A case-control study identifying chromosomal polymorphic variations as forms of epigenetic alterations associated with the infertility phenotype

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.

Effect of chromosomal polymorphisms on the outcome of in vitro fertilization and embryo transfer

PURPOSE

The incidence of chromosomal polymorphisms (CP) is increased in infertile couples, but its impact on reproduction is uncertain, especially undergoing assisted reproductive technology treatment. The purpose of the present study was to investigate the effect of CP on the outcomes of in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) treatment METHODS: A total of 1331 infertile couples undergoing IVF/ICSI treatment were involved in this retrospective case-control study. The participants were divided into 4 groups according to CP variations: (i) normal chromosomes (NC) group; (ii) CP group; (iii) both chromosomal polymorphisms (BCP) group; and (iv) double chromosomal polymorphisms (DCP) group. The CP group was further divided into five subgroups: qh+, D/G, inv(9), Yqh+ and Yqh-. The outcomes of IVF/ICSI-ET treatment were compared among the groups.

RESULTS

There were no differences observed between the eight groups in terms of number of oocytes retrieved, MII rate, fertilization rate, cleaved embryo rate, and quality embryo rate for both females and males (p > 0.05). In both male and female, some of the CP subgroups experienced more oocyte retrieval operations and more embryo transfer operations to achieve pregnancy than the NC groups (p < 0.05). The rates of live births were significantly lower in some of the CP subgroups compared to the NC group (p < 0.05).

CONCLUSION

In conclusion, the pregnancy outcomes of ET were affected by CP. It was speculated that this may be associated with the effect of chromosome polymorphism on embryo quality, although this could not be observed or determined by morphological evaluation.

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.

Segmental duplications and their variation in a complete human genome

Despite their importance in disease and evolution, highly identical segmental duplications (SDs) are among the last regions of the human reference genome (GRCh38) to be fully sequenced. Using a complete telomere-to-telomere human genome (T2T-CHM13), we present a comprehensive view of human SD organization. SDs account for nearly one-third of the additional sequence, increasing the genome-wide estimate from 5.4 to 7.0% [218 million base pairs (Mbp)]. An analysis of 268 human genomes shows that 91% of the previously unresolved T2T-CHM13 SD sequence (68.3 Mbp) better represents human copy number variation. Comparing long-read assemblies from human (n = 12) and nonhuman primate (n = 5) genomes, we systematically reconstruct the evolution and structural haplotype diversity of biomedically relevant and duplicated genes. This analysis reveals patterns of structural heterozygosity and evolutionary differences in SD organization between humans and other primates.

The Spectrum of Chromosomal Abnormalities and Endocrine Profile of Male Infertility with Nonobstructive Semen Abnormality: A Case-Control Study

Background:

Primary infertility is a common occurrence which affects approximately 15% of couples who desire to begin their family. Chromosomal abnormalities are well-established causes of pregnancy loss but may also have a role in explaining the cause of male infertility, especially with nonobstructive semen abnormalities. Hence, awareness regarding safety of artificial reproductive technology in these individuals due to underlying sperm aneuploidy is required.

Aims:

The aims of the study are to determine the prevalence of chromosomal abnormalities in primary infertile males with nonobstructive semen abnormalities and correlate with their endocrine profile.

Study Design:

A case–control study, in which 100 males with primary infertility and non-obstructive semen abnormalities were evaluated for chromosomal abnormality and hormonal profile; and were compared with 50 healthy males with normal semen analysis and at least one biological child.

Materials and Methods:

Blood T-lymphocytes were cultured using RPMI-1640 medium for obtaining metaphases and chromosomal analysis.

Statistical Analysis:

SPSS software and Student's t-test were used. A p < 0.05 was considered statistically significant.

Results:

Azoospermia (81%) was the most common nonobstructive semen abnormality. Overall prevalence of major chromosomal abnormalities and polymorphic variants was 16% and 7%, respectively. Klinefelter syndrome was the most common sex chromosomal numerical abnormality seen in 6.17% of cases with azoospermia. All healthy control males had 46, XY karyotype. Higher levels of follicle-stimulating hormone and luteinizing hormone and lower levels of testosterone along with testicular volumes were observed in infertile males with abnormal karyotype (p < 0.05).

Conclusion:

Primary infertile males with nonobstructive semen abnormality have high frequency of chromosomal aberrations, which justify the requirement of cytogenetic testing in these patients.

Analysis of the clinical features of pericentric inversion of chromosome 9

Objective

The pericentric inversion of chromosome 9 (inv9) is one of the most common structural balanced chromosomal variations, and it is considered to be a normal population variant. The aim of this study was to re-evaluate the clinical impact of patients with inv9.

Methods

We studied the karyotypes from 4853 patients at a single center and retrospectively reviewed their clinical data.

Results

There were 67 inv9 patients among 2988 adults, and 62 of them showed different clinical features, including male and female infertility, oligoasthenozoospermia, and azoospermia. Thirty-one cases of inv9 were found in 1865 fetuses, including two cases in chorionic villus (6.90%) and 29 in amniotic fluid (1.67%), but there were no cases in umbilical cord blood. The rates of fetal phenotype abnormal and adverse pregnancy outcome with inv9 in the chorionic villus were 100.00% (2/2), while only 17.24% (5/29) in the amniotic fluid showed abnormalities, among which 60.00% (3/5) had adverse pregnancy outcomes.

Conclusions

Although there is no clear evidence that inv9 is pathogenic, the genetic counseling on inv9 in early pregnancy and adults needs to be given more attention.

A case–control study identifying the frequency and spectrum of chromosomal anomalies and variants in a cohort of 1000 couples with a known history of recurrent pregnancy loss in the Eastern region of India

Background:

Recurrent pregnancy loss (RPL) is a common occurrence that affects up to 15% of couples in their reproductive years. In both males and females with RPL and infertility, chromosomal abnormalities play a significant impact.

Aim:

The study was designed to examine the involvement of chromosomal anomalies and the frequency of certain chromosomal variants persistent among couples experiencing RPL.

