Frequency Of Chromosomal Abnormalities Research Articles

Investigates the genetic types of acute lymphoblastic leukemia in full remission Indonesian patients: a cross-sectional analysis

Acute lymphoblastic leukemia (ALL) is most common in children, especially those aged 1–4 years old, and the second most common acute leukemia in adults. The updated International Consensus Classification (ICC) of B-acute lymphoblastic leukemia (B-ALL) and T-acute lymphoblastic leukemia (T-ALL) includes recent clinical, cytogenetic, and molecular data. Transcriptome sequencing (RNA-seq) was performed on 200 bone marrow specimens using TruSeq library preparation and HiSeq 2000/2500 or NovaSeq 6000 sequencers (Illumina). The purpose of this study was to define the frequency of chromosomal abnormalities of ALL patients in adults and children in Indonesian patients after full remission for international collaboration has improved and advanced the diagnosis and treatment of ALL in Indonesia. Our resulting data showed that the most common structural abnormality was t(9;22) in 15% of the patients. The frequency of genetic abnormalities was 69 % and 60% for numerical and/or structural in the B-ALL and T-ALL patients, respectively. The adults had a higher incidence of t(9;22) and a lower incidence of hyperdiploid than children. In conclusion: The results of this study molecular subtypes differ strikingly in their responses to treatment that needs more assessment.

Cytotoxic and Mitodepressive Effect of Insecticide Profenofos on Root Meristem of Allium cepa L.

A study was performed for cytotoxic and mitodepressive effect of pesticide through root meristem of Allium cepa L. Various concentration (0.2%, 0.4%, 0.6%, 0.8% and 1.0%) of organophosphate insecticide profenofos for 24, 48 and 72 hrs time points exposed to A. cepa. The cytotoxic and genotoxic effects were evident through inhibited mitotic division and increased percentage of chromosome abnormality. Dose and duration dependent statistically significant reduction in mitotic index was recorded. The minimum mitotic index (3.94%) was estimated at 1.0% for 72 hrs. Cytogenetic endpoints like mitotic depression, relative abnormality rate and frequency of chromosomal abnormality were found to be increased when compared to control plants. Various chromosomal aberration like stickiness, laggard, bridge, fragmentation and micronuclei were also observed. Cytogenetic biomarker is very efficient and non-expensive tool to screening and biomonitoring cytotoxicity at chromosomal and DNA level.

Toxicity Assessment of a No-Pain Pharmacopuncture Extract Using a Standard Battery of In Vitro Chromosome Aberration Tests.

Genotoxicity is evaluated through a chromosomal aberration test using cultured mammalian cells to determine the toxicity of no-pain pharmacopuncture (NPP), which has recently been used to treat musculoskeletal pain disorders in Korean medical clinical practice. An initial test was performed to determine the dosage range of the NPP, followed by the main test. In this study, NPP doses of 10.0, 5.0, and 2.5%, and negative and positive controls were tested. An in vitro chromosome aberration test was performed using Chinese hamster lung cells under short-term treatment with or without metabolic activation and under continuous treatment without metabolic activation. Compared with the saline negative control group, NPP did not significantly increase the frequency of chromosomal abnormalities in Chinese hamster lung cells, regardless of the presence or absence of metabolic activation. Additionally, the number of cells with structural chromosomal abnormalities was significantly higher in the positive control group than that in the negative control group that received saline. Based on the above results, the chromosomal abnormality-producing effect of NPP was determined to be negative under these test conditions.

