A genetic survey of 1935 Turkish men with severe male factor infertility

An analysis of Y-chromosome microdeletion in infertile Korean men with severe oligozoospermia or azoospermia

PURPOSE

Infertility affects 10% to 15% of couples, and male factor accounts for 50% of the cases. The relevant male genetic factors, which account for at least 15% of male infertility, include Y-chromosome microdeletions. We investigated clinical data and patterns of Y-chromosome microdeletions in Korean infertile men.

MATERIALS AND METHODS

A total of 919 infertile men whose sperm concentration was ≤5 million/mL in two consecutive analyses were investigated for Y-chromosome microdeletion. Among them, 130 infertile men (14.1%) demonstrated Y-chromosome microdeletions. Medical records were retrospectively reviewed.

RESULTS

In 130 men with Y-chromosome microdeletions, 90 (69.2%) had azoospermia and 40 (30.8%) had severe oligozoospermia. The most frequent microdeletions were in the azoospermia factor (AZF) c region (77/130, 59.2%), followed by the AZFb+c (30/130, 23.1%), AZFa (8/130, 6.2%), AZFb (7/130, 5.4%), AZFa+b+c (7/130, 5.4%), and AZFa+c (1/130, 0.7%) regions. In men with oligozoospermia, 37 (92.5%) had AZFc microdeletion. Chromosomal abnormalities were detected in 30 patients (23.1%). Higher follicle-stimulating hormone level (23.2±13.5 IU/L vs. 15.1±9.0 IU/L, p<0.001), higher luteinizing hormone level (9.7±4.6 IU/L vs. 6.0±2.2 IU/L, p<0.001), and lower testis volume (10.6±4.8 mL vs. 13.3±3.8 mL, p<0.001) were observed in azoospermia patients compared to severe oligozoospermia patients.

CONCLUSIONS

Y-chromosome microdeletion is a common genetic cause of male infertility. Therefore, Y-chromosome microdeletion test is recommended for the accurate diagnosis of men with azoospermia or severe oligozoospermia. Appropriate genetic counseling is mandatory before the use of assisted reproduction technique in men with Y-chromosome microdeletion.

Prevalence of Y chromosome microdeletions among infertile Mongolian men

Y chromosome microdeletions are the second most common genetic cause of male infertility after Klinefelter syndrome. The aim of this study was to determine the patterns of Y chromosome microdeletions among infertile Mongolian men. A descriptive study was performed on 75 infertile men from February 2017 to December 2018. Y chromosome microdeletions were identified by polymerase chain reaction. Semen parameters, hormonal levels, and testis biopsy samples were examined. Among 75 infertile men, two cases of Y chromosome microdeletions were identified. The first case had an AZFa complete deletion and the other had an AZFc partial deletion. This study found that the proportion of Y chromosome microdeletions among infertile Mongolian men was 2.66%. The findings can be applied to in vitro fertilization and assisted reproductive technology, and our results will help clinicians improve treatment management for infertile Mongolian couples.

Chromosomal and Y-chromosome microdeletion analysis in 1,300 infertile males and the fertility outcome of patients with AZFc microdeletions

The present study investigated the frequency of chromosome aberrations and AZF microdeletions in infertile patients with nonobstructive azoospermia (NOA) or severe oligozoospermia. Additionally, the effect of the AZFc microdeletions on the success of microdissection testicular sperm extraction (microTESE) and intracytoplasmic sperm injection (ICSI) methods were evaluated. Peripheral blood samples were received from 1,300 infertile men with NOA and severe oligozoospermia. Karyotyping and FISH analysis were performed according to standard methods. AZF microdeletions were analysed using multiplex polymerase chain reaction or GML Y-chromosome Microdeletion Detection System consisting of 14 markers. The chromosomal aberrations and the AZF microdeletions frequency among 1,300 infertile men were 10.6% and 4.0% respectively. Either ejaculated spermatozoa or microTESE was performed on only in 19 out of 26 patients with AZFc deletions. Of the 19 patients, four had severe oligozoospermia and 15 had NOA. In eight out of 15 NOA patients, testicular mature spermatozoa were obtained (53.3%) and then ICSI was applied to mature oocytes. After undergoing ICSI treatment, clinical pregnancy and live birth outcome rates were found to be 37.5% and 25% respectively. These results suggest that infertile patients with AZFc microdeletion could achieve successful fertilisation pregnancies with the help of assisted reproductive technology.

