Chromosomal Polymorphism Research Articles

Analysis of non-targeted variants by invasive prenatal diagnosis for pregnant women undergoing preimplantation genetic testing

To compare the results of invasive prenatal diagnosis and preimplantation genetic testing (PGT) and explore the underlying mechanism. Clinical data of pregnant women undergoing PGT and invasive prenatal diagnosis at the Sixth Affiliated Hospital of Sun Yat-sen University from January 2019 to December 2022 were collected. The results of PGT and invasive prenatal diagnosis were compared, and the outcomes of pregnancies were followed up. This study has been approved by the Medical Ethics Committee of the Sixth Affiliated Hospital of Sun Yat-sen University (No. 2022ZSLYEC-491). A total of 172 couples were included in this study, and 26 non-targeted variants were discovered upon prenatal diagnosis, including 10 cases (38.5%) by chromosomal karyotyping, 15 (57.7%) by chromosomal microarray analysis (CMA), and 1 (3.8%) by whole exome sequencing. The 10 karyotypic anomalies had included 6 chromosomal polymorphisms, 2 chromosomal mosaicisms, 1 paternally derived translocation, and 1 missed maternal chromosomal inversion. CMA has identified 15 copy number variations (CNVs), which included 11 microdeletions and microduplications, 3 loss of heterozygosity, and 1 low-level mosaicism of paternal uniparental disomy. One CNV was classified as pathogenic, and another one was likely pathogenic, whilst the remaining 13 were classified as variants of uncertain significance. Therefore, 8.7% of CNVs was detected by invasive prenatal diagnosis after PGT. 92.3% (24/26) of the non-targeted variants have been due to technological limitations of next-generation sequencing (NGS). Invasive prenatal diagnosis after PGT can detect non-targeted variants, which may further reduce the incidence of birth defects.

The Value of Parental Karyotyping in Recurrent Pregnancy Loss Lies in Individual Risk Assessments

Background and Objectives: Recurrent pregnancy loss (RPL) is a multifactorial condition, encompassing genetic, anatomical, immunological, endocrine, as well as infectious and environmental factors; however, the etiology remains elusive in a substantial number of cases. Genetic factors linked to RPL include parental karyotype abnormalities (e.g., translocations, inversions, copy number variants), an increase in sperm aneuploidy, fetal microchimerism, severe skewing of X chromosome inactivation, and various gene polymorphisms. Our study aims to explore the value of routine conventional parental karyotyping in couples with RPL. Materials and Methods: A total of 213 couples (426 individuals) with a history of RPL were enrolled in this retrospective study. The peripheral blood samples included in this study were referred to the Human Genomics Laboratory of the University of Medicine and Pharmacy in Craiova, Romania, for conventional cytogenetic analysis between January 2013 and December 2023, by the Outpatient Medical Genetics Clinic of the Emergency Clinical County Hospital of Craiova. Chromosome analysis was performed using standard protocols and karyotypes were reported according to ISCN. Results: Out of 426 patients provided with conventional G-banded chromosome analysis, 410 had a normal karyotype (96.2%) and 16 had chromosome abnormalities (3.8%). The most common chromosomal abnormalities were reciprocal and Robertsonian translocations, with chromosomes 8, 11, 14, and 21 being most frequently involved. A single numerical anomaly was detected (47,XYY). One or multiple chromosomal polymorphisms were identified in 104 subjects (24.4%). In addition, we conducted a stratified analysis of the unselected group and detected chromosome abnormalities in only four cases (0.94%). Conclusions: Our results are consistent with recommendations for paternal karyotyping after an individual risk assessment in instances such as a previous live birth with congenital anomalies and/or the detection of unbalanced chromosomes or a translocation in product of conception or chorionic villi/amniotic fluid samples. In the absence of a positive history, blindly karyotyping couples may prove too expensive and labor intensive, while providing no information on fertility status or live birth rates.

Genetic variation in bovine milk proteins: Implications for functional and nutritional properties

The six major bovine milk proteins are encoded by highly polymorphic chromosomes. Genetic variation has become a topic of interest and controversy in recent years due to supposed adverse health effects, beginning with the A2 variant of β‐casein. The functional implications of genetic variants have been well characterised, specifically heat stability and coagulation (i.e. rennet and acid) properties of milk, which have found that the B variant of β‐casein, κ‐casein and β‐lactoglobulin are the most beneficial. Genetic variants of milk proteins provide considerable potential to create new dairy products to add value to milk.

