Performance of conventional cytogenetic analysis on chorionic villi when only one cell layer, cytotrophoblast or mesenchyme alone, is analyzed.

OBJECTIVE: To provide an estimation of the probability of error when chorionic villi (CV) cytogenetic analysis is limited to a single placental layer; either a direct preparation (Dir) or long-term culture (LTC). METHODS: We retrospectively reviewed cytogenetic studies on 81,593 consecutive CV samples in which both Dir and LTC were analyzed. All mosaic cases received amniocentesis. The false omission and false discovery rates were calculated by assessing the results that would have been reported when analysis was limited to either Dir or LTC. RESULTS: For all abnormalities combined, the proportion of normal Dir or LTC only reports that would have been inconsistent with a subsequent amniocentesis was 0.09% and 0.03%, respectively (false omissions). Among abnormal reports based on Dir or LTC alone, 8.01% and 3.17%, respectively, would be inconsistent with a subsequent amniocentesis result (false discoveries). Differences are present for individual abnormalities. CONCLUSIONS: From the perspective of identifying all abnormalities of potential clinical significance, the analysis of both placental layers is optimal. LTC alone is the preferred approach if only one layer of placenta is to be analyzed. Although rare, it is important to acknowledge that one cell layer analysis alone can cause misdiagnosis due to undetected mosaicism.

Increased Fetal Chromosome Detection with the Use of Operative Hysteroscopy During Evacuation of Products of Conception for Diagnosed Miscarriage.

STUDY OBJECTIVE: To determine whether incorporation of operative hysteroscopy with biopsy of products of conception, in conjunction with a suction curettage for a first trimester missed abortion, affected the rate of maternal cell contamination when chromosomal analysis was performed on the products of conception, and to determine the rates of retained products of conception with incorporation of hysteroscopy after suction curettage. DESIGN: Retrospective chart study. SETTING: Private, minimally invasive surgery and infertility practice with academic-community hospital affiliation. PATIENTS: Infertility patients undergoing evacuation of products of conception for documented first trimester miscarriages between 2006 and 2017. INTERVENTIONS: Suction curettage or hysteroscopic biopsy and suction curettage, followed by chromosomal analysis of products of conception for determination of fetal genetics. MEASUREMENTS AND RESULTS: A total of 264 charts were analyzed. Patients were categorized into 2 groups based on surgical collection of products of conception: group 1 (N = 174), suction curettage only, and group 2 (N = 90), a single procedure consisting of operative hysteroscopy with biopsy of products of conception followed by suction curettage and then diagnostic hysteroscopy to look for retained products. Data for chromosome detection and retained products of conception were available for 246 and 239 patients, respectively. No significant differences were detected between the groups for age, body mass index, ethnicity, gravida, parity, primary infertility, secondary infertility, spontaneous conception, single or multiple gestation, and surgical complications. Fetal chromosome detection was significantly higher without maternal contamination in group 2 (88.5%) compared with group 1 (64.8%) (p < .001). There was no significant between-group difference in postoperative retained products of conception. CONCLUSION: Obtaining fetal genetics can be useful when planning for a future successful pregnancy. The addition of operative hysteroscopy to biopsy the gestational sac, chorionic villi, and/or fetus significantly decreases the risk of maternal contamination and increases the ability to detect fetal chromosomes for genetic analysis without an increased risk of surgical complications. Despite the low risk of surgical complications, immediate second-look hysteroscopy after the completion of suction evacuation does not reduce the risk of postoperative retained products of conception.

Should cell-free DNA testing be used in pregnancy with increased fetal nuchal translucency?

