Long-molecule scars of backup DNA repair in BRCA1- and BRCA2-deficient cancers.

Homologous recombination (HR) deficiency is associated with DNA rearrangements and cytogenetic aberrations1. Paradoxically, the types of DNA rearrangements that are specifically associated with HR-deficient cancers only minimally affect chromosomal structure2. Here, to address this apparent contradiction, we combined genome-graph analysis of short-read whole-genome sequencing (WGS) profiles across thousands of tumours with deep linked-read WGS of 46 BRCA1- or BRCA2-mutant breast cancers. These data revealed a distinct class of HR-deficiency-enriched rearrangements called reciprocal pairs. Linked-read WGS showed that reciprocal pairs with identical rearrangement orientations gave rise to one of two distinct chromosomal outcomes, distinguishable only with long-molecule data. Whereas one (cis) outcome corresponded to the copying and pasting of a small segment to a distant site, a second (trans) outcome was a quasi-balanced translocation or multi-megabase inversion with substantial (10 kb) duplications at each junction. We propose an HR-independent replication-restart repair mechanism to explain the full spectrum of reciprocal pair outcomes. Linked-read WGS also identified single-strand annealing as a repair pathway that is specific to BRCA2 deficiency in human cancers. Integrating these features in a classifier improved discrimination between BRCA1- and BRCA2-deficient genomes. In conclusion, our data reveal classes of rearrangements that are specific to BRCA1 or BRCA2 deficiency as a source of cytogenetic aberrations in HR-deficient cells.

Comprehensive evaluation of genetic variants using chromosomal microarray analysis and exome sequencing in fetuses with congenital heart defect.

OBJECTIVE: To evaluate comprehensively, using chromosomal microarray analysis (CMA) and exome sequencing (ES), the prevalence of chromosomal abnormalities and sequence variants in unselected fetuses with congenital heart defect (CHD) and to evaluate the potential diagnostic yields of CMA and ES for different CHD subgroups. METHODS: This was a study of 360 unselected singleton fetuses with CHD detected by echocardiography, referred to our department for genetic testing between February 2018 and December 2019. We performed CMA, as a routine test for aneuploidy and copy number variations (CNV), and then, in cases without aneuploidy or pathogenic CNV on CMA, we performed ES. RESULTS: Overall, positive genetic diagnoses were made in 84 (23.3%) fetuses: chromosomal abnormalities were detected by CMA in 60 (16.7%) and sequence variants were detected by ES in a further 24 (6.7%) cases. The detection rate of pathogenic and likely pathogenic genetic variants in fetuses with non-isolated CHD (32/83, 38.6%) was significantly higher than that in fetuses with isolated CHD (52/277, 18.8%) (P < 0.001), this difference being due mainly to the difference in frequency of aneuploidy between the two groups. The prevalence of a genetic defect was highest in fetuses with an atrioventricular septal defect (36.8%), ventricular septal defect with or without atrial septal defect (28.4%), conotruncal defect (22.2%) or right ventricular outflow tract obstruction (20.0%). We also identified two novel missense mutations (c.2447G>C, p.Arg816Pro; c.1171C>T, p.Arg391Cys) and a new phenotype caused by variants in PLD1. CONCLUSIONS: Chromosomal abnormalities were identified in 16.7% and sequence variants in a further 6.7% of fetuses with CHD. ES should be offered to all pregnant women with a CHD fetus without chromosomal abnormality or pathogenic CNV identified by CMA, regardless of whether the CHD is isolated. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Methylation of Promoters of Apoptosis-Related Genes in Blood Lymphocytes of Workers Exposed to Occupational External Irradiation.

