Paraoxonase 1 (PON1) Q192R and L55M Polymorphisms as Potential Predisposition Factors for Chronic Lymphocytic Leukemia.

Background/aim: PON1 gene has an executive role in antioxidant defense, protecting cells from genotoxic factors. Q192R and L55M PON1 polymorphisms reduce catalytic activity of the encoded protein. These polymorphisms were studied in 300 chronic lymphocytic leukemia (CLL) patients and 106 healthy donors.

ASXL1 mutations in AML are associated with specific clinical and cytogenetic characteristics.

Mutations of ASXL1 are early events in acute myeloid leukemia (AML) leukemogenesis and have been associated with unfavorable prognosis. In this study, we investigated the type and frequency of ASXL1 mutations in a large cohort of patients with de novo or secondary AML (s-AML) and looked for correlations with cytogenetic findings and disease features. ASXL1 mutations were associated with older age, s-AML and higher peripheral leukocytosis.

Possible Implication of GSTP1 and NQO1 Polymorphisms on Natalizumab Response in Multiple Sclerosis.

Oxidative stress plays a pivotal role in the pathogenesis of multiple sclerosis (MS). Inactivating polymorphism of genes encoding detoxification enzymes, such as NQO1 and GSTP1 could influence susceptibility to MS. The monoclonal antibody natalizumab is an effective treatment in MS.

Polymorphisms and haplotypes of the CYP2B6 detoxification gene in the predisposition of Acute Myeloid Leukemia (AML) and induction of its cytogenetic abnormalities.

CYP2B6 is a polymorphic detoxification gene which plays a vital role in the degradation of genotoxic compounds. In this study we hypothesized that inadequate detoxification due to CYP2B6 polymorphisms may contribute to AML. To evaluate the potential impact of CYP2B6 polymorphisms on AML development and induction of its specific chromosomal abnormalities we studied CA and AG polymorphisms for the first time in AML.

Association of C609T-Inborn Polymorphism of NAD(P)H: Quinone Oxidoreductase 1 with the Risk of Bronchopulmonary Dysplasia in Preterm Neonates.

Unlabelled: Objectives In bronchopulmonary dysplasia (BPD), direct exposure to oxygen therapy can damage the pulmonary epithelium via oxidative stress. The

Nad(p)h: quinone oxidoreductase 1 (NQO1) enzyme detoxifies genotoxic products of oxidative stress. The corresponding gene is subject to an inactivating single-nucleotide polymorphism (C(609)T), which reduces detoxifying ability.

Combined GSTP1 and NQO1 germline polymorphisms in the susceptibility to Multiple Sclerosis.

Unlabelled: Germline polymorphisms of detoxification genes could influence susceptibility to Multiple Sclerosis (MS). Glutathione-S-transferases (GSTs) and

Nad(p)h: quinone oxidoreductase 1 (NQO1) are detoxifying enzymes involved in biotransformation of metabolites preventing cells from oxidative damage. In order to evaluate the possible contribution of the A313G GSTP1 inactivating polymorphism, alone and in combination with the C609T NQO1 genetic variant in MS susceptibility, we performed a case-control study consisting of 254 MS patients and 370 healthy donors.

The G⁵¹⁶T CYP2B6 germline polymorphism affects the risk of acute myeloid leukemia and is associated with specific chromosomal abnormalities.

The etiology of acute myeloid leukemia (AML) underlies the influence of genetic variants in candidate genes. The CYP2B6 enzyme detoxifies many genotoxic xenobiotics, protecting cells from oxidative damage. The CYP2B6 gene is subjected to a single-nucleotide polymorphism (G⁵¹⁶T) with heterozygotes (GT) and homozygotes (TT) presenting decreased enzymatic activity.

High frequency of NAD(P)H:quinone oxidoreductase 1 (NQO1) C(609)T germline polymorphism in MDS/AML with trisomy 8.

The NQO1 C(609)T germline polymorphism resulting in a lowering of enzyme activity may confer susceptibility to MDS. To assess this association, we performed a case-control study including 330 Greek patients with de novo MDS and 416 healthy donors, using a Real-Time PCR genotyping method. Focusing on cytogenetic aberrations most commonly found in MDS, we retrospectively genotyped 566 MDS/AML patients carrying -5/del(5q), -7/del(7q), +8, del(20q) and -Y.