Setting and Design:

This case–control study was conducted on 1000 couples from January 2015 to September 2020 in the state of Odisha, India, strictly adhering to principles of Helsinki Declaration (1975). The study was performed at the School of Biotechnology, KIIT University in collaboration with inDNA Life Sciences Private Limited.

Materials and Methods:

A cohort of 1148 individuals with a history of RPL were selected for the study and they were screened with respect to fertile controls for the presence of any chromosomal anomaly using G-banding, nucleolar organizing region (NOR)-banding and fluorescence in situ hybridisation wherever necessary.

Statistical Analysis:

The connection between distinct polymorphic variations and the occurrence of RPL was assessed using Fisher's exact test. Significant was defined as a P ≤ 0.005.

Results:

One hundred and thirty-four individuals were found to harbor chromosomal anomalies. This study elucidates that along with balanced chromosomal translocations, the involvement of polymorphic variants also plays a significant role in cases of RPL.

Conclusion:

The cumulative occurrence of chromosomal anomalies and variants across our cohort of 1148 individuals indicates that the chromosomal assessment of all couples experiencing RPL must be performed by all the clinicians. This study aids us in identifying chromosomal polymorphisms as major players of RPL in addition to novel chromosomal translocations.

Clinical Manifestations of Chromosomal Anomalies and Polymorphic Variations in Patients Suffering from Reproductive Failure

Background:

Human reproduction is the most intricate event as ~ 20% of human pregnancies end in miscarriages for which chromosomal anomalies are a common factor. The chromosomal variations associated with reproductive failures include translocations, inversions, supernumerary marker chromosomes, heterochromatic polymorphisms, etc., Till date, the significance of heteromorphic variants in reproductive failures is unclear.

Aim:

The aim of this study is to investigate the role of chromosomal anomalies and polymorphic variations in reproductive failure.

Materials and Methods:

Chromosomal analysis using GTG banding was performed on 638 couples (1276 individuals).

Results:

In the present study, 138 of 1276 individuals showed chromosomal variations with respect to heterochromatic variants and Robertsonian translocations. The most common variants observed across the population studied were the pericentric inversion of the chromosome 9 [inv(9)(p11q13), 3.68%] followed by pstk + on the short arm of chromosome 15 (15pstk+, 1.95%) and Robertsonian translocation of chromosomes 13 and 14 [rob(13;14)(q10;q10), 1.25%]. The maximum percentage of heterochromatic variation was observed in females with recurrent pregnancy loss (Groups A, 4.78%) and males with wives having recurrent miscarriages (Group B, 3.68%) and the minimum was recorded in patients with in vitro fertilization (IVF) failures (Group C, 0.23%) and couples having a history of the malformed child (Group F, 0.23%).

Conclusions:

High level of chromosomal polymorphic variations in patients with reproductive failures warrants their in-depth analysis to nail down the causative factors. Hence, cytogenetic analysis coupled with genetic counseling becomes indispensable for patients suffering from infertility, reproductive failures and pregnancy losses before IVF treatment to rule out the carrier status.

Cytogenetic Analysis of 570 Couples with Recurrent Pregnancy Loss: Reporting 11 Years of Experience

Objectives

Recurrent pregnancy loss (RPL) is a serious complication of pregnancies, affecting almost 2%-5% of couples. Among numerous underlying causes, chromosomal anomalies in one of the partners are regarded as important issues, with varying frequencies among different populations. In this study, we aimed to determine the prevalence of chromosomal abnormalities and chromosome polymorphisms in couples with a history of RPL from Kermanshah province, west of Iran.

Materials and Methods

In this 11-year retrospective study, a total of 1140 cases with two or more spontaneous abortions were recruited and studied according to standard cytogenetic analysis.

Results

From a total of 1140 reviewed blood samples, 1011 people (88.5%) had a normal karyotype and 129 people (11.5%) had chromosomal aberrations. These aberrations were found in 62 females and 67 males. The prevalence of chromosomal abnormalities was as follows: 18 (1.5%) structural aberrations, 1 numerical anomaly and 110 (9.6%) apparently normal polymorphic variants.

Conclusions

Our findings could determine the underlying cause of RPL in 1.5% of the population while the majority still remained unexplained. This emphasizes the importance of searching for other genetic and nongenetic causes of RPL in apparently idiopathic cases of RPL.

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.

Clinical outcomes of Preimplantation genetic testing (PGT) application in couples with chromosomal inversion, a study in the Chinese Han population

BACKGROUND

Chromosomal inversion was considered to have adverse effects on pregnancy outcomes through abnormal gametogenesis. The purpose of this retrospective study was to investigate whether preimplantation genetic testing (PGT) improves pregnancy outcomes for couples with chromosomal inversion.

METHODS

A total of 188 cycles from 165 couples with one chromosomal inversion carrier were divided into two groups: PGT (136 cycles, 125 couples) and non-PGT (52 cycles, 50 couples). Biochemical pregnancy, clinical pregnancy, ongoing pregnancy, miscarriage and live birth rates of their first transfer cycles, as well as cumulative live birth rates of each cycle and euploidy rates, were analyzed.

RESULTS

There were no statistically significant differences in the pregnancy outcomes between the two groups. The euploidy rate of pericentric inversion carriers was not higher than that of paracentric inversion carriers in PGT group (60.71% vs 50.54%, P = 0.073). Similarly, the euploid rate of male carriers was not higher than that of female carriers (61.2% vs 56.1%, P = 0.256).

CONCLUSIONS

Due to limitation of retrospective study and small sample size, our current data showed that PGT cannot provide prominent benefits for inversion carriers in the Chinese Han population. Further prospective randomized controlled trials are needed to evaluate the effects of PGT.

[Chromosomal polymorphisms are associated with blastomere multinucleation in IVF/ICSI cycles]

OBJECTIVE

To investigate the association of chromosomal polymorphisms with multinucleated embryos in infertile couples undergoing in vitro fertilization-intracytoplasmic sperm injection (IVF-ICSI).

METHODS

This retrospective case-control study was conducted among 1145 infertile couples undergoing their first IVF/ICSI cycles. According to their karyotype, the couples were divided into chromosomal polymorphism group and control group, and the former group was divided into 3 subgroups: inversion group, D and G genome polymorphic group and 1, 9, and 16 qh+group. The blastomere multinucleation rate, clinical pregnancy rate and live birth rate were compared between the groups.