We studied the effect of technogenic radiation on the degree of promoter methylation in genes involved in apoptosis in blood lymphocytes of workers exposed to long-term γ-radiation during their professional activities. Blood samples for the analysis were obtained from 11 conventionally healthy men aged from 54 to 71 years (mean 66 years), workers of the Siberian Group of Chemical Enterprises working experience from 27 to 40 years (mean 30 years); the external exposure dose was 175.88 mSv (158.20-207.81 mSv). In all examined subjects, the degree of methylation of the promoters of apoptosis-related genes ranged from 0.22 to 50.00%. A correlation was found between the degree of methylation of BCLAF1 promoters (p=0.035) with the age of workers, BAX promoters (p=0.0289) with high content of aberrant cells, and APAF1 promoters (p=0.0152) with increased number of dicentric chromosomes. A relationship was found between the dose of external irradiation and the degree of methylation of gene promoters of BAD (p=0.0388), BID (р=0.0426), and HRK (р=0.0101) genes.

Risk factors associated with fetal pleural effusion in prenatal diagnosis: a retrospective study in a single institute in Southern China.

The aim of this study was to analyse the factors associated with fetal pleural effusion over the past five years in a single institute in the South of China. Between January 2011 and May 2016, 129 foetuses with pleural effusion were referred to the Fetal Medicine Unit in Guangzhou's Women and Children's Medical Center. Seventy-nine women accepted an invasive procedure to rule out chromosomal abnormalities, fetal anaemia, intrauterine infections or some of the submicroscopic chromosomal abnormalities. Our results showed that chromosomal anomalies occurred in 15.2% (12/79) of cases including 8 Turner syndrome (45, X) (10.1%), 3 trisomy 21 (3.8%) and 1 trisomy 13 (1.3%). Pathological microdeletion or microduplication syndrome occurred in 3 out of 36 (8.3%) prenatal samples with normal karyotype and structural defects. Eight foetuses (10.1%) affected with haemoglobin Bart's disease showed pleural effusion at second or third trimester. Two cases (2.5%) were found to have an intrauterine infection. In conclusion, fetal pleural effusion has a close correlation with chromosomal abnormality. CMA may increase the detection rate of chromosomal aberrations, especially for micro-deletion or micro-duplication syndromes. In the South of China, Thalassemia must be considered when a fetal pleural effusion is detected.Impact statementWhat is already known on this subject? The aetiology of fetal pleural effusion includes a chromosomal abnormality, a congenital heart disease, congenital infections and a number of genetic syndromes.What do the results of this study add? This is the first retrospective study to analyse the aetiology of fetal pleural effusion in one institute in the South of China.What are the implications of these findings for clinical practice and/or further research? Besides the chromosomal abnormality, micro-deletion and micro-duplication syndromes were also detected in our study. We feel that thalassemia must be considered when fetal pleural effusion is detected in South China.

Reproductive success of assisted reproductive technology in couples with chromosomal abnormalities.

PURPOSE: Infertility is estimated to affect 15% of couples, having chromosome abnormalities an important role in its etiology. The main objective of this work was to access the reproductive success of ART in infertile couples with chromosomal abnormalities comparing to a control group with normal karyotype. METHODS: A 7-year retrospective karyotype analysis of infertile couples was done. Data regarding type of infertility, couples' ages, ART performed, and their reproductive success were obtained. Adjusted odds ratio (OR) were used to estimate magnitude of association between the reproductive success and the different groups. RESULTS: We found a prevalence of 7.83% of chromosome abnormalities in our population (233 couples out of 2989). Chromosomal anomalies were found in 82 men (34.75%) and 154 women (65.25%), with low-grade mosaicism being the most prevalent (50.85%), followed by autosomal translocations (17.37%) and sex chromosomes abnormalities (13.56%). Only 2359 couples were treated with ART. There was a non-significant lower reproductive success rate in the cases (OR = 0.899, p = 0.530) with IVF providing the higher success rate. In general, female carriers of chromosome anomalies had a higher success rate, although not significant. CONCLUSION: Although the differences regarding success rate between groups were not found statistically significant, we still advocate that cytogenetic analysis should be performed routinely in all infertile couples namely before ART. This might help deciding the best treatment options including Preimplantation Genetic Testing for aneuploidies or structural rearrangements and minimize the risk of transmission of anomalies to the offspring.

Treatment of multiple myeloma with high-risk cytogenetics: a consensus of the International Myeloma Working Group.