Y-chromosome microdeletions in nonobstructive azoospermia and severe oligozoospermia

The aim of the present work was to present the outcomes of the patients with Y-chromosome microdeletions treated by intracytoplasmic sperm injection (ICSI), either using fresh (TESE) or frozen-thawed (TESE-C) testicular sperm and ejaculated sperm (EJAC). The originality of this work resides in the comparisons between the different types of Y-microdeletions (AZFa, AZFb, and AZFc) and treatments, with detailed demographic, stimulation, embryological, clinical, and newborn (NB) outcomes. Of 125 patients with Y-microdeletions, 33 patients presented severe oligozoospermia (18 performed ICSI with ejaculated sperm) and 92 secretory azoospermia (65 went for TESE with 40 having successful sperm retrieval and performed ICSI). There were 51 TESE treatment cycles and 43 TESE-C treatment cycles, with a birth of 19 NB (2 in AZFa/TESE-C, 12 in AZFc/TESE, and 5 in AZFc/TESE-C). Of the 29 EJAC cycles, there was a birth of 8 NB (in AZFc). In TESE and EJAC cycles, there were no significant differences in embryological and clinical parameters. In TESE-C cycles, there was a significant lower oocyte maturity rate, embryo cleavage rate and mean number of embryos transferred in AZFb, and a higher mean number of oocytes and lower fertilization rate in AZFc. In conclusion, although patients with AZFc microdeletions presented a high testicular sperm recovery rate and acceptable clinical outcomes, cases with AZFa and AZFb microdeletions presented a poor prognosis. Due to the reported heredity of microdeletions, patients should be informed about the infertile consequences on NB and the possibility of using preimplantation genetic diagnosis for female sex selection.

Correlation of genetic results with testicular histology, hormones and sperm retrieval in nonobstructive azoospermia patients with testis biopsy

To investigate the frequency and types of genetic results in different testicular histology of patients with nonobstructive azoospermia (NOA), and correlated with hormones and sperm retrieval (SR), a retrospective study was conducted in 286 Chinese NOA patients who underwent testis biopsy and 100 age-matched fertile men as the control group. Chromosome karyotype analyses were performed by the peripheral blood chromosome G-band detection method. Screening of Y chromosome microdeletions of azoospermia factor (AZF) region was performed by polymerase chain reaction (PCR) amplification of 11 sequence-tagged sites (STS). The serum levels of follicle-stimulating hormone, luteinising hormone and testosterone (T) and the appearance of scrotal ultrasound were also obtained. In 286 cases of NOA, 14.3% were found to have chromosomal alterations. The incidence of chromosomal abnormality was 2.8%. Sex chromosomal abnormalities were seen in six cases (four cases of Klinefelter's syndrome (47, XXY) and two cases of mosaics). The incidence of polymorphic chromosomal variants was 3% in the normal group and 11.5% in the NOA group. In total, 15.7% of NOA patients were found to have AZF microdeletions and AZF (c + d) was the most frequent one. The results of hormone and SR were found to be significantly different among all testicular histological types, whereas no significant differences were found when it comes to genetic alterations. It is concluded that the rate of cytogenetic alterations was high in NOA patients. So screening for chromosomal alterations and AZF microdeletions would add useful information for genetic counselling in NOA patients with testis biopsy and avoid vertical transmission of genetic defects by assisted reproductive technology.