RESULTS

Of the total of 1145 couples, 139 (6.10%) had chromosomal polymorphisms at least in one partner. No significant differences were found in female age, BMI, basal FSH level, total gonadotropin dose, E₂ level on day of HCG, number of oocytes retrieved, fertilization rate, top quality embryo rate, clinical pregnancy rate or live birth rate among the groups (P > 0.05). The multinuclear rate of the embryos in couples with pericentric inversion of chromosomes 1, 9, and Y chromosomes and those with D and G genome polymorphisms were 8.23% and 4.65%, respectively, significantly higher than that in the control group (2.69%; P < 0.05); the multinuclear rate of the embryos was 2.77% in 1, 9, and 16 qh+ group, similar with that in the control group (P > 0.05).

CONCLUSIONS

Infertile couples with pericentric inversion of chromosomes 1, 9, and Y chromosomes and in those with D and G genome polymorphism are at higher risks of blastomere multinucleation in IVF- ICSI cycles; 1, 9, and 16 qh + polymorphisms do not increase the rate of blastomere multinucleation of the embryos.

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 association between the two more common genetic causes of spermatogenic failure: a 7-year retrospective study

Chromosomal abnormalities and Y chromosome microdeletions are considered to be the two more common genetic causes of spermatogenic failure. However, the relationship between chromosomal aberrations and Y chromosome microdeletions is still unclear. This study was to investigate the incidence and characteristics of chromosomal aberrations and Y chromosome microdeletions in infertile men, and to explore whether there was a correlation between the two genetic defects of spermatogenic failure. A 7-year retrospective study was conducted on 5465 infertile men with nonobstructive azoospermia or oligozoospermia. Karyotype analysis of peripheral blood lymphocytes was performed by standard G-banding techniques. Y chromosome microdeletions were screened by multiplex PCR amplification with six specific sequence-tagged site (STS) markers. Among the 5465 infertile men analyzed, 371 (6.8%) had Y chromosome microdeletions and the prevalence of microdeletions in azoospermia was 10.5% (259/2474) and in severe oligozoospermia was 6.3% (107/1705). A total of 4003 (73.2%) infertile men underwent karyotyping; 370 (9.2%) had chromosomal abnormalities and 222 (5.5%) had chromosomal polymorphisms. Karyotype analysis was performed on 272 (73.3%) patients with Y chromosome microdeletions and 77 (28.3%) had chromosomal aberrations, all of which involved sex chromosomes but not autosomes. There was a significant difference in the frequency of chromosomal abnormalities between men with and without Y chromosome microdeletions (P < 0.05).

Co-occurrences of polymorphic heterochromatin regions of chromosomes and effect on reproductive failure

Although the polymorphic heterochromatin regions of chromosomes (heteromorphisms) have been extensively studied for their phenotypic effects on humans, co-occurrences of chromosome 1, 9, 16 and Y heteromorphisms and of acrocentric variants have never been studied on humans with an objective scoring system. Here we compared the frequencies of individual heteromorphisms on a total of 602, 768 and 224 patients with the indications of infertility, recurrent miscarriage and in vitro fertilization (IVF) failure, respectively and on 272 controls. Then we examined whether there were significant co-occurrences between heteromorphisms within and between the groups. There were no statistically significant differences in the frequencies of heteromorphisms between the groups. Both statistically significant and non-significant correlations were observed within the non-acrocentric and certain acrocentric heteromorphisms in each group. When these co-occurrences were examined between the groups, a 2.2 fold increased risk of IVF failure in males in the presence of either chromosome 13 or chromosome 21 variants was observed (95 %CI:1.1-4.2). We conclude that the simultaneous manifestations of heteromorphisms have no effect on reproductive failure. There seems to be a correlation between the non-acrocentric heteromorphisms (1qh+, 9qh+, 16qh + and Yqh+/-), which might be the result of complex interactions of formation of these heterochromatin regions. The correlations observed between certain acrocentric chromosomes might be related to satellite association and nucleolus formation. The increased risk observed in males with IVF failure in the presence of either chromosome 13 or 21 variants should be interpreted cautiously due to the heterogeneity of the group.

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

BACKGROUND

Detection of chromosomal abnormalities is crucial in various medical areas; to diagnose birth defects, genetic disorders, and infertility, among other complex phenotypes, in individuals across a wide range of ages. Hence, the present study wants to contribute to the knowledge of type and frequency of chromosomal alterations and polymorphisms in Ecuador.

METHODS

Cytogenetic registers from different Ecuadorian provinces have been merged and analyzed to construct an open-access national registry of chromosome alterations and polymorphisms.

RESULTS

Of 28,806 karyotypes analyzed, 6,008 (20.9%) exhibited alterations. Down syndrome was the most frequent autosome alteration (88.28%), followed by Turner syndrome (60.50%), a gonosome aneuploidy. A recurrent high percentage of Down syndrome mosaicism (7.45%) reported here, as well as by previous Ecuadorian preliminary registries, could be associated with geographic location and admixed ancestral composition. Translocations (2.46%) and polymorphisms (7.84%) were not as numerous as autosomopathies (64.33%) and gonosomopathies (25.37%). Complementary to conventional cytogenetics tests, molecular tools have allowed identification of submicroscopic alterations regions or candidate genes which can be possibly implicated in patients' symptoms and phenotypes.

CONCLUSION

The Ecuadorian National Registry of Chromosome Alterations and Polymorphisms provides a baseline to better understand chromosomal abnormalities in Ecuador and therefore their clinical management and awareness. This data will guide public policy makers to promote and financially support cytogenetic and genetic testing.

Effects of chromosome 9 inversion on IVF/ICSI: A 7-year retrospective cohort study

Background

This study focused on the outcomes of patients with pericentric inversion of chromosome 9 who underwent IVF/ICSI and fresh day 2 or day 3 embryo transfer and the possible impacts of carrier gender and chromosome karyotype on pregnancy outcomes.