OBJECTIVE: To assess the frequency of atypical chromosomal and submicroscopic anomalies, as well as fetal structural abnormalities, observed on first-trimester ultrasound scan in fetuses with nuchal translucency (NT) thickness > 99th centile, in order to evaluate the suitability of using standard cell-free DNA (cfDNA) testing as the sole screening test in these pregnancies. METHODS: This was a retrospective cohort study of 226 fetuses with NT > 99th centile at 11-14 weeks' gestation, between January 2013 and December 2017, in a clinical setting in which greater than 95% of pregnant women receive first-trimester combined screening. All patients underwent genetic testing by means of quantitative fluorescence polymerase chain reaction and chromosomal microarray analysis, mainly in chorionic villus samples. We assessed the theoretical yield of two cfDNA testing models, targeted cfDNA (chromosomes 21, 18 and 13) and extended cfDNA (chromosomes 21, 18, 13 and sex chromosomes), and compared it with that of cytogenetic testing and ultrasound assessment in the first and second or third trimesters. RESULTS: In the 226 fetuses analyzed, cytogenetic testing revealed 84 (37%) anomalies, including 68 typical aneuploidies (involving chromosomes 13, 18 or 21), six sex chromosome aneuploidies (four cases of monosomy X and two of trisomy X), three clinically relevant atypical chromosomal anomalies (one trisomy 22, one trisomy 21 mosaicism and one unbalanced translocation), five submicroscopic pathogenic variants and two cases with Noonan syndrome. Targeted and extended cfDNA testing would miss at least 12% (10/84) and 19% (16/84), respectively, of genetic anomalies, accounting for 4.4% and 7.1% of the fetuses with an increased NT, respectively. Finally, of the 142 fetuses with no identified genetic anomaly, a major fetal malformation was observed in 15 (10.6%) fetuses at the early anomaly scan, and in 19 (13.4%) in the second or third trimester. CONCLUSIONS: cfDNA does not appear to be the appropriate genetic test in fetuses with NT > 99th centile, given that it would miss 12-19% of genetic anomalies in this group. Additionally, first-trimester ultrasound will identify a major structural abnormality in 11% of the fetuses with NT > 99th centile and no genetic anomaly. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

State-wide utilization and performance of traditional and cell-free DNA-based prenatal testing pathways: the Victorian Perinatal Record Linkage (PeRL) study.

OBJECTIVES: To perform individual record linkage of women undergoing screening with cell-free DNA (cfDNA), combined first-trimester screening (CFTS), second-trimester serum screening (STSS), and/or prenatal and postnatal cytogenetic testing with the aim to (1) obtain population-based estimates of utilization of prenatal screening and invasive diagnosis, (2) analyze the performance of different prenatal screening strategies, and (3) report the residual risk of any major chromosomal abnormality following a low-risk aneuploidy screening result. METHODS: This was a retrospective study of women residing in the state of Victoria, Australia, who underwent prenatal screening or invasive prenatal diagnosis in 2015. Patient-funded cfDNA referrals from multiple providers were merged with state-wide results for government-subsidized CFTS, STSS and invasive diagnostic procedures. Postnatal cytogenetic results from products of conception and infants up to 12 months of age were obtained to ascertain cases of false-negative screening results and atypical chromosomal abnormalities. Individual record linkage was performed using LinkageWizTM . RESULTS: During the study period, there were 79 140 births and 66 166 (83.6%) women underwent at least one form of aneuploidy screening. Linkage data were complete for 93.5% (n = 61 877) of women who underwent screening, and of these, 73.2% (n = 45 275) had CFTS alone, 20.2% (n = 12 486) had cfDNA alone; 5.3% (n = 3268) had STSS alone, 1.3% (n = 813) had both CFTS and cfDNA, and < 0.1% (n = 35) had both STSS and cfDNA. CFTS had a combined sensitivity for trisomies 21 (T21), 18 (T18) and 13 (T13) of 89.57% (95% CI, 82.64-93.93%) for a screen-positive rate (SPR) of 2.94%. There were 12 false-negative results in the CFTS pathway, comprising 10 cases of T21, one of T18 and one of T13. cfDNA had a combined sensitivity for T21, T18 and T13 of 100% (95% CI, 95.00-100%) for a SPR of 1.21%. When high-risk cfDNA results for any chromosome (including the sex chromosomes) and failed cfDNA tests were treated as screen positives, the SPR for cfDNA increased to 2.42%. The risk of any major chromosomal abnormality (including atypical abnormalities) detected on prenatal or postnatal diagnostic testing after a low-risk screening result was 1 in 1188 for CFTS (n = 37) and 1 in 762 for cfDNA (n = 16) (P = 0.13). The range of chromosomal abnormalities detected after a low-risk cfDNA result included pathogenic copy-number variants (n = 6), triploidy (n = 3), rare autosomal trisomies (n = 3) and monosomy X (n = 2). CONCLUSIONS: Our state-wide record-linkage analysis delineated the utilization and clinical performance of the multitude of prenatal screening pathways available to pregnant women. The sensitivity of cfDNA for T21, T18 and T13 was clearly superior to that of CFTS. While there was no statistically significant difference in the residual risk of any major chromosomal abnormality after a low-risk CFTS or cfDNA result, there were fewer live infants diagnosed with a major chromosomal abnormality in the cfDNA cohort. These data provide valuable population-based evidence to inform practice recommendations and health policies. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Multi-institutional experience of genetic diagnosis in Ecuador: National registry of chromosome alterations and polymorphisms.