The determination of possible genetic damage to women undergoing in vitro fertilization due to infertility caused by the male factor

In this study, we aimed at determining possible genetic damage to women who were exposed to in vitro fertilization (IVF) due to infertility with male factor. Four different genotoxicity tests were used in human lymphocytes in this study with regard to chromosomal aberration (CA), sister chromatid exchange (SCE), micronucleus (MN), and comet tests. There was a statistically significant increase in sister chromatid exchange (SCE) test in the study group compared with the control group. In addition, a higher rate of MN frequency was determined only in the 21–30 age range study group compared with the control group in the same age range. On the other hand, MN frequency did not differ significantly between the control and total study groups. In addition, there was no significant difference between the control group and the study group in terms of mitotic (MI), replication (RI), and nuclear division (NDI) indices. Furthermore, there was no statistically significant increase for chromosomal aberration and DNA damage to the study groups. Our results showed that in vitro fertilization treatments have a weak risk at the genetic level in cultured human lymphocytes.

High prevalence of genetic abnormalities in Middle Eastern patients with idiopathic non-obstructive azoospermia

INTRODUCTION

Our objective is to detect the frequency and types of major genetic abnormalities of idiopathic non-obstructive azoospermia (NOA) to give appropriate genetic counseling before assisted reproductive techniques (ART) in Middle East and to compare the frequencies with other regions of the world.

MATERIAL AND METHODS

A total of 880 Middle Eastern patients with NOA were recruited in this multicenter study for genetic evaluation prior to use of ART. Karyotyping was performed on peripheral blood lymphocytes according to standard G-banding methods, polymerase chain reaction (PCR) was performed to screen the microdeletions in the AZF region of the Y chromosome.

RESULTS

The present study shows that the total prevalence of genetic abnormalities is 28.41 %, including 184 patients (20.91 %) with chromosome disorder and 66 patients (7.5 %) with Y chromosome microdeletions. The most prevalent chromosome abnormality is Klinefelter's syndrome, which includes 161 patients (18.3 %), 7 patients had XX reversal male sex (0.8 %), 2 patients had 47XYY (0.23 %) and 2 patients had 45XO/46XY (0.23 %). Structural abnormalities occurred in 12 patients (1.36 %).

CONCLUSIONS

The high prevalence of genetic abnormalities (28.41 %) in our study strongly suggests the need for routine genetic testing and counseling prior to assisted reproduction in such population with idiopathic infertility, as a result may help determine the prognosis, as well as the choice of ART. Moreover it allows specific pre-implantation genetic testing to minimize the risk of transmitting genetic defects to offspring.

Chromosomal abnormalities in patients with oligozoospermia and non-obstructive azoospermia

PURPOSE

To assess the frequency and types of chromosomal abnormalities in 204 Ukrainian patients with non-obstructive azoospermia and oligozoospermia and 87 men with normozoospermia.

METHODS

Cytogenetic studies were performed on peripheral blood lymphocyte samples of 164 men with oligozoospermia, 40 men with non-obstructive azoospermia and 87 men with normozoospermia attending infertility clinic.

RESULTS

Chromosomal abnormalities were detected in 17% of patients with sperm disorders: in 35% of men with azoospermia and in 12.7% of men with oligozoospermia. The frequency of chromosomal abnormalities in patients with sperm disorders was significantly higher, than in patients with normozoospermia (P = 0.0001). An increase in the incidence of chromosomal abnormalities with the decrease of sperm count was observed. Chromosomal abnormalities were detected in 1.1% of patients with normozoospermia, 6.5% of patients with mild oligozoospermia (sperm count 5-15 × 10(6)/ml), 18.4% of patients with severe oligozoospermia (sperm count <5 × 10(6)/ml) and 35% of patients with azoospermia. A significant increase in the frequency of chromosomal abnormalities in patients with severe oligozoospermia was observed when compared to mild oligozoospermia (P = 0.01). A statistically significant association (P = 0.02) of chromosomal abnormalities and sex chromosome abnormalities (P = 0.0001) with azoospermia when compared to oligozoospermia was observed.