Methods

A total of 214 couples (107 couples with one pericentric inversion of chromosome 9 in one partner [Group 1], 107 couples with normal karyotypes [Group 2]) underwent their first IVF/ICSI treatment and were included in this study. Oocyte number, normal fertilization rates, abnormal fertilization rates, cleavage rates, embryo utilization rates, fresh embryo transfer rates, clinical pregnancy rates (CPR), implantation rates, miscarriage rates, and live birth rates per embryo transfer (LBR) were compared between groups.

Results

Group 1 did not show any disadvantage when compared with Group 2. The CPR and LBR were similar between all groups. The female carrier group had a higher normal fertilization rate and higher utilization rate than the male carrier group. Cases with inv(9)(p12;q13) had a lower utilization rate but a higher implantation rate than the remaining karyotypes.

Conclusion

In the first IVF or ICSI cycle, couples with one pericentric inversion of chromosome 9 in one partner had satisfactory outcomes. The subgroup analysis showed a tendency of better prognosis for the female carrier and inv(9)(p12;q13) type.

This is a retrospective cohort study during 7 years period. In the first IVF or ICSI cycle, couples with one pericentric inversion of chromosome 9 in one partner had satisfactory outcomes. The subgroup analysis showed a tendency of better prognosis for the female carrier and inv(9)(p12;q13) type.

Chromosomal Aberrations in Couples with Pregnancy Loss: A Retrospective Study

BACKGROUND

Recurrent pregnancy loss is a challenging reproductive problem, and chromosomal anomalies approximately affect 2%-8% of couples with recurrent pregnancy loss. The chromosomal abnormality, especially balanced translocation rearrangement in either parent, is the important cause of recurrent spontaneous abortion.

AIMS

The aim of this study was to investigate the role and prevalence of chromosomal anomalies in recurrent miscarriages. The results will be helpful for counseling and make the decision for alternative options and precaution for the affected couples and also support to make a national database.

SETTINGS AND DESIGN

The present retrospective study was carried out in 172 couples (344 individuals) having the history of three or more recurrent spontaneous abortion. The cytogenetic analysis was done in all 344 individuals using G-banding and karyotyping.

RESULTS

Out of 172 couples, 17 couples (9.88%) had different types of structural or numerical chromosomal abnormalities. The structural aberrations were observed in 15 (8.72%) couples, and numerical aberrations were seen in 2 (1.16%) couples. Out of 17 couples, 8 (47.05%) had balanced translocations, 2 (11.76%) had the Robertsonian translocation, 5 (29.41%) had the pericentric inversion of chromosome 8, 9, and Y, and only 2 (11.76%) women showed sex chromosome numerical aberrations.

CONCLUSIONS

Cytogenetic analysis should be an important routine investigation in couples with repeated miscarriages. Cytogenetic analysis is essential and helpful for genetic counseling to take precaution and implementing proper reproductive alternatives. Studies on the genetic basis of pregnancy loss should be taken up to generate data on these issues from different regions.

Chromosomal abnormalities in recurrent miscarriages by conventional karyotyping analysis

Abstract Objectives: to describe the prevalence and types of chromosomal abnormalities in couples with recurrent miscarriage and products of conception. Methods: electronic searches were performed in the PubMed/Medline database and in the Portal Regional da Biblioteca Virtual em Saúde/BVS (Regional Website of the Virtual Library in Health/BVS) using the descriptors “chromosomal abnormalities and abortions and prevalence”. After applying the inclusion and exclusion criterias, 17 studies were selected. Results: 11 studies were conducted in couples with recurrent miscarriage and six in products of conception. The main results of the couples with recurrent miscarriage were: the frequency of chromosomal abnormalities which varied from 1.23% to 12% and there was a predominance alteration of the chromosomal structures (reciprocal translocations, followed by Robertsonian). In products of conception, the results observed were: the frequency of chromosomal abnormality was above 50% in approximately 70% of the studies; there was a predominance alteration of the numerical chromosomal (trisomy - chromosomes 16, 18, 21 and 22, followed by polyploidy and monosomy X). Conclusions: in summary, cytogenetic alterations represent an importante cause of pregnancy loss and its detection can help couples with genetic counseling. Therefore, the value of knowledge on the prevalence of cytogenetic abnormalities in miscarriage samples is unquestionable, once it is permitted a proper genetic counseling for the couple.

The synergic effects of CTLA-4/Foxp3-related genotypes and chromosomal aberrations on the risk of recurrent spontaneous abortion among a Chinese Han population

The current study was aimed to investigate the association of CLTA-4/Foxp3 polymorphisms and chromosomal abnormalities with recurrent spontaneous abortion (RSA) risk in a Chinese Han population. Altogether, 1284 RSA women and 1046 women with normal pregnancy were incorporated in this study. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was implemented to genotype the single-nucleotide polymorphisms (SNPs) located within CTLA4 and Foxp3. Moreover, the cytogenetic diagnosis was performed in line with the standards of G banding karyotype. As a consequence, rs231775 and rs3087243 of CTLA4, as well as rs2232365 and rs2232368 of Foxp3, all appeared to modify the risk of RSA. Besides, significant differences were found between the ratio of structural abnormality and that of numerical abnormality (P < 0.038), and chromosome abnormality was associated with higher miscarriage frequency (>3) than normal karyotypes. Of note, the synergic effects of the genotypes and chromosomal abnormality all tallied with the sub-multiplication model (ORchromosome × ORSNP > ORchromosome+SNP), while rs2232365 GG and chromosomal aberration impacted the RSA risk in a super-multiplicative way that ORchromosome × ORSNP < ORchromosome+SNP. In conclusion, susceptibility to RSA was subject to the synthetic regulation of chromosomal aberrations and genetic mutations within CLTA-4 and Foxp3, suggesting that the conduction of karyotype analysis and genetic detection for RSA patients could effectively guide effective RSA counseling and sound child rearing.

Prevalence of Cytogenetic Anomalies in Couples with Recurrent Miscarriages: A Case-control Study

Background:

About 15%–20% of couples get affected by recurrent miscarriages (RM) and chromosomal abnormality in one partner affects 3%–6% of RM couples.

Aims:

The present study aimed to determine the prevalence of cytogenetic anomalies in couples with RM.

