Heterochromatin variants in human karyotypes: a possible association with reproductive failure

Challenges in classifying human chromosomal heteromorphisms using banding cytogenetics: From controversial guidelines to the need for a universal scoring system

Chromosomal heteromorphisms (CHs) are morphological variations predominantly found in constitutive heterochromatic regions of the genome, primarily composed of tandemly repetitive sequences of satellite DNA. Although not completely devoid of genes, these regions are typically not transcribed into proteins and lack obvious phenotypic impact. Nonetheless, their clinical importance is increasingly under scrutiny, with several studies aiming to assess their influence on human diseases and susceptibilities, especially as they are seemingly part of the long noncoding RNAs in certain tissues. This article summarizes the classification methods of human heterochromatic CHs documented in the literature over the last two decades. Multiple scoring systems have been identified, and previous approaches for CH assessment and reporting in genetic diagnosis have shown inconsistencies. Owing to the current heterogeneity in the classification of CHs, data analysis may be biased, impacting the quality of clinical reports and human genetic research. This review highlights the need for a universal scoring system, which is essential for scientific reproducibility and the accurate identification and clinical evaluation of human CHs.

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

OBJECTIVE

The study aims to elucidate the impacts of different types of male chromosomal polymorphisms (MCPs) on various outcomes of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) treatment.

METHODS

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.

RESULTS

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).

CONCLUSION

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).

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

BACKGROUND

The 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).

METHODS

This 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.

RESULTS

The 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).

CONCLUSIONS

Our 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.

Chromosomal polymorphisms in assisted reproduction: a systematic review and meta-analysis

This systematic review and meta-analysis investigated the effects of chromosomal polymorphisms in reproductive outcomes following IVF or ICSI. Literature in CENTRAL, CINAHL, EMBASE and MEDLINE were searched from 1974 to March 2020 with no language restrictions. Ten published cohort studies were chosen for analysis. Studies included females, males and couples undergoing assisted reproductive treatments with the presence or absence of chromosomal polymorphisms. Reproductive outcomes were reported and their quality assessed using the Newcastle-Ottawa Quality Assessment Scale. Meta-analysis of five cohort studies (9,659 participants) indicated that female carriers with chromosomal polymorphisms had a higher miscarriage rate compared to non-carriers (risk ratio (RR) 1.54 (95% CI 1.19-1.98), whereas no significant association was found for males (RR 0.96, 95% CI 0.64-1.43) and couples (RR 1.93, 95% CI 0.32-11.83) indicating that this effect appeared to be gender-dependent. There was no association between chromosomal polymorphisms and a higher rate of biochemical, clinical, ongoing pregnancy, and preterm and live birth.

Polymorphic Rearrangements of Human Chromosome 9 and Male Infertility: New Evidence and Impact on Spermatogenesis

Chromosomal polymorphisms are structural variations in chromosomes that define the genomic variance of a species. These alterations are recurrent in the general population, and some of them appear to be more recurrent in the infertile population. Human chromosome 9 is highly heteromorphic, and how its rearrangement affects male fertility remains to be fully investigated. In this study, we aimed to investigate the association between the polymorphic rearrangements of chromosome 9 and male infertility via an Italian cohort of male infertile patients. Cytogenetic analysis was carried out, along with Y microdeletion screening, semen analysis, fluorescence in situ hybridization, and TUNEL assays using spermatic cells. Chromosome 9 rearrangements were observed in six patients: three of them showed a pericentric inversion, while the others showed a polymorphic heterochromatin variant 9qh. Of these, four patients exhibited oligozoospermia associated with teratozoospermia, along with a percentage of aneuploidy in the sperm of above 9%, in particular, an increase in XY disomy. Additionally, high values for sperm DNA fragmentation (≥30%) were observed in two patients. None of them had microdeletions to the AZF loci on chromosome Y. Our results suggest that polymorphic rearrangements of chromosome 9 might be associated with abnormalities in sperm quality due to incorrect spermatogenesis regulation.

Prevalence of Chromosomal Abnormalities in Iranian Patients with Infertility

BACKGROUND

The numerical and structural abnormalities of chromosomes are the most common cause of infertility. Here, we evaluated the prevalence and types of chromosomal abnormalities in Iranian infertile patients.

METHODS

We enrolled 1750 couples of reproductive age with infertility, who referred to infertility clinics in Tehran during 2014- 2019, in order to perform chromosomal analysis. Peripheral blood samples were obtained from all couples and chromosomal abnormalities were evaluated by G-banded metaphase karyotyping. In some cases, the detected abnormalities were confirmed using fluorescence in-situ hybridization (FISH).