Experience of copy number variation sequencing applied in spontaneous abortion

PurposeWe evaluated the value of copy number variation sequencing (CNV-seq) and quantitative fluorescence (QF)-PCR for analyzing chromosomal abnormalities (CA) in spontaneous abortion specimens.MethodsA total of 650 products of conception (POCs) were collected from spontaneous abortion between April 2018 and May 2020. CNV-seq and QF-PCR were performed to determine the characteristics and frequencies of copy number variants (CNVs) with clinical significance. The clinical features of the patients were recorded.ResultsClinically significant chromosomal abnormalities were identified in 355 (54.6%) POCs, of which 217 (33.4%) were autosomal trisomies, 42(6.5%) were chromosomal monosomies and 40 (6.2%) were pathogenic CNVs (pCNVs). Chromosomal trisomy occurs mainly on chromosomes 15, 16, 18, 21and 22. Monosomy X was not associated with the maternal or gestational age. The frequency of chromosomal abnormalities in miscarriages from women with a normal live birth history was 55.3%; it was 54.4% from women without a normal live birth history (P > 0.05). There were no significant differences among women without, with 1, and with ≥ 2 previous miscarriages regarding the rate of chromosomal abnormalities (P > 0.05); CNVs were less frequently detected in women with advanced maternal age than in women aged ≤ 29 and 30–34 years (P < 0.05).ConclusionChromosomal abnormalities are the most common cause of pregnancy loss, and maternal and gestational ages are strongly associated with fetal autosomal trisomy aberrations. Embryo chromosomal examination is recommended regardless of the gestational age, modes of conception or previous abortion status.

CLINICAL, ULTRASOUND AND CYTOGENETIC CHARACTERISTICS OF FETUSES WITH INCREASED NUCHAL TRANSLUCENCY THICKNESS IN THE FIRST TRIMESTER OF PREGNANCY

Background: Improving programs for early prenatal detection of congenital malformations remains a relevant scientific and practical problem. The prevalence of congenital anomalies in Ukraine is 23.7:1000 among live-born babies, and there is no significant decrease in it. The aim of this study was to compare clinical, ultrasound and cytogenetic data in swollen fetuses with increased nuchal translucency (NT) thicknesses from the group of pregnant women in the first trimester at high genetic risk to optimize the algorithm of prenatal diagnostics.&#x0D; Materials and Methods: Clinical examinations, ultrasound diagnostics, invasive methods of prenatal diagnostics (chorion biopsy, amniocentesis), genetic testing techniques, such as karyotyping and FISH, genetic counseling and statistical analysis were carried out. The results of complex examinations of 127 fetuses with an increased NT thickness from the group of pregnant women were analyzed. Fetuses were divided into two groups with an NT thickness of 2.5–3.5 mm (group 1) (38 cases) and with an NT above 3.5 mm (group 2)(89 cases).&#x0D; Results: Among pregnancies with fetuses with an increased NT thickness, there were 65.4% cases of adverse outcomes with chromosomal pathology (69.9%), congenital malformations of non-chromosomal etiology (25.3%) and pregnancy loss (4.8%). The frequency of chromosomal abnormalities in fetuses of group 1 was 55.3% and 41.6% in group 2. Congenital malformations of various systems and organs in fetuses, the most frequent of which were cardiac defects, were diagnosed. The ratio of congenital heart defects in the fetuses of groups 1 and 2 was 23.7% and 43.8%, respectively (p=0.03; OR=0.40).&#x0D; Conclusion: There is no significant difference between the frequency of chromosomal abnormalities in the fetuses of group 1 compared to group 2, which indicates a high informative value of an increased NT thickness, including the thickness of 2.5–3.5 mm in fetuses in the first trimester as a marker of chromosomal pathology. A significantly higher incidence of congenital malformations of non-chromosomal etiology was found in fetuses with venous duct pathology and NT thickness over 3.5 mm compared to fetuses with the same pathology and NT thickness of 2.5–3.5 mm. Proposed changes to the management algorithm for pregnant women with swollen fetuses include mandatory congenital heart defects screening in the first trimester.

Evaluation of chromosomal abnormalities in the postnatal cohort: A single-center study on 14,242 patients.

