P-549 Paraclinical and spermogram evaluation of infertile males with balanced chromosomal rearrangements referred to Royan institute from 2009-2021

Study question

Whether balanced chromosomal rearrangements are associated with altered semen parameters/increased DNA Fragmentation Index (DFI), are the common breakpoints related to male infertility in patients ?

Summary answer

Balanced chromosomal rearrangements is associated with abnormal semen parameters and increased DFI in carriers. Chromosomes 9,1,3 showed the highest incidence of chromosomal rearrangement

What is known already

Among many factors, balanced chromosomal rearrangements are thought to be one of the major genetic factors influencing male infertility which can cause disorders related to spermogram, DNA fragmentation, increased risk of miscarriage and ART failure. Finding common chromosomal breakpoints in infertile men carrying balanced chromosomal translocations is significant since these patients usually possess normal clinical features. Numerous studies have been performed on the various chromosome translocations. However, there has not been any report on the common breakpoints in balanced chromosomal abnormalities related to male infertility in Iran.

Study design, size, duration

This cross-sectional study performed on 25000 patients’ files admitted to the Royan institute during the period 2009- 2021.Infertile men carrying balanced chromosomal rearrangements were included as case group. Sperm parameters, DFI and common chromosomal break points were evaluated

Participants/materials, setting, methods

25000 files of patients were reviewed. 252 infertile men carrying balanced chromosomal rearrangements and 252 men with normal karyotype were included (case and control group, respectively). Sperm concentration, motility (CASA), sperm morphology (Papanicolaou Staining),DFI (SCSA) and cytogenetic analysis of peripheral blood lymphocytes (G-banding) were evaluated. Numerical chromosomal abnormalities, deletions, marker chromosomes, alcohol or drug addiction, smoking, chemotherapy and radiation, varicocele and exposure to environmental pollution were excluded. The common chromosomal breakpoints in translocations were investigated.

Main results and the role of chance

Sperm concentration, total motility and normal morphology were significantly lower in balanced chromosomal rearrangements carriers compared to control group(p < 0.05). DFI in patient was significantly higher in comparison to control group(p < 0.05). Among different kind of chromosomal rearrangement carriers’, sperm concentration and total motility were lower in Robertsonian translocation carriers comparing to the Reciprocal translocation and inversion ones. The reciprocal translocation and inversion carriers did not differ regarding to sperm concentration and total motility. Meanwhile, normal morphology was lower in the translocation compared to inversion carriers. No difference was observed in DFI among carriers of balanced chromosomal rearrangements. Among case group, inversion accounted for the largest share, followed by Reciprocal, Robertsonian translocation and insertion. Group C had the highest frequency in reciprocal translocation, inversion and insertion among the chromosomal groups. The highest balanced translocation prevalence was related to three chromosomes 9,3, and1. 9q12,1p36,3p11 were the most frequent breakpoints among them. Chromosome 9 had the largest contribution to inversions,22 to reciprocal translocations and14 to Robertsonian translocations. In the Robertsonian translocation, group D showed the highest frequency. Interestingly, patients carrying normal variations such as pericentric inversion of chromosome 9showed a significant alteration in sperm parameters, therefore normal variations showed a possible relationship to infertility.

Limitations, reasons for caution

In order to achieve stronger statistical results on DFI, a larger sample size would be more helpful.

Wider implications of the findings

The results may be useful to identify the most common breakpoints and consequently genes related to male infertility and can suggest appropriate molecular mechanism for their infertility.