RESULTS

We detected various chromosomal abnormalities in 114/3500 (3.257%) patients with infertility. The prevalence of chromosomal abnormalities was 44/114 (38.596%) among infertile females and 70/114 (61.403%) among infertile males. Structural chromosomal abnormalities were found in 27/1750 infertile females and 35/1750 infertile males. Numerical chromosomal abnormalities were found in 17/1750 of females and 35/1750 of males. The 45, XY, rob (13;14) (p10q10) translocation and Klinefelter syndrome (47, XXY) were the most common structural and numerical chromosomal abnormalities in the Iranian infertile patients, respectively.

CONCLUSION

In general, we found a high prevalence of chromosomal abnormalities in Iranian patients with reproductive problems. Our study highlights the importance of cytogenetic studies in infertile patients before starting infertility treatments approaches.

A comprehensive analysis of chromosomal polymorphic variants on reproductive outcomes after intracytoplasmic sperm injection treatment

Recent studies suggest that chromosomal polymorphic variations are associated with infertility. A systematic review of chromosomal polymorphisms in assisted reproduction found an association with higher rates of miscarriage. Aim of this study is to analyse the influence of specific types or number of chromosomal polymorphic variations on reproductive outcomes of couples undergoing ICSI treatment. We analysed data from 929 fresh and frozen embryo transfer cycles of 692 women who underwent karyotyping analysis using Giemsa-Trypsin-Leishman (GTL) banding prior to the ICSI procedure at the Fertility Centre of Lanka Hospitals Corporation Plc, Sri Lanka, from January 2016 to December 2018. The outcomes of interest were the pregnancy, miscarriage and live birth rate per cycle. There was no evidence of a difference in the reproductive outcomes between carriers or non-carriers of any type or number of chromosomal polymorphic variation. Our data, in contrast to previous studies, does not support a deleterious effect for the type or number of chromosomal polymorphic variations on reproductive outcomes. However, additional prospective, adequately powered studies, conducted in multiethnic populations, are required to further investigate whether the detection of chromosomal polymorphic variants prior to assisted conception may in fact be a futile diagnostic tool.

The Progress of Research on Genetic Factors of Recurrent Pregnancy Loss

Recurrent pregnancy loss (RPL) is both mental and physical health problem affecting about 1-5% of women of childbearing age. The etiology of RPL is complex, involving chromosomal abnormalities, autoimmune diseases, metabolic disorders, and endometrial dysfunction. The causes of abortion are still unknown in more than 50% of these cases. With the development of science and technology, an increasing number of scholars focus on this field and find that genetic factors may play an essential role in unexplained RPL, such as embolism-related genes, immune factor-related genes, and chromosomal numeric, and structural variation. This review summarizes the genetic factors associated with RPL, including genetic mutations and genetic polymorphisms, chromosomal variants, and chromosomal polymorphisms. Many related genetic factors have been found to be demographically and geographically relevant, some of which can be used for risk prediction or screening for the etiology of RPL. However, it is difficult to predict and prevent RPL due to uncertain pathogenesis and highly variable clinical presentation. Therefore, the genetic factors of RPL still need plentiful research to obtain a more accurate understanding of its pathogenesis and to provide more detection means for the screening and prevention of RPL.

Cytogenetic Investigation of Infertile Patients in Hungary: A 10-Year Retrospective Study

Chromosome abnormalities play a crucial role in reproductive failure. The presence of numerical or structural aberrations may induce recurrent pregnancy loss or primary infertility. The main purpose of our study was to determine the types and frequency of chromosomal aberrations in infertile patients and to compare the frequency of structural aberrations to a control group. Karyotyping was performed in 1489 men and 780 women diagnosed with reproductive failure between 2010 and 2020. The control group included 869 male and 1160 female patients having cytogenetic evaluations for reasons other than infertility. Sex chromosomal aberrations were detected in 33/1489 (2.22%) infertile men and 3/780 (0.38%) infertile women. Structural abnormalities (e.g., translocation, inversion) were observed in 89/1489 (5.98%) infertile men and 58/780 (7.44%) infertile women. The control population showed structural chromosomal abnormalities in 27/869 (3.11%) men and 39/1160 (3.36%) women. There were significant differences in the prevalence of single-cell translocations between infertile individuals (males: 3.5%; females: 3.46%) and control patients (males: 0.46%; females: 0.7%). In summary, this is the first report of cytogenetic alterations in infertile patients in Hungary. The types of chromosomal abnormalities were comparable to previously published data. The prevalence of less-studied single-cell translocations was significantly higher in infertile patients than in the control population, supporting an earlier suggestion that these aberrations may be causally related to infertility.