Trans regulation of an odorant binding protein by a proto-Y chromosome affects male courtship in house fly.

The male-limited inheritance of Y chromosomes favors alleles that increase male fitness, often at the expense of female fitness. Determining the mechanisms underlying these sexually antagonistic effects is challenging because it can require studying Y-linked alleles while they still segregate as polymorphisms. We used a Y chromosome polymorphism in the house fly, Musca domestica, to address this challenge. Two male determining Y chromosomes (YM and IIIM) segregate as stable polymorphisms in natural populations, and they differentially affect multiple traits, including male courtship performance. We identified differentially expressed genes encoding odorant binding proteins (in the Obp56h family) as candidate agents for the courtship differences. Through network analysis and allele-specific expression measurements, we identified multiple genes on the house fly IIIM chromosome that could serve as trans regulators of Obp56h gene expression. One of those genes is homologous to Drosophila melanogaster CG2120, which encodes a transcription factor that binds near Obp56h. Upregulation of CG2120 in D. melanogaster nervous tissues reduces copulation latency, consistent with this transcription factor acting as a negative regulator of Obp56h expression. The transcription factor gene, which we name speed date, demonstrates a molecular mechanism by which a Y-linked gene can evolve male-beneficial effects.

Chromosomal Polymorphism of Malaria Mosquitoes of Karelia and Expansion of Northern Boundaries of Species Areas

Chromosomal variability in peripheral populations of malaria mosquitoes of the genus Anopheles (Diptera, Culicidae) inhabiting the territory of Karelia was studied. The modern northern limits of the ranges of sibling species of malarial mosquitoes An. beklemishevi, An. daciae, An. messeae s. s. and An. maculipennis were established. After 2010, the distribution boundary of malaria mosquitoes shifted northward by 170 km, from the 65th parallel to the Arctic Circle. Inversion heterozygotes XL1, XL2, 2R2, 3R1 and 3R5 were found in peripheral populations of An. beklemishevi. Peripheral populations of An. messeae s. s. were homozygous for inversion of sex chromosome XL1 and differed in the frequencies of autosome inversions from the middle taiga populations. The frequency of heterozygotes for autosomal inversions 2R1, 3R1, and 3L1 increased in populations at the edge of the species area. Chromosomal variability in peripheral populations contributes to the dispersal of malaria mosquitoes in high latitudes under warming climate conditions.

Traces of Paleolithic expansion in the Nivkh gene pool based on data on autosomal SNP and Y chromosome polymorphism.

The Nivkhs are a small ethnic group indigenous of the Russian Far East, living in the Khabarovsk Territory and on Sakhalin Island, descending from the ancient inhabitants of these territories. In the Nivkhs, a specific Sakhalin-Amur anthropological type is prevalent. They are quite isolated, due to long isolation from contacts with other peoples. The gene pool of the Nivkhs and other Far Eastern and Siberian populations was characterized using a genome-wide panel of autosomal single-nucleotide polymorphic markers and Y chromosome haplogroups. Bioinformatic processing of frequencies of autosomal SNPs, Y chromosome haplogroups and YSTR haplotypes showed that the Nivkh gene pool is very different from the other populations'. Analysis of the SNP frequencies using the PCA method divided the Far Eastern populations in full accordance with the territories of their residence into the northern group of the Chukchi and Koryaks and the southern group, including the Nivkhs and Udege. The remoteness of the Nivkhs coincides with their geographic localization, with the Nivkhs and Udege demonstrating the greatest kinship. The Nivkhs have a specific component of their gene pool, which is present with much less frequency in the Udege and Transbaikal Evenks. According to the IBD blocks, the genotypes of the Nivkhs show a very small percentage of coincidence with the Udege, Koryaks, Evenks and Chukchi, the value of which is the lowest compared to the IBD blocks among all other Siberian populations. The Nivkh-specific composition of haplogroups and YSTR haplotypes was shown. In the Nivkhs, the C2a1 haplogroup is divided into three sublines, which have a fairly ancient origin and are associated with the ancestors of modern northern Mongoloids. The Nivkh haplogroup O2a1b1a2a-F238 is found among residents of China and Myanmar. The Q1a1a1-M120 line is represented among the Nivkhs, Koryaks, Evenks and Yukaghirs. Phylogenetic analysis of individual Y chromosomal haplogroups demonstrated the closeness of the Nivkh gene pool with the ancient population of the Amur and Okhotsk regions, the Koryaks, the Tungus peoples and the population of Southeast Asia. The Nivkh gene pool confirms the relative smallness of their ancestral groups without mixing with other populations.

