pathology

Although acquired mutations in the GATA1 gene have been reported for Down syndrome-related acute megakaryoblastic leukemia (DS-AMKL) in Caucasians, this is the first report of a Korean Down syndrome patient with AMKL carrying a novel mutation of the GATA1 gene. A 3-yr-old Korean girl with Down syndrome was admitted to our hospital complaining of pallor and fever. The findings of a peripheral blood smear and bone marrow study were compatible with the presence of AMKL. A chromosome study showed 48,XX,-7,+21c,+21,+r[3]/47,XX,+21c[17]. Following GATA1 gene mutation analysis, a novel mutation, c.145dupG (p.Ala49GlyfsX18), was identified in the N-terminal activation domain of the GATA1 gene. This mutation caused a premature termination at codon 67 and expression of an abnormal GATA-1 protein with a defective N-terminal activation domain, and the absence of full-length GATA-1 protein. This case demonstrates that a leukemogenic mechanism for DS-AMKL is contributed by a unique collaboration between overexpressed genes from trisomy 21 and an acquired GATA1 mutation previously seen in Caucasians and now in a Korean patient.
Base Sequence ; Child, Preschool ; Chromosomes, Human, Pair 21 ; Down Syndrome/complications/diagnosis/*genetics ; Female ; GATA1 Transcription Factor/*genetics ; Humans ; Karyotyping ; Korea ; Leukemia, Megakaryoblastic, Acute/diagnosis/etiology/*genetics ; *Mutation ; Phenotype ; Trisomy