Chromosomal analysis is a laboratory technique used to examine the chromosomes of an individual, offering insights into chromosome numbers, structures, and arrangements to diagnose and comprehend genetic diseases. This retrospective study provides a comprehensive understanding of the distribution by indications in a large cohort of 14,242 patients and the frequency of chromosomal abnormalities in different clinical populations. The study examined various indications for karyotype evaluation, with recurrent pregnancy loss being the most common indication, followed by intellectual disability, dysmorphic features, congenital anomalies, and developmental delay. The overall chromosomal abnormality rate was found to be 5.4%, with numerical abnormalities accounting for the majority of cases (61.7%). Trisomies, particularly trisomy 21, were the most frequent numerical abnormalities. In terms of structural abnormalities, inversions and translocations were the most commonly identified. The rates of chromosomal anomalies varied in specific indications such as amenorrhea, disorders of sex development, and Turner syndrome. The study also highlighted significant differences between males and females in the presence of chromosomal abnormalities across certain indications. Males exhibited a higher incidence of chromosomal abnormalities in cases of Down syndrome and infertility, whereas females showed higher abnormalities in terms of recurrent pregnancy loss. While this study provides valuable insights into the frequency and distribution of chromosomal abnormalities, it has limitations, including its retrospective design and reliance on data from a single medical genetics department. Nevertheless, the findings emphasize the importance of karyotype analysis in diagnosing chromosomal disorders and providing appropriate management, while also pointing to potential gender-related variations in chromosomal abnormalities that warrant further investigation.

Chromosomal Abnormalities in Early Pregnancy Losses: A Study of 900 Samples.

Chromosomal abnormalities are the most common causes of early pregnancy losses (EPLs). In this study, we aimed to evaluate the incidence and spectrum of chromosomal abnormalities in EPLs and correlate them with different clinical characteristics. We performed Quantitative Fluorescent PCR (QF-PCR), followed by subtelomeric Multiplex Ligation Probe Amplification (MLPA) analysis to detect chromosomal abnormalities in 900 products of conceptions (POCs) from EPLs collected over a period of 10 years. Chromosomal abnormalities were present in 56.25% of uncontaminated EPLs, with significantly higher incidence in women ≥36 years (71.37%, p<0.0001) in comparison to women ≤30 years of age (43.40%). Trisomies were also more common in women ≥36 years (79.68%, p<0.0001) than in those ≤30 years of age (48.70%). In contrast, triploidy and monosomies were more prevalent in women ≤30 years of age (26.09%, p<0.0001 and 16.52%, p=0.0066 respectively) than in women ≥36 years of age (6.42% and 6.42% respectively). Trisomy 16 was more common in women ≤30 (39.29%, p=0.0009) than in those ≥36 years of age (16.78%), while trisomy 22 was predominant among women ≥36 (23.49%, p=0.013), and was not present in the group of women ≤30 years of age. The frequency of chromosomal abnormalities in POCs from women with sporadic (61.19%) was higher than in those with recurrent EPLs (55.21%). This difference, however, was not statistically significant (p=0.164). Although some differences in the chromosomal aneuploidy rates among women with different ABO blood groups, as well as among 6-8 and 9-11 gestational week EPLs were observed, further larger studies are required to confirm these findings. In conclusion, our study enriches the knowledge about chromosomal abnormalities as a cause of EPLs and confirms the higher incidence of foetal chromosomal abnormalities in EPLs in women of older reproductive age. Furthermore, it shows that using QF-PCR and MLPA methodologies, a high detection rate of chromosomal abnormalities in EPLs can be reached.

Prevalence and patterns of chromosomal abnormalities in patients suspected of genetic disorders: insights from a study in Ouagadougou, Burkina Faso.