A sex chromosome polymorphism maintains divergent plumage phenotypes between extensively hybridizing yellowhammers (Emberiza citrinella) and pine buntings (E. leucocephalos).

Under allopatric speciation, populations of a species become isolated by a geographic barrier and develop reproductive isolation through genetic differentiation. When populations meet in secondary contact, the strength of evolved reproductive barriers determines the extent of hybridization and whether the populations will continue to diverge or merge together. The yellowhammer (Emberiza citrinella) and pine bunting (E. leucocephalos) are avian sister species that diverged in allopatry on either side of Eurasia during the Pleistocene glaciations. Though they differ greatly in plumage and form distinct genetic clusters in allopatry, these taxa show negligible mitochondrial DNA differentiation and hybridize extensively where they overlap in central Siberia, lending uncertainty to the state of reproductive isolation in the system. To assess the strength of reproductive barriers between taxa, we examined genomic differentiation across the system. We found that extensive admixture has occurred in sympatry, indicating that reproductive barriers between taxa are weak. We also identified a putative Z chromosome inversion region that underlies plumage variation in the system, with the 'pine bunting' haplotype showing dominance over the 'yellowhammer' haplotype. Our results suggest that yellowhammers and pine buntings are currently at a crossroads and that evolutionary forces may push this system towards either continued differentiation or population merging. However, even if these taxa merge, recombination suppression between putative chromosome Z inversion haplotypes may maintain divergent plumage phenotypes within the system. In this way, our findings highlight the important role hybridization plays in increasing the genetic and phenotypic variation as well as the evolvability of a system.

Exploring Chromosomal Polymorphism and Evolutionary Implications in Rineloricaria lanceolata (Günther, 1868) (Siluriformes: Loricariidae): Insights from Meiotic Behavior and Phylogenetic Analysis.

Chromosomal polymorphism is a significant aspect of population genetics, influencing the adaptation and evolution of species. In Rineloricaria lanceolata, a Neotropical fish species, chromosomal polymorphism has been observed, yet the underlying mechanisms and evolutionary implications remain poorly understood. This article aims to investigate the chromosomal polymorphism in Rineloricaria lanceolata, focusing on elucidating the meiotic behavior of karyotypic variants and tracing the phylogenetic origins of this polymorphism within the genus. By employing molecular markers and cytogenetic techniques, we aim to uncover the mechanisms driving chromosomal rearrangements and their potential role in speciation and adaptation. Understanding the genetic basis of chromosomal polymorphism in R. lanceolata not only contributes to our knowledge of species evolution but also holds implications for the conservation of genetic diversity within this vulnerable group of Neotropical fishes.

Exploring the link between chromosomal polymorphisms and reproductive abnormalities

ObjectiveThis work aimed to investigate the potential correlation between chromosomal polymorphisms and various reproductive abnormalities.MethodsWe examined 21,916 patients affected by infertility who sought care at the Department of Reproductive Medicine, Affiliated Hospital of Shandong Second Medical University between January 2018 and December 2022. A total of 2227 individuals identified as chromosomal polymorphism carriers constituted the polymorphism group, and 2245 individuals with normal chromosome karyotypes were randomly selected to form a control group. Clinical manifestations, histories of spontaneous miscarriage, abnormal reproductive developments, fetal abnormalities, and male sperm quality anomalies were statistically compared between these two groups.ResultsOf the 21,916 patients analyzed, 2227 displayed chromosomal polymorphism, representing a 10.16% detection rate. Amongst the male patients, 1622 out of 10,827 exhibited polymorphisms (14.98%), whereas 605 out of 11,089 females showed polymorphisms (5.46%). Female carriers in the polymorphism group, showed statistically significant increased rates of spontaneous abortion (29.75% vs. 18.54%), fetal anomalies (1.32% vs. 0.81%), and uterine abnormalities compared with the control group (1.32% vs. 0.81%). Male carriers in the polymorphism group had higher rates of spontaneous abortion in partners (22.87% vs. 10.37%), fetal anomalies (1.97% vs. 0.25%), compromised sperm quality (41.74% vs. 7.18%), testicular underdevelopment (2.28% vs. 0.92%), and hypogonadotropic hypogonadism (0.62% vs. 0.37%) compared with the control group.ConclusionChromosomal polymorphisms may have a certain negative effect on reproductive irregularities, including spontaneous abortions, fetal anomalies, and reduced sperm quality in males. Their clinical effects deserve further investigation.