The International Myeloma Working Group consensus updates the definition for high-risk (HR) multiple myeloma based on cytogenetics Several cytogenetic abnormalities such as t(4;14), del(17/17p), t(14;16), t(14;20), nonhyperdiploidy, and gain(1q) were identified that confer poor prognosis. The prognosis of patients showing these abnormalities may vary with the choice of therapy. Treatment strategies have shown promise for HR cytogenetic diseases, such as proteasome inhibition in combination with lenalidomide/pomalidomide, double autologous stem cell transplant plus bortezomib, or combination of immunotherapy with lenalidomide or pomalidomide. Careful analysis of cytogenetic subgroups in trials comparing different treatments remains an important goal. Cross-trial comparisons may provide insight into the effect of new drugs in patients with cytogenetic abnormalities. However, to achieve this, consensus on definitions of analytical techniques, proportion of abnormal cells, and treatment regimens is needed. Based on data available today, bortezomib and carfilzomib treatment appear to improve complete response, progression-free survival, and overall survival in t(4;14) and del(17/17p), whereas lenalidomide may be associated with improved progression-free survival in t(4;14) and del(17/17p). Patients with multiple adverse cytogenetic abnormalities do not benefit from these agents. FISH data are implemented in the revised International Staging System for risk stratification.

Traditional and molecular chromosomal abnormality analysis of products of conception in spontaneous and recurrent miscarriage.

Chromosome abnormalities account for half of the recorded miscarriages. Data from cytogenetic analysis of the products of conception (POC) in miscarriages are reviewed in the paper. Genetic analysis of POC allows patients to be given prognostic information. Molecular genetic techniques can overcome the pitfalls of conventional karyotyping, such as culture failure and trace submicroscopic abnormalities. We compare the pros and cons when these technologies are applied to the analysis of POC after miscarriage. Guidance is also provided for future clinical applications. The objective of the review is to help clinicians understand the limitations and to optimise the usefulness of genetic analysis of POC. TWEETABLE ABSTRACT: Genetics and POC of miscarriage.

Describing sequencing results of structural chromosome rearrangements with a suggested next-generation cytogenetic nomenclature.

With recent rapid advances in genomic technologies, precise delineation of structural chromosome rearrangements at the nucleotide level is becoming increasingly feasible. In this era of "next-generation cytogenetics" (i.e., an integration of traditional cytogenetic techniques and next-generation sequencing), a consensus nomenclature is essential for accurate communication and data sharing. Currently, nomenclature for describing the sequencing data of these aberrations is lacking. Herein, we present a system called Next-Gen Cytogenetic Nomenclature, which is concordant with the International System for Human Cytogenetic Nomenclature (2013). This system starts with the alignment of rearrangement sequences by BLAT or BLAST (alignment tools) and arrives at a concise and detailed description of chromosomal changes. To facilitate usage and implementation of this nomenclature, we are developing a program designated BLA(S)T Output Sequence Tool of Nomenclature (BOSToN), a demonstrative version of which is accessible online. A standardized characterization of structural chromosomal rearrangements is essential both for research analyses and for application in the clinical setting.

A patch-based tensor decomposition algorithm for M-FISH image classification.

Multiplex-fluorescence in situ hybridization (M-FISH) is a chromosome imaging technique which can be used to detect chromosomal abnormalities such as translocations, deletions, duplications, and inversions. Chromosome classification from M-FISH imaging data is a key step to implement the technique. In the classified M-FISH image, each pixel in a chromosome is labeled with a class index and drawn with a pseudo-color so that geneticists can easily conduct diagnosis, for example, identifying chromosomal translocations by examining color changes between chromosomes. However, the information of pixels in a neighborhood is often overlooked by existing approaches. In this work, we assume that the pixels in a patch belong to the same class and use the patch to represent the center pixel's class information, by which we can use the correlations of neighboring pixels and the structural information across different spectral channels for the classification. On the basis of assumption, we propose a patch-based classification algorithm by using higher order singular value decomposition (HOSVD). The developed method has been tested on a comprehensive M-FISH database that we established, demonstrating improved performance. When compared with other pixel-wise M-FISH image classifiers such as fuzzy c-means clustering (FCM), adaptive fuzzy c-means clustering (AFCM), improved adaptive fuzzy c-means clustering (IAFCM), and sparse representation classification (SparseRC) methods, the proposed method gave the highest correct classification ratio (CCR), which can translate into improved diagnosis of genetic diseases and cancers. © 2016 International Society for Advancement of Cytometry.