Chromosomal abnormalities contribute significantly to human morbidity and mortality, leading to various pathologies. This study aimed to assess the prevalence of chromosomal abnormalities among patients suspected of genetic disorders in Ouagadougou, Burkina Faso. A descriptive cross-sectional study was conducted from January 1, 2018, to July 16, 2021, involving patients from different university hospitals in Ouagadougou. Blood samples were collected at Hôpital Saint Camille de Ouagadougou (HOSCO) and sent to the Cerba laboratory in France for cytogenetic analysis. A total of 61 cases with suspected genetic disorders were referred for cytogenetic examination. The average age of the patients was 26.81 years ± 18.92, ranging from 1 month to 68 years. Among the cases, 37 (60.65%) exhibited chromosomal abnormalities. Structural abnormalities were the most prevalent (78.38%), while number anomalies accounted for 21.62% of the cases. Chronic myeloid leukemia was detected in 59.45% of cases, followed by free and homogeneous trisomy 21 (18.91%) and sexual inversion (8.10%). Additionally, one case each of Turner syndrome and Klinefelter syndrome were identified. This this study revealed a high frequency of chromosomal abnormalities, with a predominance of structural abnormalities, among patients suspected of genetic disorders in Ouagadougou. The findings emphasize the significance of genetic evaluation and counseling services in the region, particularly for autosomal abnormalities.

CHALLENGES FOR CHROMOSOME ANALYSIS IN PREGNANCY LOSS: LESSONS LEARNED FROM 1208 SAMPLE EXPERIENCE

Objective: Previous studies have shown that half of the spontaneous abortions were associated with fetal chromosomal abnormalities, however it is not always possible to reveal the reasons of pregnancy loss. The aim of the current study was to investigate the frequency of chromosome abnormalities and culture failure rates of pregnancy loss and compare the results with similar studies in the literature.&#x0D; &#x0D; Material and Methods: The karyotype analysis results of 1208 abortion materials which were obtained from long-term cultures of chorionic villus samples of the patients who were admitted to the Haseki Training and Research Hospital Genetic Diagnosis Center between August 2016 and February 2021, were evaluated retrospectively.&#x0D; &#x0D; Results: No results were obtained due to culture failure in approximately half of the materials. Numerical anomalies were observed in 87% (116) of abnormal karyotypes that consist of trisomy, monosomy X and triploidy. Trisomies were the most common anomaly. While the frequency of trisomy was significantly higher in the older age group (≥35 years) (p=0.001), the frequency of monosomy X and triploidy were higher in the younger age group. Chromosomal changes whose frequencies were not affected by maternal age were structural chromosomal abnormalities and tetraploidies.&#x0D; &#x0D; Conclusion: Since the developing new Technologies are still not affordable enough and their widespread use is limited. As a result, current approaches have indicated that chromosome analysis is still a necessary and useful method. It is thought that detecting the chromosomal anomaly that led to abortion facilitates multidisciplinary patient management and enables to provide more accurate and comprehensive genetic counseling. In cases where the chromosome analysis test is not informative, the application of DNA-based tests such as Quantitative Fluorescence PCR (QF-PCR) and molecular karyotyping may help the diagnosis.

Modulation of phytotoxic and cytogenetic effects of cadmium by humic acid: Findings from a short-term plant-based bioassay.

The study of the modulation of the toxicity of heavy metals by coexisting chemicals in the environment is vital for realistic ecological risk assessment. Our study was aimed at determining possible toxicity modulations of Cd by humic acid (HA) using the Allium cepa test system. A. cepa bulbs were exposed to Cd (1 and 5 mg/L) and HA (10 mg/L) individually or in mixtures. The root lengths of the bulbs and cytogenetic endpoints in root meristematic cells, including the mitotic index (MI), nuclear abnormalities (NAs), and chromosomal abnormalities (CAs), were determined. The results revealed that the MIs of A. cepa co-exposed to HA and Cd were significantly recovered by >15% compared with those of A. cepa subjected to Cd-only treatments, and this response was more sensitive than the phytotoxic response (root length). Furthermore, the burden of NAs was significantly decreased in the co-exposed bulbs by >20% compared with bulbs with Cd-only treatments. The frequencies of CAs were also reduced in the bulbs co-exposed to HA and 1 and 5 mg/L Cd by >15 and >25%, respectively, compared with bulbs receiving Cd-only treatments. Therefore, our findings indicated that HA plays a significant protective role in Cd toxicity in A. cepa.