A chromosome-level genome assembly of Drosophila madeirensis, a fruit fly species endemic to the island of Madeira.

Drosophila subobscura is distributed across Europe, the Near East, and the Americas, while its sister species, Drosophila madeirensis, is endemic to the island of Madeira in the Atlantic Ocean. D. subobscura is known for its strict light-dependence in mating and its unique courtship displays, including nuptial gift-giving. D. subobscura has also attracted the interest of researchers because of its abundant variations in chromosomal polymorphisms correlated to the latitude and season, which have been used as a tool to track global climate warming. Although D. madeirensis can be an important resource for understanding the evolutionary underpinning of these genetic characteristics of D. subobscura, little work has been done on the biology of this species. Here, we used a HiFi long-read sequencing data set to produce a de novo genome assembly for D. madeirensis. This assembly comprises a total of 111 contigs spanning 135.5 Mb and has an N50 of 24.2 Mb and a BUSCO completeness score of 98.6%. Each of the 6 chromosomes of D. madeirensis consisted of a single contig except for some centromeric regions. Breakpoints of the chromosomal inversions between D. subobscura and D. madeirensis were characterized using this genome assembly, updating some of the previously identified locations.

New insights on the chromosomal inversion thermal adaptation in insects: American populations of Drosophila subobscura

AbstractDrosophila subobscura is an excellent model species for testing genetic variation in thermal adaptation due to its rich inversion chromosomal polymorphism. In Palearctic populations, the inversions of this species can be classified as “cold”, “warm” or “nonthermal” adapted. Based on this classification the Chromosomal Thermal Index (CTI) was developed, which allows measuring the thermal adaptation of populations and monitoring changes over time. Here, we aim to use this index in American colonizing populations of D. subobscura for the first time to obtain new information on the species thermal adaptation. Thus, thermal adapted inversions (“cold” and “warm”) were defined for the American continent and CTI was computed in South American (1981 and 1999 samples) and North American (1985 and 2004 samples) populations of D. subobscura. In general, both American populations showed an inverse relationship between CTI values and latitude, with CTI values decreasing when latitude increases. When comparing populations sampled in different years, an increase in CTI values was detected in four out of six temporal comparisons (only one was significant) of South America (1981 and 1999) and in six out of seven populations of North America (1985 and 2004). A global analysis using a one‐way repeated measures anova of CTI values in both American hemispheres showed a trend of increase for “warm” adapted inversions in Chile and North America, but this increase was only significant for the latter. Overall, these results are in agreement with global warming expectations, although natural selection acted differently in the colonized hemispheres.

Intraspecific diploidization of a halophyte root fungus drives heterosis

How organisms respond to environmental stress is a key topic in evolutionary biology. This study focused on the genomic evolution of Laburnicola rhizohalophila, a dark-septate endophytic fungus from roots of a halophyte. Chromosome-level assemblies were generated from five representative isolates from structured subpopulations. The data revealed significant genomic plasticity resulting from chromosomal polymorphisms created by fusion and fission events, known as dysploidy. Analyses of genomic features, phylogenomics, and macrosynteny have provided clear evidence for the origin of intraspecific diploid-like hybrids. Notably, one diploid phenotype stood out as an outlier and exhibited a conditional fitness advantage when exposed to a range of abiotic stresses compared with its parents. By comparing the gene expression patterns in each hybrid parent triad under the four growth conditions, the mechanisms underlying growth vigor were corroborated through an analysis of transgressively upregulated genes enriched in membrane glycerolipid biosynthesis and transmembrane transporter activity. In vitro assays suggested increased membrane integrity and lipid accumulation, as well as decreased malondialdehyde production under optimal salt conditions (0.3 M NaCl) in the hybrid. These attributes have been implicated in salinity tolerance. This study supports the notion that hybridization-induced genome doubling leads to the emergence of phenotypic innovations in an extremophilic endophyte.

Clinical Analysis of Y Chromosome Microdeletions and Chromosomal Aberrations in 1596 Male Infertility Patients of the Zhuang Ethnic Group in Guangxi.