BACKGROUND: Detection of chromosomal abnormalities is crucial in various medical areas; to diagnose birth defects, genetic disorders, and infertility, among other complex phenotypes, in individuals across a wide range of ages. Hence, the present study wants to contribute to the knowledge of type and frequency of chromosomal alterations and polymorphisms in Ecuador. METHODS: Cytogenetic registers from different Ecuadorian provinces have been merged and analyzed to construct an open-access national registry of chromosome alterations and polymorphisms. RESULTS: Of 28,806 karyotypes analyzed, 6,008 (20.9%) exhibited alterations. Down syndrome was the most frequent autosome alteration (88.28%), followed by Turner syndrome (60.50%), a gonosome aneuploidy. A recurrent high percentage of Down syndrome mosaicism (7.45%) reported here, as well as by previous Ecuadorian preliminary registries, could be associated with geographic location and admixed ancestral composition. Translocations (2.46%) and polymorphisms (7.84%) were not as numerous as autosomopathies (64.33%) and gonosomopathies (25.37%). Complementary to conventional cytogenetics tests, molecular tools have allowed identification of submicroscopic alterations regions or candidate genes which can be possibly implicated in patients' symptoms and phenotypes. CONCLUSION: The Ecuadorian National Registry of Chromosome Alterations and Polymorphisms provides a baseline to better understand chromosomal abnormalities in Ecuador and therefore their clinical management and awareness. This data will guide public policy makers to promote and financially support cytogenetic and genetic testing.

Cytogenetic and molecular genetic characterization of KMT2A-PTD positive acute myeloid leukemia in comparison to KMT2A-Rearranged acute myeloid leukemia.

To define the biological differences in acute myeloid leukaemia (AML) with KMT2A gene involvements and their prognostic impact, we compared 190 de novo AML patients at diagnosis, 95 harbouring KMT2A-rearrangement (KMT2Ar) and 95 KMT2A-PTD by performing cytogenetic and molecular genetic analyses. Both AML subtypes had an unfavourable outcome, particularly in patients > 60 years. Patients with KMT2Ar were younger compared to patients with KMT2A-PTD (mean 52 vs 65 years, p < 0.001) and had a higher rate of additional cytogenetic abnormalities (ACA) (46% vs 25% of cases). In both groups, occurrence of ACA did not influence the overall survival (OS). Regarding molecular genetics, 66% of patients with KMT2Ar and 99% of patients with KMT2A-PTD had additional gene mutations. In multivariate analysis, KRAS mutations and 10p12 rearrangement resulted as adverse prognostic factors in KMT2Ar subgroup. In the KMT2A-PTD group, apart from age, only the occurrence of DNMT3A non-R882 mutations correlated with shorter OS.

Next-generation sequencing analysis of embryos from mosaic patients undergoing in vitro fertilization and preimplantation genetic testing.