DNA fragmentation and multifaceted toxicity induced by high-dose vanadium exposure determined by the bioindicator Allium test

In this study, the toxicity of vanadium (VCI3) in Allium cepa L. was studied. Germination-related parameters, mitotic index (MI), catalase (CAT) activity, chromosomal abnormalities (CAs), malondialdehyde (MDA) level, micronucleus (MN) frequency and superoxide dismutase (SOD) activity were investigated. The effects of VCI3 exposure on the DNA of meristem cells were investigated with the help of comet assay, and the relationships between physiological, cytogenetic and biochemical parameters were revealed by correlation and PCA analyses. A. cepa bulbs were germinated with different concentrations of VCI3 for 72 h. As a result, the maximum germination (100%), root elongation (10.4 cm) and weight gain (6.85 g) were determined in the control. VCI3 treatment caused significant decreases in all tested germination-related parameters compared to the control. The highest percentage of MI (8.62%) was also observed in the control. No CAs were found in the control, except for a few sticky chromosomes and unequal distribution of chromatin (p > 0.05). VCI3 treatment caused significant decreases in MI and increases in the frequencies of CAs and MN, depending on the dose. Similarly, the comet assay showed that DNA damage scores increased with increasing VCI3 doses. The lowest root MDA (6.50 µM/g) level and SOD (36.7 U/mg) and CAT (0.82 OD240nmmin/g) activities were also measured in the control. VCI3 treatment caused significant increases in root MDA levels and antioxidant enzyme activities. Besides, VCI3 treatment induced anatomical damages such as flattened cell nucleus, epidermis cell damage, binuclear cell, thickening in the cortex cell wall, giant cell nucleus, damages in cortex cell and unclear vascular tissue. All examined parameters showed significant negative or positive correlations with each other. PCA analysis confirmed the relations of investigated parameters and VCI3 exposure.

Comparative cytogenetics of anembryonic pregnancies and missed abortions in human.

Miscarriage is an important problem in human reproduction, affecting 10-15 % of clinically recognized pregnancies. The cases of embryonic death can be divided into missed abortion (MA), for which the ultrasound sign of the embryo death is the absence of cardiac activity, and anembryonic pregnancy (AP) without an embryo in the gestational sac. The aim of this study was to compare the frequency of chromosomal abnormalities in extraembryonic tissues detected by conventional cytogenetic analysis of spontaneous abortions depending on the presence or absence of an embryo. This is a retrospective study of 1551 spontaneous abortions analyzed using GTG-banding from 1990 to 2022 (266 cases of AP and 1285 cases of MA). A comparative analysis of the frequency of chromosomal abnormalities and the distribution of karyotype frequencies depending on the presence of an embryo in the gestational sac was carried out. Statistical analysis was performed using a chi-square test with a p <0.05 significance level. The total frequency of chromosomal abnormalities in the study was 53.6 % (832/1551). The proportion of abnormal karyotypes in the AP and MA groups did not differ significantly and amounted to 57.1 % (152/266) and 52.9 % (680/1285) for AP and MA, respectively (p = 0.209). Sex chromosome aneuploidies and triploidies were significantly less common in the AP group than in the MA group (2.3 % (6/266) vs 6.8 % (88/1285), p = 0.005 and 4.9 % (13/266) vs 8.9 % (114/1285), p = 0.031, respectively). Tetraploidies were registered more frequently in AP compared to MA (12.4 % (33/266) vs. 8.2 % (106/1285), p = 0.031). The sex ratio among abortions with a normal karyotype was 0.54 and 0.74 for AP and MA, respectively. Thus, although the frequencies of some types of chromosomal pathology differ between AP and MA, the total frequency of chromosomal abnormalities in AP is not increased compared to MA, which indicates the need to search for the causes of AP at other levels of the genome organization, including microstructural chromosomal rearrangements, monogenic mutations, imprinting disorders, and epigenetic abnormalities.

