Germline mutations among Polish patients with acute myeloid leukemia.

BACKGROUND: A small but important proportion of patients (4-10 %) with AML have germline mutations. They can cause the development of AML at an earlier age, confer a higher risk of relapse or predispose to secondary leukemias, including therapy-related leukemias. The analysis of germline mutations in a patient and his/her family is also critical for the selection of suitable family donors if the patient is a candidate for hematopoietic stem cell transplantation (HSCT). METHODS: 103 unrelated consecutive patients with de novo AML were enrolled in the study. Control group consisted of 103 persons from the general population. We performed NGS sequencing of bone marrow cells and buccal swabs DNA of six genes: CEBPA, DDX41, ETV6, TERT, GATA2, and IDH2 to detect germline pathogenic mutations. RESULTS: In the investigated group, 49 variants were detected in six genes. 26 of them were somatic and 23 germline. Germline variants were detected in all six tested genes. Eight pathogenic germline mutations were detected in 7 AML patients, in three genes: CEBPA, ETV6, and IDH2. One patient had two pathogenic germinal mutations, one in ETV6 and one in CEBPA gene. We identified one novel pathogenic germline mutation in CEBPA gene. The difference in frequency of all pathogenic germline mutations between the tested (7.77 %) and control groups (0.97 %) was statistically significant (p = 0.046). In the tested group, the median age at AML diagnosis was 11 years lower in patients with pathogenic germline mutations than in patients without them (p = 0.028). CONCLUSIONS: We showed higher frequency of CEBPA, ETV6, and IDH2 germline mutations in AML patients than in control group, which confirms the role of these mutations in the development of AML. We also showed that the median age at the onset of AML in patients with pathogenic germline mutations is significantly lower than in patients without them.

Searching for germline mutations in the RUNX1 gene among Polish patients with acute myeloid leukemia.

The aim of the study was the identification of constitutional RUNX1 mutations among AML patients. The study group included 100 patients of Polish origin, diagnosed with de novo AML. 14 out of 100 AML patients had together 17 RUNX1 mutations, three of which were found to be germline changes. The difference in germline mutation frequency between study and control groups was not statistically significant (p = 0.193), but the odds ratio was 7.215. In all patients with germline mutations, chromosome 7 aberrations were found. The difference in the frequency of chromosome 7 aberrations between the group of patients with and without germline mutations was statistically significant (p = 0.008, OR = 73.00). We showed a higher frequency of germline mutations of RUNX1 in AML patients than in the control group, which confirms the role of these mutations in the development of AML, and an association of germline mutations with aberrations of chromosome 7.

Advantages and Limitations of SNP Array in the Molecular Characterization of Pediatric T-Cell Acute Lymphoblastic Leukemia.

T-cell acute lymphoblastic leukemia (T-ALL) is a highly heterogeneous disease, and numerous genetic aberrations in the leukemic genome are responsible for the biological and clinical differences among particular ALL subtypes. However, there is limited knowledge regarding the association of whole-genome copy number abnormalities (CNAs) in childhood T-ALL with the course of leukemia and its outcome. The aim of this study was to identify the pattern of whole-genome CNAs in 86 newly diagnosed childhood T-ALL cases using a high-density single-nucleotide polymorphism array. We analyzed the presence of whole-genome CNAs with respect to immunophenotype, clinical features, and treatment outcomes. A total of 769 CNAs, including trisomies, duplications, deletions, and segmental loss of heterozygosity, were detected in 86 analyzed samples. Gain or loss of chromosomal regions exceeding 10 Mb occurred in 46 cases (53%), including six cases (7%) with complex chromosomal alterations. We observed that microdeletions in selected genes (e.g., FIP1L1 and PDGFRB) were related to the clinical features. Interestingly, 13% of samples have a duplication of the two loci (MYB and AIH1-6q23.3), which never occurred alone. Single-nucleotide polymorphism array significantly improved the molecular characterization of pediatric T-ALL. Further studies with larger cohorts of patients may contribute to the selection of prognostic CNAs in this group of patients.

Constitutional mutations of the CHEK2 gene are a risk factor for MDS, but not for de novo AML.

