The karyotype of bone-marrow cells at the time of diagnosis is one of the most important prognostic factors in patients with myelodysplastic syndromes (MDS). In some cases, the acquisition of additional genetic aberrations (clonal evolution [CE]) associated with clinical progression may occur during the disease. We analyzed a cohort of 469 MDS patients using a combination of molecular cytogenomic methods to identify cryptic aberrations and to assess their potential role in CE. We confirmed CE in 36 (8%) patients. The analysis of bone-marrow samples with a combination of cytogenomic methods at diagnosis and after CE identified 214 chromosomal aberrations. The early genetic changes in the diagnostic samples were frequently MDS specific (17 MDS-specific/57 early changes). Most progression-related aberrations identified after CE were not MDS specific (131 non-MDS-specific/155 progression-related changes). Copy number neutral loss of heterozygosity (CN-LOH) was detected in 19% of patients. MDS-specific CN-LOH (4q, 17p) was identified in three patients, and probably pathogenic homozygous mutations were found in TET2 (4q24) and TP53 (17p13.1) genes. We observed a statistically significant difference in overall survival (OS) between the groups of patients divided according to their diagnostic cytogenomic findings, with worse OS in the group with complex karyotypes (P = .021). A combination of cytogenomic methods allowed us to detect many cryptic genomic changes and identify genes and genomic regions that may represent therapeutic targets in patients with progressive MDS.
- MeSH
- analýza přežití MeSH
- chromozomální aberace MeSH
- DNA vazebné proteiny genetika MeSH
- dospělí MeSH
- klonální evoluce * MeSH
- lidé středního věku MeSH
- lidé MeSH
- mutace MeSH
- myelodysplastické syndromy klasifikace genetika patologie MeSH
- nádorový supresorový protein p53 genetika MeSH
- prognóza MeSH
- protoonkogenní proteiny genetika MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ztráta heterozygozity MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Deletion 20q is a recurrent abnormality in myeloid malignancies. In our previous study, we identified fusion of the additional sex combs-like 1 (ASXL1) and teashirt zinc finger homeobox 2 genes in a patient with myelodysplastic syndrome. The objective of this study was to determine the frequency of ASXL1 breakpoints in a cohort of 36 patients with deletion 20q as the sole cytogenetic aberration. A combination of molecular cytogenetic methods was used to confirm ASXL1 gene alterations in 19 of the 36 patients, and the determination of ASXL1 gene changes in patients with deletion 20q revealed clinical and prognostic impacts.
- Publikační typ
- abstrakt z konference MeSH
- Publikační typ
- abstrakt z konference MeSH
Dicentric chromosomes (DCs) are considered markers of cancer in various malignancies. However, they can be overlooked when conventional analysis or multicolor fluorescence in situ hybridization (mFISH) is used to detect complex karyotypes. We analyzed the karyotypes of 114 patients with acute myeloid leukemia (AML) and complex karyotypes and verified the presence of monosomies by FISH using multi-centromeric probes. Monosomy was detected in 63% of patients by G-banding/mFISH and confirmed in 55% of patients by centromeric FISH. FISH analysis indicated a high frequency of DCs that were previously considered monosomies. In some cases, it was apparent that the derivative monocentric chromosome was a primary DC. DCs were formed mostly by chromosomes 17 and 20. In conclusion, chromosome loss and unbalanced translocation suggest the presence of a hidden DC or its previous existence. DCs undergo several stabilizing changes and can induce other chromosomal aberrations and/or the formation of new DCs. This can result in the clonal evolution of abnormal cells, which is considered an independent prognostic marker of an unfavorable disease course and short survival.