Role of molecular-genetic abnormalities in pathogenesis and risk stratification of multiple myeloma.

Over the past decades the studies have greatly improved our understanding of the molecular basis of multiple myeloma (MM) and mechanisms of disease progression. The majority of the most widespread chromosomal aberrations, revealing in MM, has independent predictive value and influence on a choice of optimal treatment. There were observed 190 MM patients in hematologic hospitals of St. Petersburg. Genetic anomalies (GA) were detected at 3l,3% of patients and did not depend on their age. Patients with ISS III had a detectability of GA higher than with ISS II and ISS I (48,°% (24/5°), 2l,2% (7/33) and 27,6% (8/29)). Translocation t(ll;l4) was found in 23,3% (3O/129) patients; dell3q - 20,8% (27/13°); dell7p - at 8,4% (7/83); t(4;l4) - at 6,9% (9/13O), that allowed to stratify patients in groups of risk according to mSMART version l. O and 2. O. Median overall survival (OS) modified mSMART l. O in group of standard risk was 7° months, high risk - 47,l months. Median OS mSMART 2. O in group of standard risk was 7° months, intermediate risk - 47 months, high risk - 45 months. OS did not depend on age, clinical manifestations, treatment and other factors.

Genetics factors associated with myelodysplastic syndromes.

The myelodysplastic syndromes (MDS) are a clinically and cytogenetically heterogeneous group of clonal diseases. Clonal chromosomal abnormalities are observed in 30-50% of patients with MDS. The deletions are among the most common alterations, and often involve the long arms of chromosomes 5, 7, 8, 13, and 20 and the short arms of chromosomes 12 and 17. The advent of new technologies for the detection of genetic abnormalities led to the description of a new set of recurrent mutations, leading to new insights into the pathophysiology of MDS. The recent recognition that genes involved in the regulation of histone function (EZH2, ASXL1, and UTX) and DNA methylation (DNMT3A, IDH1/IDH2, and TET2) are frequently mutated in MDS, has led to the proposal that there is an important link between genetic and epigenetic alterations in this disease. In fact, regulatory factors have also been considered as miR-143/miR-145, miR-146a, miR-125a and MiR-21. Somatic mutations may influence the clinical phenotype but are not included in current prognostic scoring systems. In recent years research has brought new insights into these diseases, but few of the findings are sufficiently robust to be incorporated into the clinical routine at this time. Thus, the aim of this study was to review the role of genetic factors involved in the diagnosis and development of the different phenotypes of MDS.

[CHROMOSOMAL ABNORMALITIES IN PATIENTS WITH INFERTILITY].

To assess the frequency and structure of chromosomal abnormalities in patients with infertility, a retrospective analysis of cytogenetic studies of 3414 patients (1741 females and 1673 males), referred to the Clinic of reproductive medicine "Nadiya" from 2007 to 2012, was performed. Chromosomal abnormalities were detected in 2.37% patients: 2.79% in males and 1.95% in females. Balanced structural chromosomal abnormalities prevailed over numerical abnormalities and corresponded to 80.2% of all chromosomal abnormalities detected in the studied group. Sex chromosome abnormalities made up 23.5% of chromosomal pathology (19/81) and included gonosomal aneuploidies in 84% of cases (16/19) and structural abnormalities of chromosome Y in 16% of cases (3/19). The low level sex chromosome mosaicism was detected with the frequency of 0.55%. Our results highlight the importance of cytogenetic studies in patients seeking infertility treatment by assisted reproductive technologies, since an abnormal finding not only provide a firm diagnosis to couples with infertility, but also influences significantly the approach to infertility treatment in such patients.