OBJECTIVE: To investigate the effects of parental mosaicism on their preimplantation embryos. DESIGN: Case series. SETTING: An institute for reproductive and stem cell engineering. PATIENT(S): Sixty-eight mosaic couples. INTERVENTION(S): Assisted reproduction with preimplantation genetic testing (PGT). MAIN OUTCOME MEASURE(S): Karyotypes, embryo-related chromosomal abnormalities, and PGT results. RESULT(S): A total of 209 embryos were obtained from 68 mosaic couples, and 153 (73.21%) of 209 of the total embryos were obtained from 55 mosaic couples with abnormal sex chromosome numbers. Of these 153 embryos, 2 (1.31%) had an abnormal copy number of X chromosome, 1 had mosaicism with 46,XN,+X(mosaic, 40%), 1 (0.65%) had an extra Y chromosome, 3 (1.96%) exhibited both X chromosomal and autosomal abnormalities, and 4 (2.61%) exhibited de novo X chromosome structural abnormalities. A total of 56 (26.79%) of 209 embryos were obtained from mosaic couples (n = 13) with abnormal autosomal structures. Notably, of these 56 embryos, 5 (8.93%) had a 16q21-q24.3 copy number abnormality related to the parental karyotype, with a fragile site at 16q22; 5 (7.14%) exhibited 46,XX,dup(8p23.1-8p11.21) and 46,XY,del(8p22-8p11.21), which were related to the parental karyotype; and 10 (17.86%) were de novo chromosome abnormalities. CONCLUSION(S): Our data demonstrate that the risk of embryo-related chromosome abnormalities in mosaic patients with abnormal sex chromosomes is very low. Therefore, PGT may not need to be recommended for mosaic patients with abnormal copy numbers of sex chromosomes, especially for patients with financial difficulties. By contrast, the mosaic patients with structural abnormalities of autosomes may have a relatively high risk of abnormal embryos with an unbalanced segment of the involved chromosomes. Thus, PGT is highly recommended for mosaic patients with autosomal structure abnormalities, especially those with a fragile site at 16q22.

Effects of platforms, size filter cutoffs, and targeted regions of cytogenomic microarray on detection of copy number variants and uniparental disomy in prenatal diagnosis: Results from 5026 pregnancies.

OBJECTIVE: We evaluated the effects of platforms, size filter cutoffs, and targeted regions of cytogenomic microarray (CMA) on the detection of copy number variants (CNVs) and uniparental disomy (UPD) in prenatal diagnosis. METHODS: Five thousand twenty-six consecutive prenatal specimens (>98% high-risk pregnancy) were studied by high-resolution CMA, with cutoffs of 50 kb for losses and 200 kb for gains in nontargeted regions and 20 kb for losses and 100 kb for gains in targeted regions. We assessed actual detection rates using the current assay as well as hypothetical detection rates using platforms with the same or lower resolution and smaller or larger cutoffs. RESULTS: The detection rate of our current assay was 11.2% (562 of 5026), including abnormal findings in 543 cases and likely pathogenic variants in 19. The hypothetical decrease in the overall detection of variants (excluding likely benign) and UPD ranged from 3.8% to 23.0%. For the subgroup of pathogenic and likely pathogenic CNVs < 1 Mb, the decrease of detection ranged from 2.7% to 24.3%. CONCLUSIONS: These findings underscore the significant effects of chosen CMA platform, as well as size filter cutoffs and targeted regions used in data analysis, on detection of CNVs and UPDs in a cohort of prenatal cases.

The cytogenetic constitution of human blastocysts: insights from comprehensive chromosome screening strategies.