- MeSH
- akutní myeloidní leukemie genetika MeSH
- analýza přežití MeSH
- centromera * MeSH
- chromozomální aberace * MeSH
- hybridizace in situ fluorescenční metody MeSH
- karyotyp * MeSH
- lidé středního věku MeSH
- lidé MeSH
- lidské chromozomy, pár 17 MeSH
- lidské chromozomy, pár 20 MeSH
- monozomie MeSH
- prognóza MeSH
- pruhování chromozomů MeSH
- senioři MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Constitutional translocations between sex chromosomes are rather rare in humans with breakpoints at Xp11 and Yq11 as the most frequent. Breakpoints on the short arm of the Y chromosome form one subgroup of t(X;Y), giving rise to a derived chromosome with the centromeres of both the X and Y chromosomes, dic(X;Y). Here, we report a rare congenital chromosomal aberration, 46,X,dic(X;Y)(p22.33;p11.32)[20]/45,X[10], in an adult male. CASE PRESENTATION: Primary myelofibrosis, a malignant haematological disease, was diagnosed in a 63-year-old man following liver transplantation after hepatocellular carcinoma. By the analysis of the bone marrow sample, the karyotype 46,X,dic(X;Y)(p22.33;p11.32) was detected in all the mitoses analysed and verified with multicolour fluorescence in situ hybridization (mFISH). A cytogenetic examination of stimulated peripheral blood cells revealed the constitutional karyotype 46,X,dic(X;Y)(p22.33;p11.32)[20]/45,X[10]. The cell line 45,X was confirmed with FISH in 35 % of interphase nuclei. The SRY locus was present on the dicentric chromosome. A CGH/SNP array (Illumina) revealed a gain of 153,7 Mbp of the X chromosome and a 803-kbp microdeletion (including the SHOX gene), which were also confirmed with FISH. SHOX encodes a transcriptional factor that regulates the growth of the long bones. The deletion of the SHOX gene together with the Madelung deformity of the forearm and the short stature of the proband led to a diagnosis of Léri-Weill dyschondrosteosis (LWD). The gain of almost the whole X chromosome (153,7 Mbp) was considered a variant of Klinefelter syndrome (KS). The levels of gonadotropins and testosterone were consistent with gonadal dysfunction. A malformation of the right external ear was detected. CONCLUSIONS: We have reported a structural aberration of the sex chromosomes, dic(X;Y)(p22.33;p11.32). The related genomic imbalance is associated with two known hereditary syndromes, LWD and a KS variant, identified in our proband at an advanced age. Because the breakpoints did not involve cancer genes, we inferred that the two malignancies in the proband were not caused by this abnormality. The possible influence of SHOX haploinsufficiency on the growth regulation of auricular chondrocytes is discussed.
- Publikační typ
- časopisecké články MeSH
Complex karyotypes are seen in approximately 20% of patients with myelodysplastic syndromes (MDS) and are associated with a high risk of transformation to acute myeloid leukemia and poor outcomes in patients. Copy number neutral loss of heterozygosity (CN-LOH, i.e., both copies of a chromosomal pair or their parts originate from one parent) might contribute to increased genomic instability in the bone-marrow cells of patients with MDS. The pathological potential of CN-LOH, which arises as a clonal aberration in a proportion of somatic cells, consists of tumor suppressor gene and oncogene homozygous mutations. The aim of our study was to evaluate the frequency of CN-LOH at 17p in bone-marrow cells of newly diagnosed MDS patients with complex chromosomal aberrations and to assess its correlation with mutations in the TP53 gene (17p13.1). CN-LOH was detected in 40 chromosomal regions in 21 (29%) of 72 patients analyzed. The changes in 27 of the 40 regions identified were sporadic. The most common finding was CN-LOH of the short arm of chromosome 17, which was detected in 13 (18%) of 72 patients. A mutational analysis confirmed the homozygous mutation of TP53 in all CN-LOH 17p patients, among which two frameshift mutations are not registered in the International Agency for Research on Cancer TP53 Database. CN-LOH 17p correlated with aggressive disease (median overall survival 4 months) and was strongly associated with a complex karyotype in the cohort studied, which might cause rapid disease progression in high-risk MDS. No other CN-LOH region previously recorded in MDS or AML patients (1p, 4q, 7q, 11q, 13q, 19q, 21q) was detected in our cohort of patients with complex karyotype examined at the diagnosis of MDS. The LOH region appeared to be balanced (i.e., with no DNA copy number change) when examined with conventional and molecular cytogenetic methods. Therefore, a microarray that detects single-nucleotide polymorphisms is an ideal method with which to identify and further characterize CN-LOH. Our data should specify the prognosis and should lead to the identification of potential targets for therapeutic interventions.