Settings and Design:

A case–control study was undertaken, in which 243 couples who had experienced 2 or >2 miscarriages were investigated for chromosomal abnormalities and compared with 208 healthy, age-matched control couples who had at least one healthy live born and no history of miscarriages.

Material and Methods:

Peripheral blood (PB) lymphocytes were cultured using PB-Max Karyotyping medium (GIBCO) for chromosomal analysis and 20 metaphases were analyzed for each individual.

Statistical Analysis:

Student's t-test was used for statistical evaluation and P < 0.05 was considered statistically significant for all instances.

Results:

The current study revealed 3.1% RM cases showing structural chromosomal aberrations, of which balanced translocations and Robertsonian translocations constituted 66.7% and 26.7% cases, respectively, while inversions constituted 6.7% abnormal RM cases. Polymorphic variations were observed in 1.9% RM patients and 1.2% controls as well. However, the number of abortions were significantly more (P = 0.027) in male carriers of balanced translocations as compared to female carriers in the RM group. There was no significant difference for age (P = 0.539) between RM women and control women.

Conclusions:

Although similar studies exist in literature, our study is the first of its kind from our region that has compared the chromosomal anomalies between the RM group and the control group. We observed 3.1% of balanced translocations and an increased number (though nonsignificant) of polymorphic variations and satellite associations in the RM group as compared to the control group.

Chromosomal polymorphisms are independently associated with multinucleated embryo formation

PURPOSE

The purpose of this study is to explore the factors associated with embryo multinucleation, particularly focused on the influence of parental chromosomal polymorphisms in embryo multinucleation.

METHODS

This is a retrospective case-control study involving 1260 infertile couples undergoing their first IVF/ICSI cycles. Couples were screened for abnormalities in their karyotype and were evaluated for blastomere persistence of multinucleation. Demographic characteristics, stimulation protocol, and pregnant outcomes were analyzed using logistic regression analysis.

RESULTS

The level of basal FSH was lower in the multinucleated embryos group (5.37 vs 5.72 IU/L). The Multinucleated embryos group received less gonadotropins (1788.5 vs 1891.3 IU), and the level of LH on day of HCG triggering was lower (1.09 vs 1.30 IU/L). More oocytes were recovered in the multinucleated embryos group (11.51 vs 9.23). Chromosomal polymorphisms were seen in at least 1 out of 163 (12.9%) couples. Multivariate logistic regression analysis revealed that chromosomal polymorphisms were independently associated with an increase in the occurrence risk of multinucleated embryos (OR = 1.61, 95% CI, 1.06-2.44) in the first IVF/ICSI cycle. The miscarriage rate in the multinucleated embryos group was 10% higher than that of the control group.

CONCLUSIONS

Chromosomal polymorphisms were independently associated with multinucleation embryo formation. A higher LH level on the day of HCG triggering was associated with a decreased chance of multinucleation.

Male chromosomal polymorphisms reduce cumulative live birth rate for IVF couples

PURPOSE

Chromosomal polymorphisms are associated with infertility, but their effects on assisted reproductive outcomes are still quite conflicting, especially after IVF treatment. This study evaluated the role of chromosomal polymorphisms of different genders in IVF pregnancy outcomes.

METHODS

Four hundred and twenty-five infertile couples undergoing IVF treatment were divided into three groups: 214 couples with normal chromosomes (group A, control group), 86 couples with female polymorphisms (group B), and 125 couples with male polymorphisms (group C). The pregnancy outcomes after the first and cumulative transfer cycles were analyzed, and the main outcome measures were live birth rate (LBR) after the first transfer cycle and cumulative LBR after a complete IVF cycle.

RESULTS

Comparison of pregnancy outcomes after the first transfer cycle within group A, group B, and group C demonstrated a similar LBR as well as other rates of implantation, clinical pregnancy, early miscarriage, and ongoing pregnancy (P > 0.05). However, the analysis of cumulative pregnancy outcomes indicated that compared with group A, group C had a significantly lower LBR per cycle (80.4 vs 68.00%), for a rate ratio of 1.182 (95% CI 1.030 to 1.356, P = 0.01) and a significantly higher cumulative early miscarriage rate (EMR) among clinical pregnancies (7.2 vs 14.7%), for a rate ratio of 0.489 (95% CI 0.248 to 0.963, P = 0.035).

CONCLUSION

Couples with chromosomal polymorphisms in only male partners have poor pregnancy outcomes after IVF treatment manifesting as high cumulative EMR and low LBR after a complete cycle.

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).

Chromosomal polymorphic variants increase aneuploidies in male gametes and embryos

Chromosomal polymorphisms involve heterochromatic regions and occur in the general population. However, previous studies have reported a higher incidence of these variants in infertile patients. The aim of this study was to examine the relationship between polymorphic variants and infertility and their association with aneuploidies in male gametes and embryos. We retrospectively considered 1,551 cytogenetic studies involving infertile patients (study group; n=866) and oocyte/sperm donors as the control group (n=685). We had detected 168 polymorphisms in the study group and 92 in the control group. An increase in the frequency of polymorphic variants was observed among infertile patients (19.4% study group vs. 13.4% control group; P < 0.01). Sperm aneuploidies among 145 infertile men were evaluated by fluorescent in situ hybridization (FISH). The frequency of infertile men with increased rates of sperm aneuploidy was higher among polymorphism carriers. Twenty men showed an abnormal rate of sperm aneuploidy in the carrier group (n=53) vs. 15 in the non-carrier group (n=92) (37.7% vs. 16.3%, respectively; P < 0.01). Finally, aneuploidies in blastocysts (n=301) resulting from donated oocytes were also examined by array comparative genomic hybridization (array-CGH). Significant differences were reported in the embryo aneuploidy rate between female carriers and non-carriers in oocyte donation cycles (50.0% vs. 27.6%; P < 0.001). This study suggests that polymorphic variants have an impact on fertility. Moreover, our results show a relationship between polymorphisms and aneuploidy in spermatozoa and embryos.