A Korean Child with Schaaf-Yang Syndrome Presented with Hearing Impairment: A Case Report

Schaaf-Yang syndrome (SYS) is a rare genomic imprinting disorder caused by truncating mutations in the paternally derived MAGE family member L2 (<i>MAGEL2</i>) allele. It is also responsible for Prader-Willi syndrome, characterized by neonatal hypotonia, developmental delay, intellectual disability, respiratory distress in early infancy, and arthrogryposis. More than 250 individuals with approximately 57 different molecular variants have been reported since 2013, but the phenotype-genotype association in SYS is not yet fully understood. Here, we describe the case of a Korean patient diagnosed with SYS harboring a mutation in the paternal allele of <i>MAGEL2</i>: c.2895G>A, resulting in a protein change of p.Trp965*. The patient’s phenotype included respiratory distress, arthrogryposis, hypotonia, and feeding difficulty in the early neonatal period. Mild renal dysfunction and hearing impairment were observed during infancy.

Chromosomal polymorphisms in assisted reproduction: an analysis of 942 cycles

The use of intracytoplasmic sperm injection (ICSI) has recently increased worldwide. The live birth rate per ICSI cycle is low, and over half of infertile couples remain childless. Chromosomal polymorphisms are up to five times more common in couples with infertility compared to the general population. We aimed to investigate the association between chromosomal polymorphisms and reproductive outcomes in couples undergoing ICSI treatment. We analysed 942 ICSI fresh and frozen embryo transfer cycles in 697 women who underwent karyotyping analysis using Giemsa-Trypsin-Leishman banding prior to assisted conception at the Fertility Centre of Lanka Hospitals, Sri Lanka, between 2016 and 2018. The primary outcomes were pregnancy, miscarriage, and live birth rates. We compared outcomes according to the presence or absence of chromosomal polymorphism in females, males and couples. There were 294 pregnancies (31.2%) recorded in the study; 130 suffered a miscarriage (13.8%), 13 were ectopic pregnancies (1.3%) and 151 resulted in a live birth (16.0%). The evidence from univariable and multivariable analyses (adjusted for age, BMI, ovarian reserve and treatment type) did not confidently identify a difference in pregnancy, miscarriage or live birth rates between couples with no chromosomal polymorphisms compared to couples where the female, male or both partners were carriers of a chromosomal polymorphism. Further, we did not identify a clear association between the presence of chromosomal polymorphisms and reproductive outcomes compared to participants without chromosomal polymorphisms. Wide CIs precluded the identification of clinically meaningful associations.

The complete sequence of a human genome

Since its initial release in 2000, the human reference genome has covered only the euchromatic fraction of the genome, leaving important heterochromatic regions unfinished. Addressing the remaining 8% of the genome, the Telomere-to-Telomere (T2T) Consortium presents a complete 3.055 billion-base pair sequence of a human genome, T2T-CHM13, that includes gapless assemblies for all chromosomes except Y, corrects errors in the prior references, and introduces nearly 200 million base pairs of sequence containing 1956 gene predictions, 99 of which are predicted to be protein coding. The completed regions include all centromeric satellite arrays, recent segmental duplications, and the short arms of all five acrocentric chromosomes, unlocking these complex regions of the genome to variational and functional studies.

Analysis of Aneuploidy Rate and Pregnancy Outcomes in Unexplained Recurrent Pregnancy Loss Couples With Chromosome Polymorphism After PGT-A

Purpose

The study aims to investigate whether chromosomal polymorphism affects embryo development and pregnancy outcomes of unexplained recurrent pregnancy loss (uRPL) couples undergoing PGT-A.

Methods

A total of 585 couples with uRPL history who performed PGT-A were included in the retrospective study from January 2016 to December 2020. We included 415 couples with normal karyotype and 170 couples with chromosomal polymorphism. Furthermore, the polymorphism group was divided into two subgroups: 113 couples in the male group and 57 couples in the female group. The embryo development and pregnancy outcomes were analyzed in different groups.