Fetal Tethered Spinal Cord: Diagnostic Features and Its Association with Congenital Anomalies

Objective We assessed the frequency and type of associated congenital anomalies encountered with fetal tethered spinal cord (TSC) determined prenatally. Method A retrospective review was conducted based on the associated fetal abnormalities following diagnosis of low-lying fetal conus medullaris during the prenatal ultrasound. Results Of the 26 fetuses with low-lying conus medullaris, four were solitary TSC and 22 had TSC combined with associated congenital malformations, including four cases with spina bifida occulta, four cases with spina bifida aperta, one case with severe hydrocephalus, and 13 cases with multisystem congenital malformations. Among all the 13 cases with combined multisystem congenital malformations, four cases had vertebral defects, anal anomalies, cardiac defects, trachea-esophageal fistula, renal anomalies, and limb anomalies (VACTERL) syndrome, two cases had combined kidney development abnormalities, one case had cloacal exstrophy (OEIS syndrome), and six cases had chromosomal abnormalities (one case of chromosome 7q deletion, two cases of trisomy 13 syndrome, one case of trisomy 18 syndrome, one case of trisomy 9 syndrome, and one case of chromosome 4p deletion). Conclusions Low-lying conus medullaris found during prenatal ultrasound examination were often associated with neural tube malformations or multi-systemic complex developmental malformations. The frequency of chromosomal abnormalities was 23.1%.

Chromosomal abnormalities detected by karyotyping among patients with secondary amenorrhea: a retrospective study

Chromosomal abnormalities (CAs) have been described in patients with secondary amenorrhea (SA). However, studies on this association are scarce. To evaluate the frequency and types of CAs detected by karyotyping in patients with SA. This retrospective study was performed in a reference clinical genetic service in South Brazil. Data were obtained from the medical records of patients with SA who were evaluated between 1975 and 2022. Fisher's bicaudate exact test and Student's t-test were used, and P < 0.05 was considered significant. Among 43 patients with SA, 14 (32.6%) had CAs, namely del (Xq) (n = 3), 45,X (n = 2), 46,X,r(X)/45,X (n = 2), 46,XX/45,X (n = 1), 46,X,i(q10)/45,X (n = 1), 47,XXX (n = 1), 46,XX/47,XXX (n = 1), 46,XX/47,XX,+mar (n = 1), 45,XX,trob(13;14)(q10;q10)/46,XXX,trob(13;14)(q10;q10) (n = 1), and 46,XX,t(2;21)(q23;q11.2) (n = 1). Additional findings were observed mostly among patients with CA compared with those without CA (P = 0.0021). No difference in the mean age was observed between the patients with SA with or without CAs (P = 0.268025). CAs are common among patients with SA, especially those with short stature and additional findings. They are predominantly structural, involve the X chromosome in a mosaic, and are compatible with the Turner syndrome. Patients with SA, even if isolated, may have CAs, particularly del (Xq) and triple X.

Prevalence of chromosomal abnormalities detected by fluorescence in situ hybridization in patients with chronic lymphocytic leukemia at Alexandria Main University Hospital

Abstract Background Understanding the genetic basis of chronic lymphocytic leukemia (CLL) will help in risk stratification and a better therapeutic strategy. We aimed to evaluate the frequency of chromosomal abnormalities using fluorescence in situ hybridization (FISH) panel at our institution compared with other studies. Patients and methods and results A CLL FISH panel that included P53/ATM Probe Combination and D13S319/13qter/12cen Deletion Enumeration Probe was analyzed in 100 newly diagnosed patients with CLL. TP53 deletion was the most prevalent aberration, which is in contrast with other Middle Eastern countries, where deletion 13q14 was the commonest aberration among patients. Conclusion The heterogeneity of CLL clinical course is possibly explained by underlying molecular factors that affect prognosis including data from FISH probes. It is proposed that these abnormalities should be investigated at the time of diagnosis to better understand the disease outcome and prognosis.

Cytogenetic Analysis of Sporadic First-Trimester Miscarriage Specimens Using Karyotyping and QF-PCR: A Retrospective Romanian Cohort Study.