The long arm of the Y chromosome (Yq) contains many amplified and palindromic sequences that are prone to self-reorganization during spermatogenesis, and tiny submicroscopic segmental deletions in the proximal Yq are called Y chromosome microdeletions (YCM). A retrospective study was conducted on male infertility patients of Zhuang ethnicity who presented at Reproductive Medical Center of Nanningbetween January 2015 and May 2023. Seminal fluid was collected for standard examination. YCM were detected by using a combination of multiplex PCR and agarose gel electrophoresis. Preparation of peripheral blood chromosomes and karyotyping of chromosomes was performed. 147 cases (9.22%) of YCM were detected in 1596 maleinfertility patients of Zhuang ethnicity. Significant difference was found in the detection rate of YCM between the azoospermia group and the oligospermia group (P < 0.001). Of all types of YCM, the highest detection rate was AZFc (n = 83), followed by AZFb + c (n = 28). 264 cases (16.54%) of sex chromosomal aberrations were detected. The most prevalent karyotype was 47, XXY (n = 202). The detection rate of sex chromosomal aberrations in azoospermia group was higher than that in severe oligospermia group and oligospermia group, and the differences were significant (P < 0.001). 28 cases (1.57%) of autosomal aberrations and 105 cases (6.58%) of chromosomal polymorphism were identified. The current research has some limitations due to the lack of normal men as the control group but suggests that YCM and chromosomal aberrations represent key genetic factors influencing spermatogenesis in infertile males of Zhuang ethnicity in Guangxi.

Inversions Can Accumulate Balanced Sexual Antagonism: Evidence from Simulations and Drosophila Experiments.

Chromosomal inversion polymorphisms can be common, but the causes of their persistence are often unclear. We propose a model for the maintenance of inversion polymorphism, which requires that some variants contribute antagonistically to two phenotypes, one of which has negative frequency-dependent fitness. These conditions yield a form of frequency-dependent disruptive selection, favoring two predominant haplotypes segregating alleles that favor opposing antagonistic phenotypes. An inversion associated with one haplotype can reduce the fitness load incurred by generating recombinant offspring, reinforcing its linkage to the haplotype and enabling both haplotypes to accumulate more antagonistic variants than expected otherwise. We develop and apply a forward simulator to examine these dynamics under a tradeoff between survival and male display. These simulations indeed generate inversion-associated haplotypes with opposing sex-specific fitness effects. Antagonism strengthens with time, and can ultimately yield karyotypes at surprisingly predictable frequencies, with striking genotype frequency differences between sexes and between developmental stages. To test whether this model may contribute to well-studied yet enigmatic inversion polymorphisms in Drosophila melanogaster, we track inversion frequencies in laboratory crosses to test whether they influence male reproductive success or survival. We find that two of the four tested inversions show significant evidence for the tradeoff examined, with In(3R)K favoring survival and In(3L)Ok favoring male reproduction. In line with the apparent sex-specific fitness effects implied for both of those inversions, In(3L)Ok was also found to be less costly to the viability and/or longevity of males than females, whereas In(3R)K was more beneficial to female survival. Based on this work, we expect that balancing selection on antagonistically pleiotropic traits may provide a significant and underappreciated contribution to the maintenance of natural inversion polymorphism.

Robertsonian Translocation between Human Chromosomes 21 and 22, Inherited across Three Generations, without Any Phenotypic Effect

Chromosomal translocations can result in phenotypic effects of varying severity, depending on the position of the breakpoints and the rearrangement of genes within the interphase nucleus of the translocated chromosome regions. Balanced translocations are often asymptomatic phenotypically and are typically detected due to a decrease in fertility resulting from issues during meiosis. Robertsonian translocations are among the most common chromosomal abnormalities, often asymptomatic, and can persist in the population as a normal polymorphism. We serendipitously discovered a Robertsonian translocation between chromosome 21 and chromosome 22, which is inherited across three generations without any phenotypic effect, notably only in females. In situ hybridization with alpha-satellite DNAs revealed the presence of both centromeric sequences in the translocated chromosome. The reciprocal translocation resulted in a partial deletion of the short arm of both chromosomes 21, and 22, with the ribosomal RNA genes remaining present in the middle part of the new metacentric chromosome. The rearrangement did not cause alterations to the long arm. The spread of an asymptomatic heterozygous chromosomal polymorphism in a population can lead to mating between heterozygous individuals, potentially resulting in offspring with a homozygous chromosomal configuration for the anomaly they carry. This new karyotype may not produce phenotypic effects in the individual who presents it. The frequency of karyotypes with chromosomal rearrangements in asymptomatic heterozygous form in human populations is likely underestimated, and molecular karyotype by array Comparative Genomic Hybridization (array-CGH) analysis does not allow for the identification of this type of chromosomal anomaly, making classical cytogenetic analysis the preferred method for obtaining clear results on a karyotype carrying a balanced rearrangement.