ABBREVIATIONS

FISH: fluorescent in situ hybridization; CGH: comparative genomic hybridization; ESHRE: European Society of Human Reproduction and Embryology; ASRM: American Society for Reproductive Medicine; RPL: recurrent pregnancy loss; WHO: World Health Organization; ISCN: International System for Human Cytogenetic Nomenclature guidelines; WGA: whole genome amplification; SPSS: Statistical Package for Social Sciences.

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.

Chromosomal Abnormalities in Infertile Men from Southern India

BACKGROUND AND OBJECTIVE

Male infertility has been associated with aneuploidies and structural chromosomal abnormalities, Yq microdeletions and specific gene mutations and/or polymorphisms. Besides genetic factors, any block in sperm delivery, endocrine disorders, testicular tumours, infectious diseases, medications, lifestyle factors and environmental toxins can also play a causative role. This study aimed to determine the constitutional karyotype in infertile males having normal female partners in a south Indian population.

MATERIALS AND METHODS

A total of 180 men with a complaint of primary infertility ranging from 1 to 25 years were screened for chromosomal abnormalities through conventional analysis of GTG-banded metaphases from cultured lymphocytes.

RESULTS

Four individuals were diagnosed to have Klinefelter syndrome. Two cases exhibited reciprocal translocations and one showed a maternally inherited insertion. Polymorphisms were seen in sixty-seven patients (37.2%).

CONCLUSION

The occurrence of chromosomal abnormalities in 4.6% and variants involving the heterochromatic regions of Y, chromosome 9 and the acrocentric chromosomes in 38.2% of the infertile men with an abnormal seminogram strongly reiterates the inclusion of routine cytogenetic testing and counselling in the diagnostic work-up prior to the use of assisted reproduction technologies.

Chromosomal aberrations and polymorphic evaluation in males with primary infertility from Indian population

BACKGROUND AND OBJECTIVES

The chromosomal abnormalities are one of the important causes of male infertility. In view of the genetic risks for the next generation, the importance of careful evaluation of karyotype is essential. The objective of this study was to determine the frequency of chromosomal abnormalities in infertile men with primary infertility from Indian population.

MATERIALS AND METHODS

The 78 infertile men with primary infertility, out of which 26 men were azoospermic, 19 men were oligospermic, 4 men were asthenospermic and 29 men were oligoasthenospermic were studied. Karyoptying was performed on peripheral blood lymphocytes by using the Giemsa trypsin banding (GTG) banding technique. Additional data was collected from published studies in Indian population leading to a total of 1814 cases.

RESULTS

Chromosome analysis of 78 infertile males showed major chromosome abnormalities in 10.2%, with 6.4% in autosomal chromosome abnormalities and 3.8% in sex chromosome abnormalities. The incidence of major chromosome abnormalities in oligospermic males were 21% and azoospermic males were 15.4 %. Chromosomal polymorphic variants were identified to be 16.7%. Combining the data from other published studies identified 153/ 1814 (8.4%) infertile men of chromosomal abnormalities; with 10.8% in azoospermia, 7.3% in oligospermia and 7.3% in oligoasthenoteratospermic from India.

INTERPRETATION AND CONCLUSION

The overall high prevalence of chromosomal abnormalities in infertile males suggests that the conventional chromosomal analysis is an important investigative tool for male infertility, especially prior to use of any assisted reproductive techniques.

Effect of chromosomal polymorphisms of different genders on fertilization rate of fresh IVF-ICSI embryo transfer cycles

To explore whether chromosomal polymorphisms of different genders affect outcomes of fresh IVF and intracytoplasmic sperm injection (ICSI) embryo transfer cycles differently, 37 couples with chromosomal polymorphisms were identified out of 614 infertile couples undergoing IVF-ICSI treatments. Group 1 included 20 couples in which only the male carried chromosomal polymorphisms; group 2 included 17 couples with female carriers only; group 3 included 19 infertile couples with normal karyotypes randomly selected as controls. A significantly lower fertilization rate was found in group 1 compared with groups 2 and 3 (56.68% in Group 1, 78.02% in group 2 and 71.74% in group 3; group 1 versus group 2, P < 0.001; group 1 versus group 3, P = 0.001; respectively). When stratified according to fertilization method, the fertilization rate in IVF cycles of group 1 was significantly lower than group 3 (50.00% in Group 1, 73.89% in Group 3, P < 0.001). Fertilization rates in ICSI cycles between groups 1 and 3 were not significantly different. This study suggests that male chromosomal polymorphisms adversely influence fertilization rates of IVF cycles. The use of ICSI may improve the success of infertility treatment by increasing the fertilization rate for men with chromosomal polymorphisms.

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

Heterochromatin variants are commonly found during cytogenetic examinations, and chromosomes 1, 9, 16 and Y are commonly involved in these variations. These variants are believed to be clinically insignificant variations in human karyotypes. Nevertheless, reproductive failure has been frequently discussed as possibly being associated with these variants. Various authors have reported a significantly elevated incidence of these variants in individuals with idiopathic reproductive failure compared with individuals with no such history. This study compared the incidence of heterochromatin variants in individuals with idiopathic reproductive failure (n=1036) with that of a control group of healthy fetuses (n=995) indicated for prenatal karyotype examination solely based on the advanced ages of their mothers. The heterochromatin variants occurred more frequently in the reproductive failure group than in the controls (P=0.006). Regarding individual chromosomes, chromosome 9 variants were most frequently found in the study and control groups, and they also occurred more frequently in the reproductive failure group. The most significant difference between the study and control groups was found for the 9qh+ variant (P=0.026), and although the results are statistically significant, the cause of this phenomenon remains unknown.

Ovulation induction and epigenetic anomalies

In this systematic review of ovulation induction and epigenetic control, studies mainly done in the mouse model highlight how hormone treatments may be prejudicial to the epigenetic reprogramming of gametes as well as early embryos. Moreover, the hormone protocols used in assisted reproduction may also modify the physiologic environment of the uterus, a potential link to endometrial epigenetic disturbances. At present, the few available data in humans are insufficient to allow us to independently determine the impact of a woman's age and infertility problems and treatment protocols and hormone doses on such processes as genomic imprinting.