CHEK2 plays a key role in cellular response to DNA damage, and also in regulation of mitosis and maintenance of chromosomal stability. In patients newly diagnosed with myelodysplastic syndrome (MDS, n = 107) or acute myeloid leukemia (AML, n = 117) congenital CHEK2 mutations (c.444 + 1G > A, c.1100delC, del5395, p.I157 T) were tested by PCR and sequencing analysis. The karyotype of bone marrow cells of each patient was assessed at disease diagnosis using classical cytogenetic methods and fluorescence in situ hybridization. The CHEK2 mutations were strongly associated with the risk of MDS (p < 0.0001) but not with the risk of de novo AML (p = 0.798). In CHEK2-positive MDS patients, two times higher frequency of aberrant karyotypes than in CHEK2-negative patients was found (71% vs. 37%, p = 0.015). In CHEK2-positive patients with cytogenetic abnormalities, subtypes of MDS: refractory anemia with excess blasts-1 or 2, associated with unfavorable disease prognosis, were diagnosed two times more often than in CHEK2-negative cases with aberrations (78% vs. 44%). In conclusion, the congenital CHEK2 inactivation is strongly associated with the risk of MDS and with a poorer prognosis of the disease. However, the chromosomal instability in AML is not correlated with the hereditary dysfunction of CHEK2.

Concomitance of monosomal karyotype with at least 5 chromosomal abnormalities is associated with dismal treatment outcome of AML patients with complex karyotype - retrospective analysis of Polish Adult Leukemia Group (PALG).

Monosomal karyotype (MK) and complex karyotype (CK) are poor prognostic factors in acute myeloid leukemia (AML). A comprehensive analysis of cytogenetic and clinical factors influencing an outcome of AML-CK+ was performed. The impact of cladribine containing induction on treatment results was also evaluated. We analyzed 125 patients with AML-CK+ treated within PALG protocols. MK was found in 75 (60%) individuals. The overall complete remission (CR) rate of 66 intensively treated patients was 62% vs. 28% in CK+ MK- and CK+ MK+ group (p = .01). No difference in CR rate was observed between DA and DAC arms. The overall survival (OS) in intensively treated patients was negatively influenced by MK, karyotype complexity (≥5 abnormalities), and WBC >20 G/L in multivariate analysis. The addition of cladribine to DA regimen improved OS only in MK- but not in MK+ group. In conclusion, concomitance of MK with ≥5 chromosomal abnormalities is associated with dismal treatment outcome in AMK-CK+.

[The hematological malignancies related to primary hypereosinophilia and their diagnostics]. / Nowotwory ukladu krwiotwórczego przebiegajace z pierwotna hipereozynofilia i ich diagnostyka.

Published in 2008, by experts of the World Health Organization, the new classification of hematological malignancies forced a change of look at chromosomal aberrations and gene mutations, which are important in establishing the diagnosis and prognosis for patients with these malignancies. The new classification includes a new category of neoplasms - hematological malignancies with hypereosinophilia. Due to the high diversity of causes of hypereosinophilia and underlying genetic changes, their differential diagnosis is based on classical cytogenetics, fluorescence in situ hybridization (FISH) and genetic molecular techniques. Cytogenetic analysis of bone marrow cells showed that the majority of hypereosinophilia cases can be characterized by the presence of normal karyotype. Therefore, routine cytogenetic diagnostics should be complemented by FISH with break-apart probes for potentially rearranged genes (e.g., CBFB, ETV6) and unique probes for fusion genes (e.g., FIP1L1-PDGFRA), specific for hypereosinophilia-associated diseases. In differential diagnosis of hypereosinophilia, the analysis of characteristic gene mutations (e.g., cKIT) and gene fusions (e.g., ETV6-PDGFRB) is also applied, using molecular genetic methods.

Usefulness of classic cytogenetic testing compared to fluorescence in situ hybridization in genetic diagnosis of 58 patients with myelodysplastic syndromes.

INTRODUCTION: Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal diseases of pluripotent hematopoietic stem or progenitor cells. MDS are characterized by ineffective hematopoiesis, increased apoptosis, peripheral blood cytopenias, and propensity to evolve into acute myelogenous leukemia. OBJECTIVES: The aim of our investigation was to compare the usefulness of classic cytogenetics and fluorescence in situ hybridization (FISH) to detect chromosome aberrations in myelodysplastic syndromes. PATIENTS AND METHODS: The study was carried out in a group of 58 patients with MDS. G-banding using trypsin and Giemsa (GTG banding) and FISH with a panel of five molecular probes for aberrations with prognostic significance in MDS (cen7/8, 5q31, 7q22/q35, 17p13, 20q13.3) were performed on bone marrow cells. RESULTS: The use of GTG technique allowed to detect chromosome aberrations in 25 (43.1%) subjects. However, the additional use of FISH showed the presence of aberrations also in additional 10 (17.2%) patients, which shifted 11 patients from one cytogenetic category to another. CONCLUSIONS: The use of FISH with MDS probe panel beside classic cytogenetics improves detection of chromosome aberrations, and also stratification of MDS patients to prognostic groups. Both methods should be used simultaneously in every genetically diagnosed MDS patient.

[Microtia: isolated defect of hearing organ, or syndrome forming collection of abnormalities]. / Mikrocja--izolowane zaburzenie rozwojowe narzadu sluchu czy zespól wad?