Sufficiency of FNAB aspirates of posterior uveal melanoma for cytologic versus GEP classification in 159 patients, and relative prognostic significance of these classifications.

OBJECTIVE: To determine the relative sufficiency of paired aspirates of posterior uveal melanomas obtained by FNAB for cytopathology and GEP, and their prognostic significance for predicting death from metastasis. METHODS: Prospective non-randomized IRB-approved single-center longitudinal clinical study of 159 patients with posterior uveal melanoma sampled by FNAB in at least two tumor sites between 09/2007 and 12/2010. Cases were analyzed with regard to sufficiency of the obtained aspirates for cytopathologic classification and GEP classification. Statistical strength of associations between variables and GEP class was computed using Chi-square test. Cumulative actuarial survival curves of subgroups of these patients based on their cytopathologic versus GEP-assigned categories were computed by the Kaplan-Meier method. The endpoint for this survival analysis was death from metastatic uveal melanoma. RESULTS: FNAB aspirates were insufficient for cytopathologic classification in 34 of 159 cases (21.9 %). In contrast, FNAB aspirates were insufficient for GEP classification in only one of 159 cases (0.6 %). This difference is statistically significant (P < 0.001). Six of 34 tumors (17.6 %) that yielded an insufficient aspirate for cytopathologic diagnosis were categorized as GEP class 2, while 43 of 125 tumors (34.7 %) that yielded a sufficient aspirate for cytopathologic diagnosis were categorized as GEP class 2. To date, 14 of the 49 patients with a GEP class 2 tumor (28.6 %) but only five of the 109 patients with a GEP class 1 tumor (5.6 %) have developed metastasis. Fifteen of 125 patients (12 %) whose tumors yielded sufficient aspirates for cytopathologic classification but only four of 34 patients (11.8 %) whose tumors yielded insufficient aspirates for cytopathologic classification developed metastasis. The median post-biopsy follow-up time for surviving patients in this series was 32.5 months. Cumulative actuarial 5-year probability of death from metastasis 14.1 % for those with an insufficient aspirate for cytopathologic classification versus 22.4 % for those with a sufficient aspirate for cytopathologic classification (log rank P = 0.68). In contrast, the cumulative actuarial 5-year probability of metastatic death was 8.0 % for those with an insufficient/unsatisfactory aspirate for GEP classification or GEP class 1 tumor, versus 45.0 % for those with a GEP class 2 tumor (log rank P = 0.005). CONCLUSION: This study confirmed that GEP classification of posterior uveal melanoma cells obtained by FNAB is feasible in almost all cases, including most in which FNAB yields an insufficient aspirate for cytodiagnosis. The study also confirmed that GEP classification is substantially better than cytologic classification for predicting subsequent metastasis and metastatic death.

[Complex chromosomal rearrangements: a paradigm for the study of chromosomal instability]. / Les remaniements chromosomiques complexes - un paradigme pour l'étude de l'instabilité chromosomique.

Complex chromosomal rearrangements (CCR) include diverse structural anomalies leading to complex karyotypes which are difficult to interpret. Although karyotype analysis has been able to identify a large number of these rearrangements and to distinguish de novo and familial events, it is the advent of molecular cytogenetic and sequence analysis techniques which have led to an understanding of the molecular mechanisms underlying the formation of CCR. The diversity and high level of complexity inherent to CCR raises questions about their origin, their ties to chromosome instability and their impact in pathology. Today it is possible to precisely characterize CCR and to offer carriers sophisticated diagnostic techniques, such as preimplantation diagnosis. However, the meiotic segregation of these rearrangements remains very complex.

[Aneuploidies in oocytes used in IVF programs].