Cytogenetic abnormalities and monosomal karyotypes in children and adolescents with acute myeloid leukemia: correlations with clinical characteristics and outcome.

The whole spectrum of chromosomal abnormalities and their prognostic significance in children and adolescents with acute myeloid leukemia (AML) has not been fully elucidated yet, although a considerable amount of knowledge has been gained recently. Moreover, the incidence and prognostic impact of monosomal karyotypes (MKs), which are new cytogenetic categories reported recently in adults with AML, are currently unknown for childhood and adolescent AML. In this study, we investigated the cytogenetic and clinical characteristics of 140 children and adolescents (≤21 y) with AML, and correlated their cytogenetic features with both the clinical characteristics and outcomes of our patient cohort.

Association of A(313)G glutathione S-transferase P1 germline polymorphism with susceptibility to de novo myelodysplastic syndrome.

Models for the pathogenesis of myelodysplastic syndrome (MDS) imply the role of individual genetic variations in genes involved in detoxification mechanisms. GSTP1 enzyme plays a key role in the biotransformation of a variety of carcinogens. The corresponding gene is subject to a single nucleotide polymorphism (A(313)G) leading to abolished enzyme activity.

The C609T inborn polymorphism in NAD(P)H:quinone oxidoreductase 1 is associated with susceptibility to multiple sclerosis and affects the risk of development of the primary progressive form of the disease.

Oxidative stress plays a pivotal role in the pathogenesis of multiple sclerosis (MS). Inactivating polymorphisms of genes encoding detoxification enzymes, such as NAD(P)H:quinone oxidoreductase 1 (NQO1), could influence susceptibility to MS. To test this hypothesis we performed a case-control study in which we compared the distribution of NQO1 genotypes between 231 MS patients and 380 controls, using both PCR-RFLP and real-time PCR assays.

NPM1 deletion is associated with gross chromosomal rearrangements in leukemia.

Background: NPM1 gene at chromosome 5q35 is involved in recurrent translocations in leukemia and lymphoma. It also undergoes mutations in 60% of adult acute myeloid leukemia (AML) cases with normal karyotype. The incidence and significance of NPM1 deletion in human leukemia have not been elucidated.

Isochromosome der(17)(q10)t(15;17) in acute promyelocytic leukemia resulting in an additional copy of the RARA-PML fusion gene: report of 4 cases and review of the literature.

Isochromosome of the long arm of the derivative chromosome 17, originating from the translocation t(15;17) [ider(17)(q10)t(15;17) or ider(17q)] in acute promyelocytic leukemia (APL), is a rare chromosome aberration which has been associated with a poor prognosis. In the present study, we report on 4 male APL patients with ider(17q) and review the clinical, cytogenetic and molecular characteristics of all previously reported APL patients with ider(17q) in order to clarify the clinical features and outcome of these patients. The data presented in this study demonstrated that ider(17q), which resulted in an extra RARA-PML fusion gene, was more frequent in males than females (male/female ratio of 2.

Effect of lenalidomide therapy on hematopoiesis of patients with myelodysplastic syndrome associated with chromosome 5q deletion.

Background: Lenalidomide improves erythropoiesis in patients with low/intermediate-1 risk myelodysplastic syndrome and interstitial deletion of the long arm of chromosome 5 [del(5q)]. The aim of this study was to explore the effect of lenalidomide treatment on the reserves and functional characteristics of bone marrow hematopoietic progenitor/precursor cells, bone marrow stromal cells and peripheral blood lymphocytes in patients with low/intermediate-1 risk myelodysplastic syndrome with del(5q).

Design And Methods: We evaluated the number and clonogenic potential of bone marrow erythroid/myeloid/megakaryocytic progenitor cells using clonogenic assays, the apoptotic characteristics and adhesion molecule expression of CD34(+) cells by flow cytometry, the hematopoiesis-supporting capacity of bone marrow stromal cells using long-term bone marrow cultures and the number and activation status of peripheral blood lymphocytes in ten patients with low/intermediate-1 risk myelodysplastic syndrome with del(5q) receiving lenalidomide.

