BACKGROUND: fms-like tyrosine kinase (FLT3), a member of the class III receptor tyrosine kinases, regulates the proliferation and differentiation of hematopoietic stem cells. An internal tandem duplication of the FLT3 gene (FLT3/ITD) has been reported in acute myelogenous leukemia (AML) and may be associated with a poor prognosis. In this study we determined the prevalence and prognostic significance of FLT3/ITD in adult AML patients. METHODS: This study included 52 adult de novo AML. Exon 14 and 15 of the FLT3 gene were amplified by PCR and the PCR products were analyzed by 3730XL DNA analyzer (Applied Biosystems, USA) and GeneMapper Software. RESULTS: FLT3/ITD was found in 15 (28.8%) of the 52 AML patients. The presence of FLT3/ITD was significantly associated with absolute leukocyte counts (P=0.002) and bone marrow blast counts (P=0.036). FLT3/ITD was also more frequent in patients with normal karyotype (7 of 18) than in those with cytogenetic aberrations (3 of 25). Patients with t (15;17) showed a higher prevalence of FLT3/ITD (2 of 7). FLT3/ITD was significantly associated with overall survival (P<0.042). CONCLUSIONS: Our data indicate that FLT3/ITD is a common alteration in adult AML patients. Although based on a study with a limited number of AML patients, FLT3/ITD is a prognostic marker in patients with AML.
Adult ; Aged ; Aged, 80 and over ; Chromosomes, Human, Pair 15 ; Chromosomes, Human, Pair 17 ; Female ; Humans ; Leukemia, Myeloid, Acute/*genetics ; Male ; Middle Aged ; *Mutation ; Polymerase Chain Reaction ; Prognosis ; Survival Analysis ; Tandem Repeat Sequences/*genetics ; fms-Like Tyrosine Kinase 3/*genetics

FLT3 mutations are common genetic changes, and are reported to have prognostic significance in acute myeloid leukemia (AML). The FLT3 internal tandem duplication (ITD) and the D835 activating mutation in the tyrosine kinase domain (TKD) were analyzed by polymerase chain reaction (PCR) in the genomic DNA of Korean patients with AML at diagnosis and during follow-up. There were 226 patients with AML enrolled between March 1996 and August 2005. The incidence of ITD and TKD at diagnosis was 13% (29/226) and 3% (6/226). When compared to Western and other Asian patients with AML, Korean patients had a lower frequency by about two-thirds of ITD and TKD. Among the non-M3 cases (N=203), the patients with an ITD had a significantly shorter event-free survival when compared with those without an ITD (p=0.0079). Among 54 relapsed patients, 9 patients had the FLT3 ITD at diagnosis. Six patients demonstrated a reappearance of the ITD and 3 patients remained negative at relapse. One patient, among 45 patients who relapsed, had a negative baseline ITD but acquired a de novo ITD at relapse. There were 101 samples from 93 patients in remission; they were all negative for an ITD. Among 34 patients who failed to achieve a remission, five patients had a persistent ITD and one patient had a de novo ITD. These results support the concept of resistance of FLT3 ITD leukemic clones to chemotherapy. Therefore, effective therapy with FLT3 targeting agents may improve the prognosis of non-M3 AML patients with the FLT3 mutation.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; Disease-Free Survival ; Female ; *Gene Expression Regulation, Neoplastic ; Humans ; Infant ; Infant, Newborn ; Korea ; Leukemia, Myeloid, Acute/*genetics ; Male ; Middle Aged ; *Mutation ; Prognosis ; Recurrence ; Remission Induction ; fms-Like Tyrosine Kinase 3/*genetics

No abstract available.
Adolescent ; Child ; Flow Cytometry ; Gene Rearrangement ; Humans ; Immunophenotyping ; Karyotyping ; Male ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/*diagnosis ; Receptors, Antigen, T-Cell/genetics/metabolism ; fms-Like Tyrosine Kinase 3/genetics