Trial registration number

not applicable

Clinical aspects of 49 infertile males with 45,X/46,XY mosaicism karyotype: A case series

Disorders of sex development (DSD) are congenital abnormalities as an atypical development process in either gonadal or chromosomal structure. It is the cause of the abnormality in phenotype and characteristics. Chromosomal analysis plays an important role in the DSD determination. 45,X/46,XY mosaicism is a rare karyotype, and its prevalence is about 1.5 in 10,000 newborns. It affects the growth, hormonal balance, gonad development and histology. All data such as height, male general appearance, testis size and volume, external genitalia, spermogram and hormonal levels, testis pathology, Y chromosome microdeletion and karyotype, and assisted reproductive technology (ART) outcome were recorded based on patients profile and history. We investigated 64 infertile males with 45,X/46,XY mosaicism. Fifteen cases who had structural abnormalities in Y chromosome were excluded. From 49 available spermogram, 21 cases reported as azoospermic men, while 28 of them classified as nonazoospermic patients in which four of them displayed normal spermogram. According to hormonal evaluation, there were no significant differences between azoospermic and nonazoospermic groups. In azoospermia, only three couples underwent an ART cycle in which all of them failed. From 14 nonazoospermic cases who entered into the ART cycle, three cases experienced a successful pregnancy that one of the prosperous outcomes was twins. In 45,X/46,XY cases, both 45,X and 46,XY cell lines are seen. Various distributions of both cell lines can reflect a wide range of phenotypes that may be the most comprehensive evaluation in infertile males with 45,X/46,XY karyotype. It assumes that karyotyping as a main diagnostic test can enable us to find these rare cases.

The impact of Chlamydia trachomatis infection on sperm parameters and male fertility: A comprehensive study

Chlamydia trachomatis (CT), an obligate intracellular bacterium, requires living cells to replicate. Half of men infected with CT are asymptomatic. CT infection can persist for up to four years within couples and affect their fertility. Chlamydia infection in men acts as a reservoir for transmission to women and can cause urinary tract inflammation, sperm DNA damage, and acute epididymitis. Semen samples from 1080 subfertile patients with normal and abnormal spermograms were examined to detect the presence of CT. An ELISA test was used to detect the presence of anti-CT IgA in these patients' seminal plasma. CT infection was also confirmed by molecular investigation using specific primers. In order to evaluate the effect of CT infections on the DNA Fragmentation Index (DFI), 40 CT-infected cases and 20 CT-negative controls were analyzed by a Sperm Chromatin Structure Assay using flow cytometry. Among 1080 patients with poor sperm parameters, 155 (14.3%) patients were diagnosed with CT, 11% among those with semen abnormalities and 26% among those without semen abnormalities patients. The DFI was statistically higher in cases than in controls (p < 0.05). Given the prevalence of infection and also the high frequency of asymptomatic CT infection among infertile individuals with poor sperm parameters, screening for infection in these patients is essential in order to avoid adverse sequelae. We propose that the higher rate of DFI in CT-infected infertile men might be an underlying cause of their infertility and this warrants greater attention.

46,XX males: a case series based on clinical and genetics evaluation

46,XX male sex reversal syndrome is one of the rarest sex chromosomal aberrations. The presence of SRY gene on one of the X chromosomes is the most frequent cause of this syndrome. Based on Y chromosome profile, there are SRY-positive and SRY-negative forms. The purpose of our study was to report first case series of Iranian patients and describe the different clinical appearances based on their genetic component. From the 8,114 azoospermic and severe oligozoospermic patients referred to Royan institute, we diagnosed 57 cases as sex reversal patients. Based on the endocrinological history, we performed karyotyping, SRY and AZF microdeletion screening. Patients had a female karyotype. According to available hormonal reports of 37 patients, 16 cases had low levels of testosterone (43.2%). On the other hand, 15 males were SRY positive (90.2%), while they lacked the spermatogenic factors encoding genes on Yq. Commencing the testicular differentiation in males, the SRY gene is considered to be very important in this process. Due to homogeneous results of karyotyping and AZF deletion, there are both positive and negative SRY cases that show similar sex reversal phenotypes. Evidences show that there could be diverse phenotypic differences that could be raised from various reasons.