Jumping translocations in hematological malignancies: a cytogenetic study of five cases.

Jumping translocations (JT) are rare cytogenetic aberrations in hematological malignancies that include unbalanced translocations involving a donor chromosome arm or chromosome segment that has fused to two or more different recipient chromosomes in different cell lines. We report five cases associated with different hematologic disorders and JT to contribute to the investigation of the origin, pathogenesis, and clinical significance of JT. These cases involve JT of 1q in a case of acute myeloblastic leukemia (AML)-M1, a case of Burkitt lymphoma, and a case of BCR/ABL-positive acute lymphoblastic leukemia, as well as a JT of 13q in a case of AML-M5, and a JT of 11q segment in a case of undifferentiated leukemia.

Totipotent stem cells bearing del(20q) maintain multipotential differentiation in Shwachman Diamond syndrome.

SBDS/7q11 gene mutations underlie the congenital Shwachman Diamond syndrome (SDS), characterized by bone marrow failure and high risk of haematological malignancies. In two cases of SDS with bone marrow failure and isolated del(20q) interphase fluorescence in situ hybridization (I-FISH) found no abnormalities in FHIT/3p14.2, IKZF1/7p13, D7S486/7q31, PTEN/10q23.

5'RARA submicroscopic deletion from new variant translocation involving chromosomes 15, 17, and 18, in a case of acute promyelocytic leukemia.

Submicroscopic deletions of the PML-RARA fusion genes constitute rare rearrangements in acute promyelocytic leukemia (APL). We describe a rare case of APL carrying a novel complex translocation involving chromosomes 15, 17, and 18 associated with a submicroscopic deletion of the 5' part of the RARA gene, as evidenced by fluorescence in situ hybridization (FISH). A PML/RARA dual-fusion probe did not reveal the RARA-PML fusion signal on the der(17q), usually detected in the typical t(15;17).

Disruption of the ETV6 gene as a consequence of a rare translocation (12;12)(p13;q13) in treatment-induced acute myeloid leukemia after breast cancer.

We describe a case of treatment-induced acute myeloid leukemia M2 after breast cancer with a rare reciprocal t(12;12)(p13;q13) as a secondary cytogenetic abnormality in addition to the t(11;19)(q23;p13.1). Fluorescence in situ hybridization analysis revealed that both ETV6 genes (previously TEL) were located on the same der(12)t(12;12) as a result of t(12;12).

Leukemias associated with Turner syndrome: report of three cases and review of the literature.

Cases of leukemia associated with Turner syndrome (TS) are rare. Here we report three TS patients with leukemia including one case of T-large granular lymphocyte leukemia (T-LGL), one rare case of coexistence of chronic lymphocytic leukemia (CLL) and idiopathic myelofibrosis (IMF) and one case of a patient with AML-M2 who received autologous stem cell transplantation (SCT). T-LGL and coexistence of CLL and IMF associated with TS are reported for the first time while the last case represents the first report of SCT in a leukemia patient with TS.

Translocation (X;12)(p11;p13) as a sole abnormality in biphenotypic acute leukemia.

A reciprocal t(X;12)(p11;p13) was found as the sole clonal abnormality in biphenotypic leukemia with myeloid and B-lymphoid differentiation. With fluorescence in situ hybridization analysis, the ETV6 gene (previously TEL) was found to be translocated intact to the derivative X chromosome; no MLL and BCR/ABL rearrangements were found. The patient achieved complete remission after induction chemotherapy.

Switch in X-inactivation in a JAK2 V617F-negative case of polycythemia vera with two acquired X-autosome translocations.

We report a JAK2 V617F-negative case of polycythemia vera with two acquired balanced X-autosome translocations and no history of previous exposure to chemo/radiotherapy. The patient's first clone carried a novel translocation t(X;15)(q24;q13) as a sole abnormality. The second clone exhibited an additional translocation, t(X;20)(q13;q13.