Chromosomal Polymorphism of Malaria Mosquitoes of Karelia and Expansion of Northern Boundaries of Species Ranges

Chromosomal Polymorphism of Malaria Mosquitoes of Karelia and Expansion of Northern Boundaries of Species Ranges

Diverse impacts of female chromosomal polymorphisms on assisted reproduction outcomes: a retrospective cohort study

BackgroundThe effects of female chromosomal polymorphisms (FCPs) on various aspects of reproductive health have been investigated, yet the findings are frequently inconsistent. This study aims to clarify the role of FCPs on the outcomes of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI).MethodsThis retrospective cohort study comprised 951 couples with FCPs and 10,788 couples with normal karyotypes who underwent IVF/ICSI treatment at Peking University Third Hospital between 2015 and 2021. The exposure was FCPs. The embryological outcomes and clinical outcomes were compared.ResultsThe FCPs, as a whole, compromised the oocyte maturation rate (76.0% vs. 78.8%, P = 0.008), while they did not adversely affect other IVF/ICSI outcomes. Further detailed analyses showed that every type of FCPs contributed to the lower oocyte maturation rate, particularly the rare FCPs (69.0% vs. 78.8%, P = 0.008). The female qh + was associated with a higher normal fertilization rate (63.0% vs. 59.2%, adjusted P = 0.022), a higher clinical pregnancy rate (37.0% vs. 30.7%, adjusted P = 0.048), and a higher live birth rate (27.0% vs.19.0%, adjusted P = 0.003) in couples undergoing IVF. Conversely, in couples undergoing ICSI, female qh + was found to be related to a lower normal fertilization rate (58.8% vs. 63.8%, P = 0.032), a comparable clinical pregnancy rate (25.7% vs. 30.9%, P = 0.289), and a comparable live birth rate (19.8% vs. 19.2%, P = 0.880) compared to the control group. Additionally, an increased risk of preterm birth was observed in women undergoing IVF with multiple polymorphisms (62.5% vs. 16.9%, adjusted P < 0.001) and in women undergoing ICSI with pstk+ (36.4% vs. 15.4%, P = 0.036).ConclusionsOur research unravels the diverse impacts of various FCPs on IVF/ICSI outcomes, highlighting the detrimental effects of FCPs on oocyte maturation and the risk of preterm birth.

The Relationship Between Chromosomal Polymorphism and Male Reproductive Abnormalities.

This study aims to investigate the association between chromosomal polymorphisms and abnormalities in male reproductive health. Within the period from January 2018 to December 2022, a cohort of 10,827 males seeking fertility services at our reproductive center was selected for inclusion in this study. Peripheral blood chromosomal karyotype analysis was conducted for each participant to identify carriers of chromosomal polymorphisms, who were subsequently categorized into a polymorphism group. Additionally, a control group was constituted by randomly selecting 1,630 patients exhibiting normal chromosomal karyotypes. The study conducted statistical analyses to compare clinical outcomes between the two groups, focusing on infertility, history of spontaneous miscarriage in partners, anomalies in reproductive development, fetal abnormalities, and sperm quality metrics. (1) Among the cohort of 10,827 males, chromosomal polymorphisms were identified in 1,622 participants, yielding a detection rate of 14.98%. This rate is significantly elevated in comparison to the baseline prevalence of 1.77% observed in the general population. (2) The predominant variant among these polymorphisms was related to the Y chromosome, accounting for 1,082 cases (66.71% of the polymorphic findings), corresponding to a detection rate of 9.99%. This is markedly higher than the approximate 0.09% prevalence noted within a normative demographic. (3) Statistical analysis revealed significant disparities between the chromosomal polymorphism group and the control group in several clinical outcomes. Notably, the rates of spontaneous abortion (18.06% vs. 1.35%), fetal anomalies (1.97% vs. 0.25%), and poor sperm quality (41.74% vs. 7.18%) were markedly higher in the polymorphism group. Additionally, incidences of testicular dysgenesis (2.28% vs. 0.92%) and hypogonadism in partners (0.62% vs. 0.37%) also demonstrated significant differences, underscoring the potential reproductive implications of chromosomal polymorphisms. The study establishes a significant link between chromosomal polymorphisms and critical reproductive outcomes, including male infertility, spontaneous miscarriages in partners, fetal anomalies, and reduced sperm quality. These findings highlight the clinical relevance of chromosomal polymorphisms in reproductive health assessments and suggest the necessity for their consideration in the diagnostic and therapeutic strategies for male reproductive disorders.