The aim of the study was to investigate with FISH the frequency of aneuploidies of the first and second polar bodies (PB-I and PB-II) of oocytes in women participating in IVF programs. The study included 93 women, 82 of them were after controlled ovulation stimulation (COS), 11 in natural cycles. FISH in 238 PB-I and PB-II was done. Revealed that the frequency of aneuploidies in oocytes after COS was higher than in the natural cycle, and also was higher after COS in women with infertility compared to women stimulated because of male infertility and donors of oocytes. Aneuploidies of oocytes after COS are more common in patients after 35 years old. Thus, the study of aneuplodies of PB-I and PB-II by FISH is an informative tool of pregestation genetic diagnosis.

[Identification of human small supernumerary marker chromosomes and discussion of its research value].

OBJECTIVE: To identify the origin of human small supernumerary marker chromosomes (sSMCs) using fluorescent in situ hybridization (FISH) combined with G-banding karyotype analysis, and to discuss their mechanisms of formation and research value. METHODS: Cep-FISH and SubcenM-FISH were used to analyze sSMCs in 3 patients for whom the result of G-banding was 47,XN,+mar. RESULTS: The FISH result of case 1 was 47,XY,+mar.ish inv dup(22)(q11.1)(D22Z4++,D14/22Z1+, RP11-172D7-). The marker has formed exclusively by heterochromatin. A boy was delivered later with no apparent clinical abnormalities. The FISH result of case 2 was 47,XX,+mar.ish r(10)(p11.2q11.2) (cep10+, RP11-232C13+, RP11-178A10+)[25]/46,XX[10]. The marker has formed by heterochromatin and nearby centromere. A girl was delivered later with no clinical abnormalities. The FISH result of case 3 was 47,XY,+mar.ish inv dup(22)(q11.1)(D22Z4+,D14/22Z1+). The marker has also formed exclusively by euchromatin. Fetal abnormalities were detected by type B ultrasonography, but were not necessarily related with the marker. CONCLUSION: The diversity of sSMCs has posed a great challenge for prenatal diagnosis. Identification of sSMCs will require combined karyotype analysis and FISH or other molecular techniques such as microarray based comparative genomic hybridization or sequencing. For its specific structure, the sSMCs may also provide a valuable tool for gene mapping, heterochromatin research and gene therapy.

[Comparative analysis of cytogenetic examination of control groups of subjects carried out in different Russian laboratories].

The incidence of unstable chromosome aberrations in peripheral blood lymphocytes from unirradiated control subjects was analyzed using cytogenetic data obtained from 9 cytogenetic laboratories located in Moscow, St.-Petersburg, Obninsk, and Dubna (Russia). The objective of this study was to estimate the level and spectrum of spontaneous chromosome aberrations in human lymphocytes. 1140 blood samples were taken from 1112 subjects (594 men and 546 women) aged 1 to 72. The total metaphase number was 466795. The uniform Giemsa method for peripheral blood lymphocyte cultures was used. After counting 466795 metaphases, 4288 chromosomal aberrations of various types were classified. The most frequent types of aberrations were acentrics and chromatid deletions. They made up 90% of the total number of aberrations. The remaining 10% were exchange aberrations. The number of chromosome exchanges (dicentrics and centric rings) was twice the number of chromatid exchanges. Overall, the portion ofcells with chromosomal or (and) chromatid aberrations was 0.89 +/- 0.01%; the frequency of acentrics was 0.29 +/- 0.01; the frequency of dicentrics was 0.046 +/- 0.003; the frequency of unstable chromosome aberrations was 0.35 +/- 0.01; and the frequency of chromatid aberrations was 0.57 +/- 0.01 per 100 cells.

Field effect in oral precancer as assessed by DNA flow cytometry and array-CGH.