It is well known that first-trimester miscarriages are associated with chromosome abnormalities, with numerical chromosome abnormalities being the ones most commonly detected. Conventional karyotyping is still considered the gold standard in the analysis of products of conception, despite the extended use of molecular genetic techniques. However, conventional karyotyping is a laborious and time-consuming method, with a limited resolution of 5-10 Mb and hampered by maternal cell contamination and culture failure. The aim of our study was to assess the type and frequency of chromosomal abnormalities detected by conventional karyotyping in specimens of sporadic first-trimester miscarriages in a Romanian cohort, using QF-PCR to exclude maternal cell contamination. Long-term cultures were established and standard protocols were applied for cell harvesting, slide preparation, and GTG banding. All samples with 46,XX karyotype were tested for maternal cell contamination by QF-PCR, comparing multiple microsatellite markers in maternal blood with cell culture and tissue samples. Out of the initial 311 specimens collected from patients with sporadic first-trimester miscarriages, a total of 230 samples were successfully analyzed after the exclusion of 81 specimens based on unsuitable sampling, culture failure, or QF-PCR-proven maternal cell contamination. Chromosome abnormalities were detected in 135 cases (58.7%), with the most common type being single autosomal trisomy (71/135-52.6%), followed by monosomy (monosomy X being the only one detected, 24/135-17.8%), and polyploidy (23/135-17.0%). The subgroup analysis based on maternal age showed a statistically significant higher rate of single trisomy for women aged 35 years or older (40.3%) compared to the young maternal age group (26.1%) (p = 0.029). In conclusion, the combination of conventional karyotyping and QF-PCR can lead to an increased chromosome abnormality detection rate in first-trimester miscarriages. Our study provides reliable information for the genetic counseling of patients with first-trimester miscarriages, and further large-scale studies using different genetic techniques are required.

Investigating the relation between chromosomal polymorphism and recurrent pregnancy loss: A cohort study

Chromosomal polymorphisms (CPM) are minor variation of karyotype, found in &amp;#62;1% of the general population. Heterochromatin, the inactive part of the chromosome, shows frequent polymorphism - increase/decrease in length. Recently, studies show that heterochromatin is not inert, but contains genes essential for spindle attachment, chromosome movement, meiotic pairing, and sister chromatid cohesion. Balanced translocation in parents, reciprocal and robertsonian, can disrupt important genes, and produce gametes with unbalanced gene dosage, causing spontaneous miscarriage. To correlate between chromosomal polymorphisms/ structural alterations and first trimester Recurrent Pregnancy Loss (RPL) primary infertility. : 100 couples with primary infertility or RPLs, were karyotyped by 72-h whole blood culture. Giemsa banding (GTG) was done in all cases. 20 metaphases were analysed according to the ISCN criteria. The total no. of RPLs was noted for each couple with abnormal karyotype. Of the 44 couples with abnormal karyotype, 36 (82%) had chromosomal polymorphism, 7 (16%) showed structural abnormality and 1 (2%) had numerical abnormality. Chromosome 9qh+ was present in the majority (33.33%). Among the D, G chromosomes, chromosome 15ps+/pstk+ were found in 22.22% but average no. of RPL was 2.15, whereas average RPL in Chr.22ps+ (incidence 5.55%.) was 3 (highest). Among male partners, Chr.Yqh+/Yqh- were found in 12 (33.33%) couples. Among the structural abnormalities (16%), balanced translocation accounted for 11.36%, maximum of which were Reciprocal translocations. The frequency of chromosomal abnormalities is higher among couples with RPLs and infertility, compared to the general population. Karyotyping gives important genetic information, thus acting as a good diagnostic tool, and helps to plan ART or perform prenatal testing.