Results

The blastocyst rate and aneuploidy rate are statistically different in the normal group, male polymorphism group, and female polymorphism group. Compared with normal and female groups, the male group has a lower blastocyst rate, which is statistically different (48.3 vs. 53.9%, p = 0.003; 48.3 vs. 54.1%, p = 0.043). Moreover, the aneuploidy rate of the male polymorphism group is significantly higher than female carriers (29.5 vs. 18.6%, p = 0.003). However, there were no statistically significant differences in clinical pregnancy rate, early miscarriage rate, and live birth rate after PGT-A (p &gt; 0.05).

Conclusion

Male with chromosome polymorphism (CPM) have a lower blastocyst rate and a higher aneuploidy rate than female carriers in uRPL couples undergoing PGT-A. However, when a euploid blastocyst was first transferred, no difference in pregnancy outcomes was found between the male and female polymorphism carriers. It indicated that CPM may have an adverse effect on the embryos of male carriers with uRPL history, and the occurrence of uRPL may be decreased in male polymorphism carriers after PGT-A.

Congenital aphallia associated with congenital urethrorectal fistula: A rare case report

RATIONALE

Aphallia is an extremely rare congenital malformation of unknown cause, with few reports in the literature. It is usually associated with other urogenital and gastrointestinal anomalies and is believed to be a result of either the absence of a genital tubercle or chromosome polymorphism. Herein, we describe an extremely rare case of congenital aphallia with congenital urethrorectal fistula and describe our treatment for this patient.

PATIENT CONCERNS

An 8-year-old boy was brought to our hospital by his parents because of congenital absence of the penis. The child was male per karyotype and had excess heterochromatin on chromosome 9 (46 XY with 9 qh+). No urethral orifice was identified, and urine passed rectally since birth; thus, urinary tract outlet obstruction led to urine reflux from the anus to the epididymis for a long time. The boy had to be placed on prophylactic antibiotics because he developed urinary tract infection and epididymitis almost every day.

DIAGNOSIS

Congenital aphallia (46 XY normal male karyotype) associated with congenital urethroretal fistula.

INTERVENTIONS

We performed urethral exteriorization via perineal urethroplasty and urethrorectal fistula repair. The parents approved for phallic reconstruction when the boy reached puberty.

OUTCOME

A new external urethral orifice was created on the lower scrotum. The urinary reflux was corrected, and the epididymitis symptoms disappeared. The urethral fistula was then closed. At 8 months follow up, the patient was no longer on antibiotics and had no symptoms of urinary tract infection or epididymitis.

CONCLUSIONS

Compatible treatment should be adopted to address urinary tract drainage and infection. Management requires a stepwise approach to address needs as they arise. Neophalloplasty should be performed by an experienced team in early adolescence.

Characterization of Chromosomal Instability in Glioblastoma

Glioblastoma multiforme (GBM) is a malignant tumor of the central nervous system (CNS). The poor prognosis of GBM due to resistance to therapy has been associated with high chromosomal instability (CIN). Replication stress is a major cause of CIN that manifests as chromosome rearrangements, fragility, and breaks, including those cytologically expressed within specific chromosome regions named common fragile sites (CFSs). In this work, we characterized the expression of human CFSs in the glioblastoma U-251 MG cell line upon treatment with the inhibitor of DNA polymerase alpha aphidicolin (APH). We observed 52 gaps/breaks located within previously characterized CFSs. We found 17 to be CFSs in GBM cells upon treatment with APH, showing a frequency equal to at least 1% of the total gaps/breaks. We report that two CFSs localized to regions FRA2E (2p13/p12) and FRA2F (2q22) were only found in U-251 MG cells, but not lymphocytes or fibroblasts, after APH treatment. Notably, these glioblastoma-specific CFSs had a relatively high expression compared to the other CFSs with breakage frequency between ∼7 and 9%. Presence of long genes, incomplete replication, and delayed DNA synthesis during mitosis (MiDAS) after APH treatment suggest that an impaired replication process may contribute to this loci-specific fragility in U-251 MG cells. Altogether, our work offers a characterization of common fragile site expression in glioblastoma U-251 MG cells that may be further exploited for cytogenetic and clinical studies to advance our understanding of this incurable cancer.