BACKGROUND: Embryos that are able to form blastocysts have succeeded in activating their genome and differentiating into two cell types-an external layer of trophectoderm cells, which will go on to form extra-embryonic tissues such as the placenta, and the inner cell mass, which will give rise to the embryo proper. Culturing embryos to the blastocyst stage has become an increasingly popular IVF practice over the past decade. Additionally, it has been proposed that the identification and transfer of euploid blastocysts could significantly improve IVF outcomes. Toward this end, comprehensive molecular cytogenetic methods have been developed. The application of such methods in both clinical and research contexts has yielded cytogenetic data from large numbers of blastocysts. Questions have been raised concerning the implantation potential of blastocysts diagnosed 'euploid' or 'aneuploid', and there has been particular debate over the detection and viability of embryos categorized as 'mosaic'-composed of a mixture of normal and aneuploid cells. OBJECTIVE AND RATIONALE: This review aims to summarize data from studies using comprehensive molecular cytogenetic methods to examine blastocyst-stage embryos, describing current knowledge related to rates of euploidy, uniform aneuploidy and mosaicism. Issues associated with the developmental capacity of blastocysts of different cytogenetic constitutions will also be addressed. Guidelines on the clinical management of blastocysts with varying chromosome complements will be considered. SEARCH METHODS: Rates of euploidy, uniform aneuploidy (in which all cells have the same abnormal karyotype) and mosaicism were determined via a thorough literature search (PubMed). The keywords used in the search were as follows: preimplantation embryo development, blastocyst stage, embryonic aneuploidy, meiotic chromosome malsegregation, post-zygotic chromosome malsegregation, comprehensive chromosome screening, array comparative genomic hybridization, single-nucleotide polymorphism array, next-generation sequencing, embryo mosaicism and implantation of mosaic embryos. Relevant articles written in English and published up to March 2018 were reviewed. OUTCOMES: Different types of aneuploidy, including some complex forms, are capable of persisting to the blastocyst stage. As expected, euploidy rates decreased with advancing female age, whereas uniform aneuploidy increased. Analysis of multiple cells from individual blastocysts revealed that most of those classified 'abnormal' contained no euploid cells (due to meiotic errors arising in the gametes and therefore present in every cell), some having additional mosaic (post-fertilization, mitotic) errors. Blastocysts with a mix of normal and aneuploid cells were observed less frequently than other classes of embryo. The transfer of embryos with diploid-aneuploid mosaic biopsy specimens is reportedly associated with higher miscarriage and lower implantation rates, compared to embryos in which only euploid cells are detected. WIDER IMPLICATIONS: Detailed investigations into the chromosome constitution of human blastocysts suggest that a significant proportion is euploid in every cell, although the exact fraction is strongly influenced by female age. These findings do not support the notion that mosaic chromosome abnormalities are a natural part of embryo development. Mosaic aneuploidies, arising post-zygotically, were detected by various different comprehensive molecular cytogenetic methods, suggesting that the majority of these represent genuine findings. However, it remains possible that certain comprehensive molecular cytogenetic methods may carry a risk of mosaicism being incorrectly assigned, in a minority of samples, as a result of technical artifact. This may be a consequence of degraded DNA in the trophectoderm biopsy or other technical issues. According to published studies, blastocysts considered to have uniform aneuploidy and, to a lesser extent, those with mosaic abnormalities were associated with poorer clinical outcomes in comparison with euploid embryos.

Treatment With JAK Inhibitors in Myelofibrosis Patients Nullifies the Prognostic Impact of Unfavorable Cytogenetics.

INTRODUCTION: In the era before Janus kinase (JAK) inhibitors, cytogenetic information was used to predict survival in myelofibrosis patients. However, the prognostic value of cytogenetics in the setting of JAK inhibitor therapy remains unknown. PATIENTS AND METHODS: We performed a retrospective analysis of 180 patients with bone marrow biopsy-proven myelofibrosis from 3 US academic medical centers. We fit Cox proportional hazards models for overall survival and transformation-free survival on the bases of 3 factors: JAK inhibitor therapy as a time-dependent covariate, dichotomized cytogenetic status (favorable vs. unfavorable), and statistical interaction between the two. The median follow-up time was 37.1 months. RESULTS: Among patients treated with best available therapy, unfavorable cytogenetic status was associated with decreased survival (hazard ratio = 2.31; P = .025). At initiation of JAK inhibitor therapy, unfavorable cytogenetics was (nonsignificantly) associated with increased survival compared to favorable cytogenetics (hazard ratio = 0.292; P = .172). The ratio of hazard ratios was 0.126 (P = .034). These findings were similar after adjusting for standard clinical prognostic factors as well as when measured against transformation-free survival. CONCLUSION: The initiation of JAK inhibitor therapy appears to change the association between cytogenetics and overall survival. There was little difference in survival between treatment types in patients with favorable cytogenetics. However, the use of JAK inhibitor therapy among patients with unfavorable cytogenetics was not associated with worse survival compared to favorable cytogenetics. Our analyses suggest that initiation of JAK inhibitor therapy nullifies the negative prognostic implication of unfavorable cytogenetics established in the pre-JAK inhibitor therapy era.

Women's preference for non-invasive prenatal DNA testing versus chromosomal microarray after screening for Down syndrome: a prospective study.