- MeSH
- chromozomální aberace * MeSH
- dospělí MeSH
- genová dávka * MeSH
- hybridizace in situ fluorescenční MeSH
- jednonukleotidový polymorfismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- lidské chromozomy, pár 17 genetika MeSH
- mutace MeSH
- mutační analýza DNA MeSH
- myelodysplastické syndromy genetika MeSH
- nádorový supresorový protein p53 genetika MeSH
- retrospektivní studie MeSH
- sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- variabilita počtu kopií segmentů DNA MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- ztráta heterozygozity genetika MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Dicentric chromosomes (DCs) have been described in many hematological diseases, including acute myeloid leukemia (AML). They are markers of cancer and induce chromosomal instability, leading to the formation of other chromosomal aberrations and the clonal evolution of pathological cells. Our knowledge of the roles and behavior of human DCs is often derived from studies of induced DCs and cell lines. It is difficult to identify all the DCs in the karyotypes of patients because of the limitations of metaphase cytogenetic methods. The aim of this study was to revise the karyotypes of 20 AML patients in whom DCs were found with conventional G-banding or multicolor fluorescence in situ hybridization (mFISH) with (multi)centromeric probes and to characterize the DCs at the molecular cytogenetic level. FISH analyses confirmed 23 of the 29 expected DCs in 18 of 20 patients and identified 13 others that had not been detected cytogenetically. Fourteen DCs were altered by other chromosomal changes. In conclusion, karyotypes with DCs are usually very complex, and we have shown that they often contain more than one DC, which can be missed with conventional or mFISH methods. Our study indicates an association between number of DCs in karyotype and very short survival of patients.
- MeSH
- abnormální karyotyp * MeSH
- akutní myeloidní leukemie genetika mortalita MeSH
- hybridizace in situ fluorescenční * MeSH
- lidé středního věku MeSH
- lidé MeSH
- lidské chromozomy genetika MeSH
- míra přežití MeSH
- nádorové buněčné linie MeSH
- přežití po terapii bez příznaků nemoci MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- klinické zkoušky MeSH
- práce podpořená grantem MeSH
U 10–20 % nemocných s myelodysplastickými syndromy (MDS) je nalézán komplexní karyotyp, který je spojen s vysokým rizikem transformace do akutní myeloidní leukemie (AML) a špatnou prognózou. Jedním z jevů, které se mohou podílet na zvýšené genomové nestabilitě buněk kostní dřeně u nemocných s MDS, je získaná uniparentální disomie (aUPD), tj. stav, kdy obě kopie určitého chromozomu nebo jeho části pochází od jednoho rodiče. Patologický potenciál této změny, která vzniká jako klonální aberace v některých somatických buňkách, spočívá v přítomnosti homozygotních mutací tumor supresorových genů a onkogenů. Cílem studie bylo zjistit frekvenci a význam uniparentální disomie (UPD) v souboru 57 nemocných s MDS a komplexním karyotypem za použití array komparativní genomové hybridizace kombinované s detekcí jednonukleotidových polymorfismů (aCGH/SNP). V souboru 57 nemocných bylo nalezeno celkem 40 oblastí UPD u 21 pacientů (36,8 %). U zhruba poloviny nálezů šlo o sporadický výskyt (19/40). U šesti pacientů byly detekovány UPD na chromozomu X lokalizované v oblastech Xp22.11–Xp22.2 (4/6) a Xq13.3–Xq21.1 (2/6) a u dvou pacientů byla pozorována UPD 17q s proměnlivým rozsahem v pruzích 17q22 až 17q24.2. Nejčastějším nálezem byla aUPD krátkých ramen chromozomu 17, která byla detekována celkem u 13/57 pacientů (22,8 %). U všech 13 pacientů mutační analýza potvrdila homozygotní mutaci genu TP53, z toho dvě nalezené posunové (frameshift) mutace nebyly dosud popsány v databázi IARC (International Agency for Research on Cancer TP53 database). Nález byl spojen s velmi špatnou prognózou (medián přežití 4 měsíce). Vzhledem k četnosti výskytu ve studovaném souboru byla aUPD 17p silně asociována s komplexním karyotypem na rozdíl od jiných v literatuře dosud popsaných oblastí aUPD (1p, 4q, 7q, 11q, 13q, 21q), které nebyly v souboru detekovány vůbec. Oblasti UPD se jeví při analýzách metodami klasické a molekulární cytogenetiky jako balancované, tedy bez změny počtu kopií DNA. Čipové technologie s detekcí jednonukleotidových polymorfismů jsou ideální metodou pro identifikaci a bližší charakterizaci oblastí UPD a s nimi souvisejících genů významných pro vznik a progresi onemocnění.