Nickel Increases Chromosomal Abnormalities by Interfering With the Initiation of DNA Repair Pathways

Background: Nickel is a carcinogenic, heavy metal released through industrial activities and via natural resources. It is able to cause DNA damages by reducing the efficiency of DNA repair mechanisms. However, the exact time point at which it is able to interfere with these mechanisms is not yet clearly understood. Methods: To find the most nickel-vulnerable time of repair mechanisms, human dermal fibroblasts (HDF) were treated with three doses of nickel before and after X-irradiation. The induced frequency of chromosomal abnormality was studied using micronucleus assay in binucleated cells. The cytotoxicity of different treatments was established using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results: The results revealed that nickel treatment had a synergistic effect on inducing Micronucleus frequency only when cells were treated 2 hours before X-irradiation. The X-ray treatment of the cells with 5 and 10 mM nickel had a cytotoxic effect mainly when given 6 hours after the irradiation. Conclusion: The results suggest that nickel can interfere with human DNA repair mechanisms only at the start of the process, while having no significant effect on the human DNA repair mechanisms when activated.

Cross-sectional study of chromosomal aberrations and immunologic factors in Iraqi couples with recurrent pregnancy loss.

BackgroundParental chromosomal aberrations are important causes of recurrent pregnancy loss (RPL). Some immunological factors such as antiphospholipid antibodies and interleukin-6 (IL-6) also contribute to this complication. The aim of this study was to determine the frequency of chromosomal abnormalities and to evaluate some of the immunological factors in couples with RPL from different cities in Iraq.MethodsThis study was conducted on 25 couples (50 individuals) who had more than two first trimester abortions in the past and 25 healthy females as controls. Karyotyping was performed on peripheral blood of all participants. Anticardiolipin (IgG and IgM), antiphosopholipid (IgG and IgM), lupus anticoagulant, and IL-6 were assayed. Data were analyzed using appropriate statistical tests.ResultsChromosomal abnormalities were found in 28.0% (n = 7/25) of RPL couples. Of these five (10.0%) were female and two (4.0%) were male. The types of structural abnormalities were as follows: 45, XX, t(21; 21); 45, XX, rob (14, 15); 46, XX, add (21) (p13); 46 XY, add (21)(p13); 46, XX, 21ps+; 46, XY, per inv (9) (p11q12) and 45, XX, t(13q, 13q). No chromosomal abnormalities were found in the control group. Also, no significant differences were found in the immunological parameters of the couples with RPL and the control group.ConclusionIn this study, karyotyping revealed a high number of chromosomal abnormalities associated with the RPL in Iraqi couples. Since identification of genetic causes of miscarriage is important for genetic counseling and educating couples about the risk of future pregnancies, it is recommended that conventional karyotyping be investigated in patients with RPL.

Female Reproductive Ageing and Chromosomal Abnormalities in a Large Series of Women Undergoing IVF

Chromosomal abnormalities are often detected in women with reproductive problems. This study aimed to investigate the presence and type of chromosomal aberrations in peripheral blood of women undergoing in vitro fertilization (IVF) and their possible association with advanced maternal age (AMA). A total of 1,837 women undergoing IVF between 2016 and 2019 were enrolled in the study. Women were further divided in AMA (≥35 years) and younger women (<35 years). Chromosomal abnormalities were detected by peripheral blood karyotyping using standard cytogenetic techniques. Chromosomal abnormalities were detected in 13.5% of the enrolled women; 1.1% had autosomal abnormalities including reciprocal translocations, inversions, Robertsonian translocations, and a supernumerary marker chromosome, while 12.4% had X chromosome abnormalities. The frequency of chromosomal abnormalities was significantly higher in AMA women than in younger ones (17.4% vs. 3.9%, p < 0.05). Women of AMA exhibited X chromosome mosaicism with a frequency of 16.1%, and mosaic karyotypes with 2 and 3 aneuploid cell lines were more frequently detected. X chromosome mosaicism is the most common karyotypic aberration in women undergoing IVF and has 6-fold increased incidence in AMA women compared to younger ones. The present study verifies previous observations that low-level peripheral blood X chromosome mosaicism and the number of aneuploid cell lines observed in women of AMA could be an indication of aneuploidy and poor quality of oocytes contributing to infertility.