OBJECTIVE: To examine preferences for follow-up testing in women screened with high or intermediate risk for Down syndrome in the first or second trimester. DESIGN: Prospective cohort study. SETTING: Three public hospitals in Hong Kong, China. SAMPLE: Women with pregnancies termed as high risk (≥1:250; HR) or intermediate risk (1:251-1200; IR) for Down syndrome. METHODS: Women with pregnancies screened as HR were offered the choices of: (1) an invasive test plus chromosomal microarray (CMA) to obtain more detailed fetal genetic information; (2) non-invasive cell-free prenatal DNA screening (NIPT) to detect trisomies 13, 18 and 21, and to avoid procedure-related miscarriage; and (3) to decline any further testing. Women received standardised counselling informing them that the reporting times were identical, the procedure miscarriage risk was 0.1-0.2% and that there was no charge for screening. Women with IR pregnancies (1:251-1200) were offered NIPT as a secondary screening test. MAIN OUTCOME MEASURES: Uptake rate for NIPT. RESULTS: Three hundred and forty-seven women had pregnancies deemed as HR; 344 (99.1%) women opted for follow-up testing, 216 (62.2%) of whom chose NIPT. Five hundred and seven of 614 women (82.6%) with IR risk chose NIPT. Seven (21%) of 34 women with nuchal translucency ≥3.5 mm opted for NIPT. CONCLUSION: In a setting where reporting times are similar and there is no cost difference between options, approximately 60% of women with pregnancies classed as HR would opt for NIPT, offering simple but limited aneuploidy assessment, over a diagnostic procedure with comprehensive and more detailed assessment. TWEETABLE ABSTRACT: 60% of pregnant Chinese women prefer NIPT over CMA when screened as high risk for Down syndrome.

Cytogenetic analysis in fetuses with late onset abnormal sonographic findings.

OBJECTIVE: To determine the rate of chromosomal cytogenetic abnormalities in fetuses with late onset abnormal sonographic findings. DESIGN: Retrospective cohort of women who underwent amniocentesis at or beyond 23 weeks of gestation, for fetal karyotype and chromosomal microarray analysis, indicated due to late onset abnormal sonographic findings. RESULTS: All 103 fetuses had a normal karyotype. Ninety-five women also had chromosomal microarray analysis (CMA) performed. The detection rate of abnormal CMA (5/95, 5.3%) was similar to that of women who underwent amniocentesis due to abnormal early onset ultrasound findings detected at routine prenatal screening tests during the first or early second trimester (7.3%, P=0.46) and significantly higher than that for women who underwent amniocentesis and CMA upon request, without a medical indication for CMA (0.99%, P<0.0001). CONCLUSIONS: Late onset sonographic findings are an indication for amniocentesis, and if performed, CMA should be applied to evaluate fetuses with late onset abnormal sonographic findings.

Prenatal diagnosis of Down syndrome: A 13-year retrospective study.

OBJECTIVE: The aim of this study is to summarize the experience on prenatal diagnosis of Down syndrome. MATERIALS AND METHODS: The study includes a retrospective data analysis of 157 prenatally detected cases of Down syndrome, routinely diagnosed among 6448 prenatal investigations performed during a 13-year period (2002-2014) in a single tertiary center. RESULTS: The prevalence of diagnosed Down syndrome cases was 2.4%. Maternal age alone was indication for prenatal diagnosis in 47 cases (45.2%), increased first-/second-trimester biochemical screening test in 34 cases (21.7%), abnormal ultrasound examination in 69 cases (43.9%), positive familial history for chromosomal abnormalities in four cases, and high risk for trisomy 21 revealed by cell-free DNA testing in three cases. Ultrasound anomalies were present in total of 94 fetuses (59.8%). The most common abnormality was cystic hygroma found in 46 cases (29.3%). A regular form of Down syndrome (trisomy 21) was found in 147 cases (93.6%), Robertsonian translocation in six cases (3.8%), and mosaic form in four cases (2.6%). CONCLUSION: In prenatal diagnosis of Down syndrome noninvasive screening methods are important for estimation of individual risks, in both, young population of woman and older mothers, while conventional and molecular cytogenetic methods are essential for definite diagnosis and proper genetic counseling.

Investigation of the influence of calibration practices on cytogenetic laboratory performance for dose estimation.

PURPOSE: In the frame of the QA program of RENEB, an inter-laboratory comparison (ILC) of calibration sources used in biological dosimetry was achieved to investigate the influence of calibration practices and protocols on the results of the dose estimation performance as a first step to harmonization and standardization of dosimetry and irradiation practices in the European biological dosimetry network. MATERIALS AND METHODS: Delivered doses by irradiation facilities used by RENEB partners were determined with EPR/alanine dosimetry system. Dosimeters were irradiated in the same conditions as blood samples. A short survey was also performed to collect the information needed for the data analysis and evaluate the diversity of practices. RESULTS: For most of partners the deviation of delivered dose from the targeted dose remains below 10%. Deviations larger than 10% were observed for five facilities out of 21. Origins of the largest discrepancies were identified. Correction actions were evaluated as satisfactory. The re-evaluation of some ILC results for the fluorescence in situ hybridization (FISH) and premature chromosome condensation (PCC) assays has been performed leading to an improvement of the overall performances. CONCLUSIONS: This work has shown the importance of dosimetry in radiobiology studies and the needs of harmonization, standardization in irradiation and dosimetry practices and educational training for biologists using ionizing radiation.