Acrocentric Chromosome Polymorphic Variants on Chinese Female Have Possible Association with Unexplained Recurrent Pregnancy Loss

Recurrent pregnancy loss (RPL) occurs frequently in Chinese patients, but the causes for 40-50% RPL remain unexplained. This study aims to explore possible association between recurrent pregnancy loss and chromosome polymorphism. We performed a retrospective cohort study including a total number of 2967 Chinese patients from January in 2013 to December in 2019.These participants were divided into two groups: group I (RPL group) and group II (control group). Group I included 1791 patients who underwent RPL. Group II included 1176 individuals who underwent primary infertility. Their chromosome karyotype analyses were performed by Giemsa banding protocol. Pearson chi-squared test and Fisher's exact test were employed to evaluate the difference in frequency of chromosomal polymorphic variations between both groups. Chromosomal polymorphism occurred more frequently in RPL group compared with control group, the differences for 9qh+, inv(9), and Yqh+ between both groups were (χ² = 6.697, p = 0.01), (χ² = 6.242, p = 0.012), and (χ² = 4.587, p = 0.032), respectively. The most significant difference of chromosomal polymorphism karyotype between RPL group and control group was found for acrocentric chromosome (D/G group) variants (χ² = 30.7, p < 0.001). Moreover, the difference in frequency of D/G group variants between women and men in RPL group was remarkably significant (χ² = 55.3, p < 0.001), and furthermore, D/G group variants occurred more frequently among women in RPL group than women in control group (χ² = 44.3, p < 0.001). We found that acrocentric chromosomal polymorphism occurred preferentially on Chinese women with RPL. The fascinating finding provides us novel insight into the potential association of higher frequency of acrocentric chromosomal variations on Chinese women with unexplained RPL.

Chromosomal polymorphisms associated with reproductive outcomes after IVF-ET

Purpose

This study aimed to investigate the effect of the detail type of chromosomal polymorphisms (1/9/16qh^+/−, D/G group polymorphisms, and inv(9)) on the IVF-ET outcomes.

Methods

A total of 1335 infertile couples undergoing IVF/ICSI were enrolled and comprehensively analyzed the correlation between three detail types of chromosomal polymorphisms (1/9/16qh^+/−, D/G group polymorphisms, and inv(9)) and the outcome of IVF/ICSI embryo transfer. The fertilized rate, cleaved embryo rate, good-quality embryo rate, clinical pregnancy rate, implantation rate, and early stage miscarriage rate were compared between the chromosomal polymorphisms groups and the control group.

Results

Both the inv(9) and D/G group chromosomal polymorphisms related to female infertility significantly lead to a lower 2PN cleavage rate (86.44% vs. 97.58% and 90.67% vs. 97.58%, respectively, P < 0.05) undergoing IVF insemination, the inv(9) adversely increasing the early miscarriage rate, either undergoing IVF (21.4% vs. 3.0%, P < 0.05) or ICSI (50.0% vs. 2.0%, P < 0.05) insemination, female carriers (23.08% vs. 2.87%, P < 0.05) or male carriers (44.44% vs. 2.87%, P < 0.05). For D/G groups, ICSI insemination may increase the implantation rate (44.8% vs. 23.69%, P < 0.05) and clinical pregnancy rate (78.6% vs. 40.65%, P < 0.05). 1/9/16qh^+/− had no apparent adverse effect on the patient’s clinical outcomes.

Conclusions

Our study suggests that chromosome karyotype analysis is necessary for IVF patients in clinical practice; we should afford individual genetic counseling suggestion according to the polymorphism types.

The incidence of long heterochromatic polymorphism variants in infants conceived through assisted reproductive technologies

Long heterochromatic variants on chromosomes 1, 9, 16 and Y are suspected to be implicated in infertility and early pregnancy loss, but little is known about how these variants are inherited in children conceived by infertile couples through assisted reproductive technologies. In this case-control study, the incidence of these variants was compared between infants conceived using intracytoplasmic sperm injection (ICSI), IVF and natural intercourse by karyotyping lymphocytes from cord blood or peripheral blood. This study included a total of 647 infants, including 189 conceived by ICSI, 177 by IVF, and 281 naturally conceived (NC). Variants were observed in 13.23% of ICSI, 15.82% of IVF and 12.46% of NC infants, showing that the incidence of variants does not appear to be significantly different between infants conceived using assisted reproductive technologies and infants conceived naturally. Because the parents of these infants were not karyotyped, we can only speculate as to whether these variants were directly inherited. This study concludes that infants born from infertile parents using assisted reproductive technologies to achieve pregnancy do not appear to be any more likely than NC infants of fertile parents to possess long heterochromatic variants.