Heteromorphic variants of chromosome 9

Background

Heterochromatic variants of pericentromere of chromosome 9 are reported and discussed since decades concerning their detailed structure and clinical meaning. However, detailed studies are scarce. Thus, here we provide the largest ever done molecular cytogenetic research based on >300 chromosome 9 heteromorphism carriers.

Results

In this study, 334 carriers of heterochromatic variants of chromosome 9 were included, being 192 patients from Western Europe and the remainder from Easter-European origin. A 3-color-fluorescence in situ hybridization (FISH) probe-set directed against for 9p12 to 9q13~21.1 (9het-mix) and 8 different locus-specific probes were applied for their characterization. The 9het-mix enables the characterization of 21 of the yet known 24 chromosome 9 heteromorphic patterns. In this study, 17 different variants were detected including five yet unreported; the most frequent were pericentric inversions (49.4%) followed by 9qh-variants (23.9%), variants of 9ph (11.4%), cenh (8.2%), and dicentric- (3.8%) and duplication-variants (3.3%). For reasons of simplicity, a new short nomenclature for the yet reported 24 heteromorphic patterns of chromosome 9 is suggested. Six breakpoints involved in four of the 24 variants could be narrowed down using locus-specific probes.

Conclusions

Based on this largest study ever done in carriers of chromosome 9 heteromorphisms, three of the 24 detailed variants were more frequently observed in Western than in Eastern Europe. Besides, there is no clear evidence that infertility is linked to any of the 24 chromosome 9 heteromorphic variants.

Karyotype analysis in large-sample infertile couples living in Central China: a study of 14965 couples

OBJECTIVE

To explore that it is necessary to routinely detect chromosomes in fertile couples, we detected peripheral blood lymphocyte karyotype in 14965 infertile couples living in Central China and analyzed the incidence and type of chromosomal anomaly.

METHODS

G-banding karyotype analysis of peripheral blood lymphocytes was performed in 14965 couples who went to the outpatient department of our reproductive medical center for counseling on infertility between January 2004 and December 2011. Semen analysis was performed three times in all the men from the 14965 couples.

RESULTS

The rate of chromosomal anomaly in the 14965 infertile couples was 3.84 % (1150/29930). The rate of chromosomal anomaly in the men from 14965 couples was 6.84 % (1024/14965) and in the women 0.84 % (126/14965). The rates of chromosomal anomaly were 1.69 % in normal semen group, 11.82 % in light oligo-astheno-spermis group, 6.58 % in moderate to severe olig-astheno-spermia group and 17.26 % in azoospermia group.

CONCLUSION

Since the rates of chromosomal anomaly are 1.69 % and 11.82 % even in normal semen group and light oligo-astheno-spermia group, respectively, it is necessary to detect peripheral blood lymphocyte karyotype in all infertile couples.

Impact of chromosomal heteromorphisms on reproductive failure and analysis of 38 heteromorphic pedigrees in Northeast China

Purpose

To compare the frequency of chromosomal heteromorphisms in reproductive failure and fertile control individuals in Northeast China, and investigate the impact on reproductive failure

Methods

1751 males and 1424 couples with reproductive failure (n = 4599) and 777 fertile control individuals in Northeast China were enrolled. Chromosome karyotype analysis was performed on peripheral blood lymphocytes with standard G-banding. Additionally, C-banding was performed with heterochromatin heteromorphisms, and NORs-banding with satellites/stalks variations. Multiplex polymerase chain reaction (PCR) adopted for the amplification using nine specific sequence tagged sites (STS) were used to detect Y-chromosome microdeletions with Y chromosome variations (Yqh±). At the same time, 38 heteromorphic probands’ family members were recalled for performing karyotype analysis and to be surveyed for their detailed reproductive history.

Results

The frequency of chromosomal heteromorphisms in reproductive failure patients (2.74 %, 126/4599) was of no statistically significant difference as compared with fertile control individuals (2.06 %, 16/777) (P > 0.05). Eight cases of Y variation (Yqh±) probands with Y-chromosomal microdeletions were detected among 44 reproductive failure patients and 6 fertile control men. In the 38 recalled families, the probands of fathers or mothers, even some of their brothers or sisters, had the same heteromorphic karyotypes as probands’ despite that they didn’t have any adverse reproductive history.

Conclusions

There was no statistically significant difference in frequency of chromosomal heteromorphisms between reproductive failure and fertile control individuals in Northeast China. Males with Y variations (Yqh±) should be ordered Y-chromosomal microdeletions detection. Through the analysis of 38 recalled families, we can also conclude that chromosomal heteromorphisms were not the impact factors for reproductive failure.

A preliminary study of the relationship between the long arm of the Y chromosome (Yqh+) and reproductive outcomes in IVF/ICSI-ET

OBJECTIVE

To compare the reproductive outcomes of Yqh+-carrying and control couples undergoing IVF/ICSI treatments.

STUDY DESIGN

Retrospective analysis of 72 Yqh+ carriers and 986 Yqh+ non-carriers undergoing their first cycle of ART in a single centre between August 2005 and May 2011.

RESULTS

Yqh+ carrying couples had significantly worse reproductive outcomes compared with control couples undergoing IVF treatment. There were a significantly higher cancellation rate (20.69% vs 7.9%; P<0.05; OR, 3.03; CI, 1.18-7.79) and a significant lower fertilisation rate (50.05% vs 66.01%; P<0.05; OR, 0.61; CI, 0.49-0.57), implantation rate (8.33% vs 20.87%; P<0.05; OR, 0.35; CI, 0.14-0.87), good quality embryo ratio (44.70% vs 57.89%; P<0.05; OR, 0.59; CI, 0.43-0.80) and clinical pregnancy rate (17.39% vs 39.59%; P<0.05; OR, 0.32; CI, 0.11-0.96) in Yqh+ group compared with control group undergoing IVF treatment. Yqh+ carrying couples had similar reproductive outcomes compared with control couples undergoing ICSI treatment.

CONCLUSIONS

The Y chromosome polymorphic variant Yqh+ most likely plays a role in infertility. Yqh+ couples with poor reproductive outcomes in IVF treatment can be advised to undergo ICSI to improve their reproductive results in the next cycle.