[Hygienic environmental assessment in the oil-and-gas bearing area on the base of cytogenetical and molecular-genetic methods].

The study have been conducted in settlements located near oilfields of the Nizhnevartovsk area, the Khanty-Mansi autonomous district (Russian Federation). There were examined 802 persons aged of from 18 to 56 years not proximately employed in processes of the oil extraction. Control group was consisted of329 residents of the north of Tomsk Region living in the area without any polluting environment industry. By using such methods of analysis as micronucleus test in human buccal cells, the xenobiotic biotransformation of both GSTM1 and GSTT1 gene polymorphism, as well as the assessment of oil contamination of local drinking water there was executed the hygienic assessment of ecology in the settlements located near oil fields. The elevated rate of cytogenetic disorders was established to be observed most of all in the residents of this region, as well as in persons recently moved to this area. Most significant deviations from the control according to the micronucleus test were detected in individuals with the GSTM1 (0) /GSTT1(0) genotype. In the control group no such consistent pattern was seen.

Cytogenetic place in managing myelodysplastic syndromes: an update by the Groupe francophone de cytogénétique hématologique (GFCH).

The myelodysplastic syndromes (MDS) are preleukemic diseases of elderly patients characterized by defective maturation of clonal hematopoietic progenitor cells resulting in peripheral blood cytopenias. Clonal chromosomal abnormalities are heterogeneous and can be detected in less than 50% of patients with de novo MDS and more frequently in secondary MDS (up to 80%). The karyotype plays an important role in the pathogenesis, diagnosis, and prognosis to evaluate the risk of leukemic transformation and, more recently, in treatment allocation. The gold standard for cytogenetic diagnosis in MDS is conventional chromosome banding analyses of bone marrow metaphases. The most frequent abnormalities are deletions and losses of chromosomes 5 (-5/5q-) and 7 (-7/7q-) and various isolated or combined abnormalities. Fluorescent in situ hybridization and array comparative genomic hybridization can reveal cryptic genetic abnormalities but are not recommended in routine diagnosis. New techniques including next generation sequencing revealed somatic driver mutations especially those affecting genes involved in RNA splicing or those harboring important prognostic value (TP53, ASXL1…) with potential applications in clinical practice in the future.

[Cytogenetic status of children in the hygienic assessment of the air pollution by odorous substances].

For the first time the impact of odorous emissions from the enterprise for the production of chewing gum on the cytogenetic status of children, residing in the distance of 0,9 and 6 km, was studied. Specific weak mint and fruity odour in the air in the placement of the enterprise may be related to the presence of menthol, menthone, pinene, limonene, ethyl acetate and other compounds containing in the emissions. There were no differences in cytogenetic status of children in both groups (by frequency of micronuclei, protrusions, binucleated cells, apoptosis).

[Cytogenetic status of the residents of the Gydansky Peninsula (Gydan)].