BACKGROUND: The quality control for genetic tests would be of great importance as the test volume and clinical demands increase dramatically. Diagnostic genetics subcommittee of KSQACL performed two trials for cytogenetics and molecular genetics surveys in 2009. METHODS: A total of 67 laboratories participated in the cytogenetic surveys, 30 laboratories participated in the FISH surveys, and 94 laboratories participated in the molsecular genetics surveys in 2009. RESULTS: Almost of them showed acceptable results. However, some laboratories showed unacceptable results for the karyotype nomenclature and detection of complex cytogenetic abnormalities in hematologic neoplasms, and most of them except one showed acceptable results in FISH surveys. The molecular genetics surveys included various tests: M. tuberculosis detection, hepatitis B (HBV) and C virus (HCV) detection and quantification, human papilloma virus (HPV) genotyping, Influenza A (H1N1) detection, gene rearrangement tests for leukemias and lymphomas, apolipoprotein E (APOE) genotyping, methylenetetrahydrofolate reductase (MTHFR) genotyping, hereditary breast and ovarian cancer genes (BRCA1 and BRCA2), and genetic tests for achondroplasia (FGFR3), FMS-like tyrosine kinase 3 (FLT3), JAK2, BRAF, hereditary disorders such as spinal muscular atrophy, Huntington disease (HD), spinocerebellar ataxia (SCA), Prader-Willi/Angelman syndrome (PWS/AS), mitochondrial encephalopathy with lactic acidosis and strokelike episodes (MELAS), myoclonic epilepsy ragged red fiber (MERRF), wilson disease (ATP7B) and cancer-associated genes (KRAS). Molecular genetic surveys showed excellent results in most of the participants. CONCLUSIONS: External quality assessment program for genetic analysis in 2009 was proved to be helpful in continuous education and evaluation of quality improvement.
Achondroplasia ; Acidosis, Lactic ; Apolipoproteins ; Breast ; Chromosome Aberrations ; Cytogenetics ; Epilepsies, Myoclonic ; fms-Like Tyrosine Kinase 3 ; Gene Rearrangement ; Hematologic Neoplasms ; Hepatitis B ; Hepatolenticular Degeneration ; Humans ; Huntington Disease ; Influenza, Human ; Karyotype ; Korea ; Leukemia ; Lymphoma ; Methylenetetrahydrofolate Reductase (NADPH2) ; Mitochondrial Encephalomyopathies ; Molecular Biology ; Muscular Atrophy, Spinal ; Ovarian Neoplasms ; Papilloma ; Quality Control ; Quality Improvement ; Spinocerebellar Ataxias ; Tuberculosis ; Viruses

No abstract available.
Aged ; Base Sequence ; Bone Marrow/metabolism/pathology ; DNA Mutational Analysis ; Female ; Fusion Proteins, bcr-abl/*genetics ; Gene Duplication ; Humans ; In Situ Hybridization, Fluorescence ; Leukemia, Myeloid, Acute/diagnosis/*genetics ; Multiplex Polymerase Chain Reaction ; Mutation ; Nuclear Proteins/*genetics ; Philadelphia Chromosome ; fms-Like Tyrosine Kinase 3/*genetics

BACKGROUND: Nucleophosmin gene (NPM1) mutation may be a good molecular marker for assessing the clinical status and predicting the outcomes in AML patients. We evaluated the applicability of NPM1 type A mutation (NPM1-mutA) quantitation for this purpose. METHODS: Twenty-seven AML patients with normal karyotype but bearing the mutated NPM1 were enrolled in the study, and real-time quantitative PCR of NPM1-mutA was performed on 93 bone marrow (BM) samples (27 samples at diagnosis and 56 at follow-up). The NPM1-mutA allele burdens (represented as the NPM1-mutA/Abelson gene (ABL) ratio) at diagnosis and at follow-up were compared. RESULTS: The median NPM1-mutA/ABL ratio was 1.3287 at diagnosis and 0.092 at 28 days after chemotherapy, corresponding to a median log10 reduction of 1.7061. Significant correlations were observed between BM blast counts and NPM1-mutA quantitation results measured at diagnosis (γ=0.5885, P=0.0012) and after chemotherapy (γ=0.5106, P=0.0065). Total 16 patients achieved morphologic complete remission at 28 days after chemotherapy, and 14 (87.5%) patients showed a >3 log10 reduction of the NPM1-mutA/ABL ratio. The NPM1-mutA allele was detected in each of five patients who had relapsed, giving a median increase of 0.91-fold of the NPM1-mutA/ABL ratio at relapse over that at diagnosis. CONCLUSIONS: The NPM1-mutA quantitation results corresponded to BM assessment results with high stability at relapse, and could predict patient outcomes. Quantitation of the NPM1-mutA burden at follow-up would be useful in the management of AML patients harboring this gene mutation.
Antineoplastic Agents/therapeutic use ; Bone Marrow/metabolism/pathology ; Cytarabine/therapeutic use ; Daunorubicin ; Humans ; Karyotype ; Leukemia, Myeloid, Acute/drug therapy/genetics/*pathology ; Mutation ; Nuclear Proteins/*genetics/metabolism ; Real-Time Polymerase Chain Reaction ; Recurrence ; Remission Induction ; Retrospective Studies ; Sequence Analysis, DNA ; fms-Like Tyrosine Kinase 3/genetics