OBJECTIVE: 'Field cancerization' is an accepted model for oral carcinogenesis. So far, genetically altered fields have been just reported in the presence of carcinomas. This study assessed the distant mirror fields (MFs) of oral precancer by DNA high-resolution flow cytometry (hr DNA-FCM) and array-Comparative Genomic Hybridization (a-CGH). METHODS: Five leukoplakias without dysplasia (OLs), seven dysplastic leukoplakias (DOLs), and 12 corresponding visually normal and non-dysplastic MFs were analyzed. DNA aneuploidy (DNA Index, DI ≠ 1) was detected by hr DNA-FCM on DAPI stained nuclei suspensions. The epithelial DNA aneuploid subclones were FCM-sorted to obtain genomic DNA for a-CGH. RESULTS: Mirror fields, OLs, and DOLs showed increasing prevalence of DNA aneuploidy of, respectively, 8%, 20%, and 57%. The average number of chromosome aberrations (Ch-Abs) was 2.8 in MFs, 3 in OLs, and 10.6 in DOLs. MFs relative to OLs and DOLs had average numbers of Ch-Abs, respectively, of 1.8 and 3.6. Ch-Abs were also observed in DNA diploid sublines, and often the same aberrations were observed in both MFs and corresponding OLs/DOLs. CONCLUSION: DNA aneuploidy and Ch-Abs in MFs, the last ones being mainly gains, indicate an early onset of field effect in oral carcinogenesis.

Chromosomal aberrations in minor salivary gland pleomorphic adenoma.

PURPOSE: Cytogenetic analysis of a pleomorphic adenoma (PA) arising in the major salivary glands, in particular the parotid, is well documented, with chromosome 8 being the most commonly involved aberration, mainly in t(3;8). However, cytogenetic studies of PA in the minor salivary glands (MSGs) are rare and, to the authors' knowledge, only 3 reports have been published. The authors investigated the cytogenetic abnormalities of a series of 6 PAs arising from MSGs and compared these with published findings from the parotid gland to determine whether the karyotype was the same in the 2 sites. MATERIALS AND METHODS: Six fresh samples of MSG PA were examined by classic cytogenetic analysis. The tissue was minced and cultured in RPMI-1640 medium. The cells were fixed after 2 to 8 days of culture and analyzed according to standard procedures. More than 25 metaphases were analyzed on G-banded slides, and the karyotype was described according to International System for Human Cytogenetic Numenclature guidelines. RESULTS: The spectrum of chromosomal aberrations found in the MSG PAs was similar to those reported in the major salivary glands in all 6 cases. CONCLUSIONS: Cytogenetically, there would seem to be no clear differences in PAs arising from the major salivary glands versus the MSGs. It is unknown whether the underlying tumorigenesis and chromosomal aberrations of PAs from major salivary glands and MSGs are similar, although the proportion of malignant tumors arising from the MSGs is much larger compared with the parotid. Further studies are needed in this area.

Monosomal karyotype provides better prognostic prediction after allogeneic stem cell transplantation in patients with acute myelogenous leukemia.

We studied cytogenetic risk grouping schemes to stratify patients with acute myelogenous leukemia (AML) (n = 212) into prognostically distinct subgroups for relapse incidence (RI), progression-free survival (PFS), and overall survival (OS) after allogeneic hematopoietic stem cell transplantation (HSCT). Patients were divided according to cytogenetic abnormalities based on the Medical Research Council, Southwest Oncology Group, Cancer and Leukemia Group B (CALGB), Dana-Farber, and recently described monosomal karyotype (MK) classification schemes and analyzed separately for first complete remission (CR1; n = 134) and beyond (CR2+; n = 78). Multivariate analysis was performed after adjusting for age, conditioning intensity, donor type, and cytomegalovirus serology status. Although none of the covariates was associated with OS in CR1, the presence of MK (MK(+)) was associated with worse RI and PFS (hazard ratio [HR], 3.3, P = .01 and HR, 2.0, P = .05, respectively). No other classification scheme was predictive of outcomes in CR1. In CR2+, for RI, only MK(+) was predictive of poor outcome (HR, 3.7; P = .03). For PFS, all 5 classification schemes were predictive, and for OS, both the MK(+) and CALGB adverse karyotypes were predictive. In addition to cytogenetics, nonmyeloablative conditioning was associated with decreased PFS and OS in patients in CR2+ in all models. Our results indicate that among all classification schemes, MK classification can identify a subgroup with very poor prognosis in patients with AML after allogeneic HSCT.