Chromosomal Damage, Chromosome Instability, and Polymorphisms in GSTP1 and XRCC1 as Biomarkers of Effect and Susceptibility in Farmers Exposed to Pesticides.

In the department of Boyacá, Colombia, agriculture stands as one of the primary economic activities. However, the escalating utilization of pesticides within this sector has sparked concern regarding its potential correlation with elevated risks of genotoxicity, chromosomal alterations, and carcinogenesis. Furthermore, pesticides have been associated with a broad spectrum of genetic polymorphisms that impact pivotal genes involved in pesticide metabolism and DNA repair, among other processes. Nonetheless, our understanding of the genotoxic effects of pesticides on the chromosomes (as biomarkers of effect) in exposed farmers and the impact of genetic polymorphisms (as susceptibility biomarkers) on the increased risk of chromosomal damage is still limited. The aim of our study was to evaluate chromosomal alterations, chromosomal instability, and clonal heterogeneity, as well as the presence of polymorphic variants in the GSTP1 and XRCC1 genes, in peripheral blood samples of farmers occupationally exposed to pesticides in Aquitania, Colombia, and in an unexposed control group. Our results showed statistically significant differences in the frequency of numerical chromosomal alterations, chromosomal instability, and clonal heterogeneity levels between the exposed and unexposed groups. In addition, we also found a higher frequency of chromosomal instability and clonal heterogeneity in exposed individuals carrying the heterozygous GSTP1 AG and XRCC1 (exon 10) GA genotypes. The evaluation of chromosomal alterations and chromosomal instability resulting from pesticide exposure, combined with the identification of polymorphic variants in the GSTP1 and XRCC1 genes, and further research involving a larger group of individuals exposed to pesticides could enable the identification of effect and susceptibility biomarkers. Such markers could prove valuable for monitoring individuals occupationally exposed to pesticides.

Impacts of male chromosomal polymorphisms on semen quality and IVF/ICSI outcomes: A retrospective cohort study.

The study aims to elucidate the impacts of different types of male chromosomal polymorphisms (MCPs) on various outcomes of invitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) treatment. This retrospective cohort study included 1442 couples with normal karyotypes, 1442 couples with MCPs, 42 couples with male chromosomal rearrangements (MCRs), and 42 couples with MCRs combined with MCPs who underwent IVF/ICSI treatment at Peking University Third Hospital from 2015 to 2021. The semen quality, embryological outcomes, and clinical outcomes of different groups stratified by karyotypes were compared. For couples undergoing IVF, male inv(9) was associated with a significantly lower sperm viability rate (29.41% vs 34.49%, P = 0.030), a lower progressive motility rate (25.13% vs 30.50%, P = 0.013), and a lower normal fertilization rate (52.41% vs 59.84%, P = 0.014). Male 9qh + was related to a lower sperm viability rate (27.56% vs 34.49%, P = 0.028). No MCPs were observed to compromise clinical outcomes in couples undergoing IVF. For couples undergoing ICSI, no MCPs exhibited an association with poorer semen quality and embryological outcomes. However, Yqh + and DGpstk+ were found to be significantly correlated with an increased likelihood of preterm birth (23.3% vs 9.2%, P = 0.003; 20.0% vs 9.2%, P = 0.041, respectively). In couples with MCRs, the presence of MCPs significantly reduced the sperm viability rate (19.99% vs 30.97%, P = 0.017) and progressive motility rate (8.07% vs 27.85%, P = 0.018). Our study provides detailed evidence for the impacts of various MCPs on IVF/ICSI outcomes, reveals the complexity and heterogeneity of these impacts, and highlights the adverse effects of male inv(9).