Chromosomal polymorphisms are associated with female infertility and adverse reproductive outcomes after infertility treatment: a 7-year retrospective study

Data from 19,950 women were retrospectively analysed to determine the effect of chromosomal polymorphisms on female infertility and pregnancy outcome; fertile women were used as controls. Frequency of chromosomal polymorphisms and adverse pregnancy outcomes were compared between groups. A significantly higher incidence of chromosomal polymorphisms was found in total infertile patients, and patients with tubal infertility, ovulatory dysfunction, cervical and uterine abnormalities, and unexplained infertility compared with controls (5.53% [P < 0.001], 4.86% [P = 0.012] 5.40% [P < 0.001], 5.75% [P < 0.001] and 8.51% [P < 0.001], versus 3.74%, respectively). Infertile women had a higher incidence of 9qh+ and inv(9) compared with controls (P < 0.001 and P = 0.027). Logistic regression analysis showed an effect of chromosomal polymorphisms on female infertility (adjusted OR 1.662, 95% CI 1.551 to 1.796, P < 0.001). All couples reported a phenotypically normal baby. In control and tubal infertility groups, miscarriage rates were higher in women with chromosomal polymorphisms than in women with normal chromosomes (4.95% versus 0.96%, P = 0.001 and 6.17% versus 1.08%, P < 0.001). Preterm birth rate showed a similar trend. Chromosomal polymorphisms adversely affected spontaneous miscarriage rates (adjusted OR 1.625, 95% CI 1.514 to 1.769, P = 0.005).

The effect of chromosomal polymorphisms on the outcomes of fresh IVF/ICSI-ET cycles in a Chinese population

PURPOSE

Chromosomal polymorphisms (CPs) have been reported to be associated with infertility; however, their effects on the outcomes of in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) are still controversial. In this retrospective study, we aimed to evaluate the effect of CPs on IVF/ICSI-ET outcomes.

METHODS

To investigate whether CPs affected the outcomes of fresh IVF/ICSI-ET cycles in a Chinese population, we evaluated infertile couples with male carriers of CPs (n = 348), infertile couples with female carriers (n = 99), and unaffected couples (n = 400) who had received their first treatment cycles in our hospital between January 2013 and March 2015.

RESULTS

CPs in either male or female carriers seemed to have adverse effects on IVF/ICSI-ET outcomes. CPs in male carriers affected outcomes mainly by decreasing the rates of fertilization, embryo cleavage, good quality embryos, clinical pregnancies, ongoing pregnancies, and deliveries as well as increasing the biochemical pregnancy rate (P < 0.05); CPs in female carriers affected outcomes only by lowering the embryo cleavage rate (P < 0.05). The mean fertilization rate of couples with male CP carriers undergoing IVF was significantly lower than that in those undergoing ICSI (61.1 versus 66.5 %, respectively; P = 0.0004).

CONCLUSIONS

Our data provide evidence for the involvement of CPs in the poor outcomes of fresh IVF/ICSI-ET cycles in a Chinese population. The use of ICSI might improve outcomes by increasing the fertilization rate for men with CPs.

Pericentric Inversion of Human Chromosome 9 Epidemiology Study in Czech Males and Females

Pericentric inversion of human chromosome 9 [inv(9)] is a relatively common cytogenetic finding. It is largely considered a clinically insignificant variant of the normal human karyotype. However, numerous studies have suggested its possible association with certain pathologies, e.g., infertility, habitual abortions or schizophrenia. We analysed the incidence of inv(9) and the spectrum of clinical indications for karyotyping among inv(9) carriers in three medical genetics departments in Prague. In their cytogenetic databases, among 26,597 total records we identified 421 (1.6 %) cases of inv(9) without any concurrent cytogenetic pathology. This study represents the world's largest epidemiological study on inv(9) to date. The incidence of inv(9) calculated in this way from diagnostic laboratory data does not differ from the incidence of inv(9) in three specific populationbased samples of healthy individuals (N = 4,166) karyotyped for preventive (amniocentesis for advanced maternal age, gamete donation) or legal reasons (children awaiting adoption). The most frequent clinical indication in inv(9) carriers was "idiopathic reproductive failure" - 37.1 %. The spectra and percentages of indications in individuals with inv(9) were further statistically evaluated for one of the departments (N = 170) by comparing individuals with inv(9) to a control group of 661 individuals with normal karyotypes without this inversion. The proportion of clinical referrals for "idiopathic reproductive failure" among inv(9) cases remains higher than in controls, but the difference is not statistically significant for both genders combined. Analysis in separated genders showed that the incidence of "idiopathic reproductive failure" could differ among inv(9) female and male carriers.