Congenital malformations of the external ear are relatively rare, however gradual increase in their frequency has been observed in the last years. These defects can occur as isolated congenital malformations, but they can coexist with congenital malformations of facial skeleton and also with congenital defects of distant organs. The purpose of this study was to determine coexisting facial skeleton defects and congenital defects of distant organs in a group of patients with unilateral or bilateral congenital malformations of the external ear. 37 patients age 1 to 30 [mean age 12.4 years] with anotia, microtia or aplasia of external ear canal were part of this study. In 17 examined patients [46.0% of all examined persons] microtia could be treated as an isolated malformation, however hypoplasia of other elements formed from branchial arches, including mandibula, cheek or oral cavity, was found in 15 examined patients [40.5%]. In 11 [29.7%] patients congenital malformations of the external ear were found together with the congenital defects of distant organs (kidney, heart, muscular and skeletal system), and in two patients [5.4%] the defects involved even two different distant organs. Defects of the distant organs were found more frequently in patients with bilateral malformations of the external ear than in patients with unilateral ear malformation. In authors opinion each patient, even with seemingly isolated microtia, should be closely examined in order to exclude probable congenital defects of the distant organs.

The application of conventional cytogenetics, FISH, and RT-PCR to detect genetic changes in 70 children with ALL.

We investigated bone marrow cells of 70 acute lymphoblastic leukemia children by conventional cytogenetics (CC), fluorescence in situ hybridization (FISH), and reverse transcription polymerase chain reaction (RT-PCR) methods. CC and RT-PCR for fusion genes BCR/ABL, MLL/AF4, E2A/PBX1, TEL/AML1 were performed at diagnosis in each patient. FISH was performed to verify the presence of fusion genes and MLL rearrangements and to estimate the percentage of abnormal cells. Karyotypes were obtained in 59 (84%) of 70 cases. Thirty-five (59%) of 59 cases revealed chromosome aberrations. Hyperdiploidy>50 chromosomes was present in nine cases, hyperdiploidy 47-50 chromosomes in six, pseudodiploidy in 15, and hypodiploidy in five. BCR/ABL was present in two cases, PBX1/E2A in two, and TEL/AML1 in 14. MLL/AF4 was not found, but the rearrangements of MLL gene were present in five children. The addition of RT-PCR and FISH to CC was of the utmost importance. One of two Ph translocations and one of two t(1;19) were first revealed by RT-PCR. Moreover, FISH showed the percentage of TEL/AML1(+) cells that turned to be an important prognostic factor. The outcome was the best for the children with hyperdiploidy>50 chromosomes without structural changes. It was also good for those with TEL/AML1 present in >or=80% of cells without chromosome aberrations. The presence of pseudodiploidy correlated with poor outcome. The outcome for patients with t(9;22)-BCR/ABL or 11q23-MLL rearrangement was the worst in study group. The presence of BCR/ABL caused eight times increase of risk of death; MLL rearrangements caused 12 times increase.

[The results of cytogenetic and molecular genetic examinations in 35 couples with primary sterility]. / Wyniki badan cytogenetycznych i molekularnych u 35 par z nieplodnoscia pierwotna.

UNLABELLED: The causes of primary sterility are complex and frequently difficult to elucidate. Cytogenetic anomalies are responsible for sterility in 5-10% infertile couples. OBJECTIVES: Analysis of genetic background of primary sterility in 35 infertile couples. MATERIALS AND METHODS: 72h cultures of peripheral blood lymphocytes, GTG and CBG banding, fluorescence in situ hybrydization (FISH) with whole chromosome painting (WCP) probes. Karyotype analysis was performed in each patient out of 35 infertile couples referred to genetic counsel. SRY and CFTR gene mutation analysis by PCR was performed in all men with abnormal sperm. RESULTS: Chromosome aberrations were found in 6 couples. Klinefelter syndrome (47,XXY) was disclosed in 2 men. Isochromosome i(Xq) was found in 1 woman. The structural balanced translocations were found in 2 men; t(15;16)(q13;p13.3), t(1;19)(p35;q13.3) and a robertsonian translocation t(14;21)(q10;q10) in one. All men with chromosome aberrations had sperm anomalies: oligozoospermia, astenozoospermia, cryptozoospermia or azoospermia. There was a CFTR mutation, deltaF508, in one man and no SRY mutation in molecularly examined men with sperm abnormalities. CONCLUSIONS: In couples with primary sterility mainly the men are carriers of chromosome aberrations (CA). Because of 17.14% risk of the presence of chromosome aberrations in these couples, cytogenetic analysis should be an obligatory element of infertility diagnosis.