Complex karyotypes are seen in approximately 20% of patients with myelodysplastic syndromes (MDS) and are associated with a high risk of transformation into acute myeloid leukaemia (AML) and poor prognosis. Acquired uniparental disomy (aUPD, i.e. both copies of a chromosome pair or its part originate from one parent) may contribute to increased genomic instability in bone-marrow cells of patients with MDS. The pathological potential of aUPD, which arises as a clonal aberration in a proportion of somatic cells, involves tumour suppressor gene and oncogene homozygous mutations. The aim of this study was to evaluate the frequency and implications of uniparental disomy (UPD) in a cohort of 57 patients with MDS and complex karyotype using array comparative genomic hybridization with detection of single nucleotide polymorphisms (aCGH/SNP). UPD was found to be present in 40 regions in 21 of 57 patients (36.8%). Almost half of these involved non-recurrent changes (19/40). Chromosome X UPD was detected in six patients (Xp22.11–Xp22.2 in four and Xq13.3–Xq21.1 in two, respectively). UPD of 17q with a variable extent from 17q22 to 17q24.2 was observed in two patients. The most common finding was aUPD of the short arm of chromosome 17, which was detected in 13 of 57 patients (22.8%). Mutational analysis confirmed a homozygous mutation of the TP53 gene in all samples with this finding, including two frameshift mutations that are not registered in the IARC (International Agency for Research on Cancer TP53) database. This finding correlated with very poor prognosis (median OS 4 months). aUPD 17p was strongly associated with complex karyotype in the studied cohort. However, other previously published aUPDs in MDS (1p, 4q, 7q, 11q, 13q, 21q) were not found in our study. UPD regions appear to be balanced (i.e. without change of DNA copies) by conventional and molecular cytogenetic methods. Therefore, aCGH/SNP represents an ideal method for the identification and further characterization of UPDs and affected genes significant for disease development and progression.
- Klíčová slova
- komplexní karyotyp, refrakterní cytopenie s multilineární dysplazií,
- MeSH
- akutní myeloidní leukemie genetika MeSH
- analýza přežití MeSH
- chromozomální delece MeSH
- dospělí MeSH
- geny p53 * genetika MeSH
- homozygot MeSH
- jednonukleotidový polymorfismus MeSH
- karyotyp MeSH
- lidé středního věku MeSH
- lidé MeSH
- lidské chromozomy, pár 17 genetika MeSH
- mutace MeSH
- mutační analýza DNA MeSH
- myelodysplastické syndromy * genetika MeSH
- refrakterní anemie s nadbytkem blastů genetika MeSH
- retrospektivní studie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- srovnávací genomová hybridizace statistika a číselné údaje MeSH
- uniparentální disomie * genetika MeSH
- vyšetřování kostní dřeně MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- práce podpořená grantem MeSH
