CHROMOSOMAL ABNORMALITIES AND POLYMORPHISMS IN MEXICAN INFERTILE MEN

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).

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.

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 ABNORMALITIES IN PATIENTS WITH AZOOSPERMIA IN WESTERN MEXICO

In order to assess the frequency of chromosomal abnormalities in azoospermic males from western Mexico, we carried out a retrospective study in 227 patients. Forty-three (18.9%) cases with an abnormal karyotype were found. The most frequent chromosomal anomaly was 47,XXY, which was identified in 35 subjects (15.4%). In six cases (2.6%), structural aberrations were detected: two Robertsonian translocations [(45,XY,t(13;22)(p11;p11) and (45,XY,t(13;15)(p11;p11)], a Y;autosome translocation [46,XY,der(15)t(Y;15)(q12;p11)], and three mosaics [mos45,X/46,X,idic(Y)(q11)]. In general, these findings are in accordance with those from other surveys and confirm that the XXY aneuploidy is the most frequent chromosomal abnormality in azoospermic individuals.

Male infertility related to an aberrant karyotype, 46,XY,9ph,9qh+

OBJECTIVE

To report a man with primary infertility and variant karyotype.

DESIGN

Case report.

SETTING

Private practice.

PATIENT(S)

A 37-year-old man with 4 years of primary infertility due to oligoasthenozoospermia.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

G- and C-banding. Polymerase chain reaction for SRY, DBY, RBMY, DAZ, AMELX, and AMELY.

RESULT(S)

G-band analysis of the proband revealed a 46,XY,9ph,9qh+ karyotype. C-banding confirmed increase in the heterochromatin in one chromosome 9 and inversion in the other.

CONCLUSION(S)

The morphologic difference between the homologous chromosomes 9 may have been responsible for an error in crossing-over, leading to aberrant spermatozoa and consequently to infertility.

Chromosome heteromorphisms: an impact on infertility

INTRODUCTION

Cytogenetic heteromorphisms are described as heritable variations at specific chromosomal regions without a proven impact on phenotype.

MATERIALS AND METHODS

We compared the presence of chromosome heteromorphisms in the karyotypes of two patient groups. The first group of patients consisted of 276 individuals of 138 infertile couples. The second group, consisted of 1,130 amniocentesis samples. This group was considered to be a sample of the fertile population, as the fetus being karyotyped is the result of a spontaneous pregnancy. Fetal karyotyping was made due to the standard indications for prenatal diagnosis, such as abnormal maternal serum screening results.

RESULTS AND DISCUSSION

Eighteen infertile patients (6.52%) and twenty fetuses (1.77%) were found to have chromosome heteromorphisms. The difference between the two groups was statistically significant (p < 0.0001).

CONCLUSION

These results are consistent with other similar studies that suggest the yet undefined relationship between chromosome heteromorphisms and infertility.