Ubiquitin-specific protease (USP26) gene alterations associated with male infertility and recurrent pregnancy loss (RPL) in Iranian infertile patients

BACKGROUND AND PURPOSE

The human X chromosome is enriched with testis-specific genes that may be crucial for male fertility. Mutations in USP26 gene have been proposed to be associated with male infertility. Moreover, the importance of the ubiquitin pathway during different stages of mammalian fertilization and even embryo development has been addressed. Some mutations and haplotypes on this gene have been proposed to be associated with male infertility. In this study, five different mutations on USP26 were investigated: 1737 G > A, 1090 C > T, 370-371ins ACA, 494 T > C and 1423 C > T.

METHODS

The study included 166 infertile men with non-obstructive azoospermia, 72 male partners of couples who had previously experienced ≥3 clinical first trimester spontaneous abortions and 60 fertile men. Besides family history of reproduction, hormonal evaluation and semen analysis were performed. DNA was extracted from blood samples. PCR-SSCP, PCR-RFLP and PCR Product Cloning methods were used and resumed by sequencing to insure about the mutations. Moreover, USP26 gene expression was studied by Real-Time PCR after RNA extraction followed by cDNA synthesis from 24 testis biopsies in obstructive and non-obstructive azoospermia patients.

RESULTS

The results indicate that there is a haplotype between three observed mutations in Iranian population include: 370-371insACA, 1423C > T and 494 T > C. This haplotype was seen in control group as well. Surprisingly, total frequency of mutations in men with history of idiopathic RPL and azoospermic cases were significantly higher than that of in control groups (p < 0.05). Serum testosterone concentrations and testicular volume did not differ in the mutation positive group compared with the non-mutation group. About the USP26 gene expression, there is a significant difference between the expression levels of obstructive azoospermia, complete maturation arrest samples and SCO samples (P < 0.05).

CONCLUSIONS

According to our results, the USP26 gene may play an important role in male reproduction. The alterations of this gene may be involved in male infertility and RPL in Iranian population and may negatively affect testicular function.

Cytogenetic analysis of sperm nucleous components of iranian normal and sub-fertile individuals using zona free hamster oocytes

PURPOSE

The purpose of this study was to investigate whether infertility is affected by sperm chromatin and cytogenetic abnormalities. To this purpose, the frequency of sperm premature chromosome condensation (PCC) induction and numerical chromosome abnormalities in the sperm of normal and sub-fertile men were analyzed. PCC rate was studied for evaluating the role of sperm chromatin abnormalities in the process of nuclear decondensation.

DESIGN

Controlled prospective study.

SETTING

Infertility Genetics Department, Royan Institute.

PATIENT

Sub-fertile males who were referred for infertility treatment and sperm cytogenetical studies.

METHODS

Hamster oocytes were retrieved after super ovulation by PMSG and HCG injection. Following treatment with Hyaloronidase, zona was removed by trypsin digestion. Sperms were classified according to the morphology, movement and counts and then processed by swim up method. After capacitation, zona-free oocytes were incubated with sperms, and then transferred to fresh media containing colcemid. Slides were prepared using Tarkowskie's standard air-drying technique. Oocytes were analyzed using x 1000 microscope after staining in 5% of Giemsa.

MAIN OUTCOME MEASURE

The incidence of sperm aneuploidy, PCC and penetration rate in three groups were determined.

RESULTS

Regarding the PCC rate, a significantly higher frequency was found in infertile patients. (P < 0.001). The frequency of PCC in oligosperm samples was 36% compared to 19.37% in normal group. A higher frequency of numerical chromosome abnormalities was found in infertile patients. The rate of these abnormalities was 5.6% in normal group and 18.5% in oligospermic samples. Despite the considerable difference between those frequencies, this difference is not significant. (P > 0.05).

CONCLUSIONS

From the results it can be concluded that, formation of sperm PCC is a major cause of failed fertilization in individuals with sperm abnormalities. PCC may form due to chromatin abnormalities, improper DNA packing, chromosomal abnormalities and penetration delay of sperm. Also this may be involved in the etiology of some cases of idiopathic infertility. About numerical chromosome abnormalities although the differences are not significant, there is an association between sperm numerical chromosome abnormalities and male infertility. These abnormalities can be originated from meiotic process in spermatogenesis.