The role of male chromosomal polymorphism played in spermatogenesis and the outcome of IVF/ICSI-ET treatment

Chromosomal polymorphism has been reported to be associated with infertility, but its effect on IVF/ICSI-ET outcome is still controversial. To evaluate whether or not chromosomal polymorphism in men plays a role in spermatogenesis and the outcome of IVF/ICSI-ET, we retrospectively analysed 281 infertile couples. Measures included fertilization rate, implantation rate, pregnancy rate, clinical pregnancy rate, ongoing pregnancy rate, early miscarriage rate and preterm rate. Men with chromosomal polymorphism had significantly higher frequencies of severe oligozoospermia and azoospermia than those without (37.12% vs. 16.11%, p < 0.001; 27.27% vs. 10.74%, p < 0.001; respectively). Significantly, lower fertilization rate (68.02% vs. 78.00%, p < 0.001) and clinical pregnancy rate (45.00% vs. 66.67%, p = 0.031) were observed in polymorphism-carrying men with severe oligozoospermia compared with non-carriers with severe oligozoospermia. This suggests that chromosomal polymorphism has adverse effects on spermatogenesis, negatively influencing the outcome of IVF/ICSI-ET treatment. Polymorphic variations on the Y chromosome have been found to be the most prevalent polymorphism in infertile men, most frequently occurring in patients with severe oligozoospermia.

Chromosomal and molecular abnormalities in a group of Brazilian infertile men with severe oligozoospermia or non-obstructive azoospermia attending an infertility service

PURPOSE

To determine the frequency of genetic alterations in a population of Brazilian infertile men with severe oligozoospermia or non-obstructive azoospermia.

MATERIALS AND METHODS

Retrospective study of a group of 143 infertile men with severe oligozoospermia or non-obstructive azoospermia from the Andrology Outpatient Clinic of the Human Reproduction Service at the ABC School of Medicine. Of these patients, 100 had severe oligozoospermia, and 43 non-obstructive azoospermia. All patients underwent a genetic study which included karyotype analysis and Y-microdeletion investigation.

RESULTS

Genetic abnormalities were found in 18.8% of the studied patients. Chromosomal abnormalities were found in 6.2% of the patients, being more prevalent in the azoospermia group (11.6%) than in the oligozoospermia group (4%). Chromosomal variants were found in 8.3%, and Y-chromosome microdeletions in 4.2% of patients.

CONCLUSION

The high frequency of genetic alterations (18.8%) in our series justified performing a genetic investigation in a population with idiopathic infertility, as results may help determine the prognosis, as well as the choice of an assisted reproduction technique. Moreover, a genetic investigation could minimize the risk of transmitting genetic abnormalities to future generations such as genetic male infertility, mental retardation, genital ambiguity and/or birth defects.

DYZ1 copy number variation, Y chromosome polymorphism and early recurrent spontaneous abortion/early embryo growth arrest

OBJECTIVES

To find the association between recurrent spontaneous abortion (RSA)/early embryo growth arrest and Y chromosome polymorphism.

STUDY DESIGN

Peripheral blood samples of the male patients of big Y chromosome, small Y chromosome and other male patients whose partners suffered from unexplained RSA/early embryo growth arrest were collected. PCR and real-time fluorescent quantitative PCR were used to test the deletion and the copy number variation of DYZ1 region in Y chromosome of the patients. A total of 79 big Y chromosome patients (48 of whose partners suffered from RSA or early embryo growth arrest), 7 small Y chromosome patients, 106 other male patients whose partners had suffered from unexplained RSA or early embryo growth arrest, and 100 normal male controls were enrolled.

RESULTS

There was no fraction deletion of DYZ1 detected both in big Y patients and in normal men. Of RSA patients, 1 case showed deletion of 266bp from the gene locus 25-290bp, and 2 cases showed deletion of 773bp from 1347 to 2119bp. Of only 7 small Y chromosome patients, 2 cases showed deletion of 266bp from 25 to 290bp, and 4 cases showed deletion of 773bp from 1347 to 2119bp and 275bp from 3128 to 3420bp. The mean of DYZ1 copies was 3900 in normal control men; the mean in big Y patients was 5571, in RSA patients was 2655, and in small Y patients was 1059. All of the others were significantly different (P<0.01) compared with normal control men, which meant that DYZ1 copy number in normal control men was less than that of big Y chromosome patients, and was more than that of unexplained early RSA patients and small Y patients.

CONCLUSIONS

The integrity and copy number variation of DYZ1 are closely related to the Y chromosome length under microscope. The cause of RSA/early embryo growth arrest in some couples may be the increase (big Y patients) or decrease of DYZ1 copy number in the husbands' Y chromosome.

Do polymorphic variants of chromosomes affect the outcome of in vitro fertilization and embryo transfer treatment?

BACKGROUND

The aim of this study was to investigate the effect of chromosomal polymorphic variations on the outcome of IVF and embryo transfer (IVF–embryo transfer) treatment for infertile couples.

METHODS

During the period from October 2006 to December 2009, 1978 infertile couples who had received their first IVF–embryo transfer treatment cycle in our hospital were selected for this retrospective study, and the frequency of chromosomal polymorphic variations was calculated. From these, 1671 couples were selected and divided into three groups: 1402 couples with normal chromosomes (Group 1/control group), 82 couples with chromosomal polymorphic variations in only females (Group 2) and 187 couples with chromosomal polymorphic variations in only males (Group 3). The clinical pregnancy rates (CPR), early miscarriage rates and ongoing pregnancy rates after IVF–embryo transfer treatment were compared.

RESULTS

There were no statistically significant differences among the three groups in implantation rates (29.37% in the control group, 29.70% in Group 2 and 31.41% in Group 3, P > 0.05) and CPR (45.86, 46.34 and 51.87%, respectively, P > 0.05). Although there was a trend toward higher first trimester pregnancy loss rates in Group 3 (male chromosomal polymorphic variations), but not in Group 2, compared with normal karyotype couples (10.31 versus 6.84%), the difference did not reach significance (P > 0.05).

CONCLUSIONS

Chromosomal polymorphic variations appear to have no adverse effects on the outcome of IVF–embryo transfer treatment.