The relevance of the study on the Gydansky Peninsula lies in poor knowledge and inaccessibility of the territory, planned intensive industrial development of the Gydansky Peninsula, in 2011 there were received licenses for the exploration of license areas at the peninsula up to 2031. Industrial development will inevitably lead to certain environmental shifts, emission of the harmful substances into biosphere, the accumulation of anthropogenic pollutants in soil and water sources. The proposed development of the territory of the Peninsula Gydan sets the task of assessment of the impact of gas and oil production in conditions of the far North on health, as well indigenous persons as employees recruited to this of the region. One of the informative approaches to the assessment of population health is the assessment of the cytogenetic status with the use of noninvasive analysis of buccal epithelium. The aim of the study is to determine the cytogenetic status of the inhabitants of the village of Antipayuta of the Yamal-Nenets Autonomous Okrug for the assessment of the impact of environmental factors on the health of the population at the present stage of the industrial development of the territory. Samples of buccal epithelium of 81 alien and indigenous people of the Yamal-Nenets Autonomous district were the object of the investigation. There was performed the analysis of indices of cells of buccal epithelium of the residents living in the village in comparison with the control group. The analysis of samples was performed on a Nikon Eclipse E100 microscope. For the assessment of the cytogenetic status of the individual there was used the proposed by Sycheva L. P. (2012-Index of accumulation of cytogenetic damages (Iac). It is shown that the frequency of occurrence of micronucleus and nuclear protrusions does not exceed the performance of the control group. The index of accumulation of cytogenetic damage for the population of the village is 0.78±0.07% and corresponds to a low level. The analysis of indices of buccal epithelial cells of residents living in rural areas was performed in the comparison with the control group The prevalence rate of cells with micronuclei and protrusions were shown to account of 14.6% andfail to exceed indices in the control group. Accumulation index of cytogenetic damages for the village population is 0.78 ± 0.07 % and corresponds to the low level. The amount of cells with micronuclei and protrusions in the current study is by 14.6% lower than the average of the control group. The intensity of proliferative processes and apoptosis in the comparison groups occurs evenly.

Fenotipos neurológicos en pacientes estudiados con citogenética en el Hospital de Puerto Montt / Neurological phenotypes in cytogenic study from Puerto Montt Hospital patients

El examen citogenético, es una herramienta importante para confirmar el diagnóstico, manejo y consejo genético. El objetivo es analizar las características del fenotipo neuroconductual, protocolizar y orientar en la eficaz solicitud del estudio citogenético. Se revisaron las fichas clínicas de los pacientes controlados del policlínico de Neuropediatría del Hospital de Puerto Montt, con cariograma anormal entre los años 2007 y 2012. De 248 pacientes, 12% se identificó una alteración; 58% aberraciones estructurales, 20% aneuploidías, y 20% alteraciones genético - moleculares. Los elementos clínicos que se encontraron fueron microcefalia 48%, retraso mental 67%, historia familiar 67%, hipotonía 70%, convulsiones 41%, alteraciones del SNC 37%.

Cytogenetic examination is an important tool for confirming diagnosis, case management and genetic counseling. The aim is to analyze the characteristics of neurobehavioral phenotypes, formalize and guide the effective application of cytogenetics. The medical records of patients with abnormal karyotype seen between 2007 and 2012 at the Hospital of Puerto Montt's neuropaediatric outpatient clinic were reviewed. Of 248 patients, in 12% an alteration was identified; 58% structural aberrations, 20% aneuploidy, and 20% genetic-molecular alterations. The clinical elements found were 48% microcephaly, 67% mental retardation, 67% family history, 70% hypotonia, 41% seizures, 37% CNS disorders.

Emerging issues in invasive prenatal diagnosis: Safety and competency in the post-NIPT era.

BACKGROUND: Numbers of invasive prenatal procedures are declining in response to improved aneuploidy screening methods. OBJECTIVE: To assess current practice and attitudes of clinicians performing invasive prenatal diagnosis in regard to patient consent and safety, maintaining procedural competence and uptake of chromosomal microarrays (CMAs). METHODS: Anonymous online survey of the Australian Association of Obstetrical and Gynaecological Ultrasonologists conducted in March 2015. RESULTS: The survey had a 45% response rate with 59 respondents from Australia. Of these, 34 were subspecialists in maternal fetal medicine or obstetric and gynaecological ultrasound. Fifty-six (95%) currently performed amniocentesis or chorionic villus sampling. Of these, 14 (25%) performed <25 procedures and 8 (14%) performed >150 annually, with most respondents (60%) proposing 10-25 amniocenteses/year as adequate activity to maintain their skills. The majority neither expected referrers to provide results of hepatitis B and HIV serology, nor followed up missing results. There was uncertainty regarding the procedure-related vertical transmission risk of HBV in women with high viral load, with most respondents stating they were either unsure of the risk (22%) or that the risk was unknown (30%). Fifty per cent of practitioners routinely ordered CMA after invasive testing; all recommended CMA following a diagnosis of structural abnormality. CONCLUSIONS: In a period of declining testing, many Australian specialists are performing <25 procedures annually. Consideration of the potential risks of bloodborne viruses is limited. CMAs are rapidly being incorporated into clinical practice. These data have implications for patient consent and safety, and workforce training and practice.