CONCLUSIONS

Our results highlight the importance of cytogenetic studies in patients with oligozoospermia (both mild and severe) and non-obstructive azoospermia. The presence of chromosomal abnormalities influences significantly the fertility treatment protocols, as well as provides a definite diagnosis to couples suffering from infertility.

Detection of Y Chromosome Microdeletion is Valuable in the Treatment of Patients With Nonobstructive Azoospermia and Oligoasthenoteratozoospermia: Sperm Retrieval Rate and Birth Rate

Purpose

We evaluated clinical characteristics, sperm retrieval rates, and birth rates in a relatively large number of infertile patients with Y chromosome microdeletions.

Materials and Methods

We retrospectively reviewed clinical data from 213 patients with nonobstructive azoospermia (NOA) and 76 patients with oligoasthenoteratozoospermia (OATS) who were tested for Y chromosome microdeletion from March 2004 to June 2011.

Results

Of the 289 patients, 110 patients presented with Y chromosome microdeletion and 179 patients presented with no microdeletion. Among the patients with Y chromosome microdeletions, 83/110 (75.4%) were NOA patients and 27/110 (24.5%) were OATS patients. After subdividing the patients with Y chromosome microdeletion, 29 had azoospermia factor (AZF)b-c microdeletion and 81 had AZFc microdeletion. The sperm retrieval rate was similar between patients with Y chromosome microdeletion and those with no microdeletion (26.6% vs. 25.6%, p=0.298) after multiple testicular sperm extraction (TESE). Excluding 53 patients who did not undergo TESE, 30 patients were analyzed. All of the 9 men with AZFb-c microdeletion had a complete absence of sperm despite multiple TESE. However, multiple TESE was successful for 9 of 21 patients with only AZFc microdeletion (p=0.041). Twenty patients with Y chromosome microdeletion gave birth.

Conclusions

In NOA and OATS patients, no significant difference in the sperm retrieval rate was shown between patients with Y chromosome microdeletion and those with no microdeletion. Patients with short Y chromosome microdeletion such as AZFc microdeletion have better prognoses for sperm retrieval and an increased chance of conception than do patients with larger microdeletions such as AZFb-c microdeletion.

Molecular and cytogenetic studies of 101 infertile men with microdeletions of Y chromosome in 1,306 infertile Korean men

OBJECTIVES

To determine the prevalence of Y chromosome microdeletions in infertile Korean men with abnormal sperm counts and to assess the clinical features and frequency of chromosomal abnormalities in Korean patients with microdeletions.

METHODS

A total of 1,306 infertile men were screened for Y chromosome microdeletions, and 101 of them had microdeletions. These 101 men were then retrospectively studied for cytogenetic evaluation, testicular biopsy and outcomes of IVF and ICSI.

RESULTS

The overall prevalence of Y chromosome microdeletions in infertile men was 7.7% (101/1,306). Most microdeletions were in the AZFc region (87.1%), including deletions of AZFbc (24.7%) and AZFabc (8.9%). All patients with AZFa, AZFbc and AZFabc deletions had azoospermia, whereas patients with an AZFc deletion usually had low levels of sperm in the ejaculate or in the testis tissues. Chromosomal studies were performed in 99 men with microdeletions, 36 (36.4%) of whom had chromosomal abnormalities. Among the infertile men with Y chromosome microdeletions in this study, the incidence of chromosomal abnormality was 48.6% in the azoospermic group and 3.7% in the oligozoospermic group. Among the 69 patients with microdeletions and available histological results, 100.0% of the azoospermic group and 85.7% of the oligozoospermic group had histological abnormalities. The frequency of both chromosomal abnormalities and histological abnormalities was higher in the azoospermic group compared to the oligozoospermic group. Thirty-four ICSI cycles with either testicular (n = 14) or ejaculated spermatozoa (n = 20) were performed in 23 couples with men with AZFc microdeletion. Thirteen clinical pregnancies (39.4%) were obtained, leading to the birth of 13 babies.

CONCLUSIONS

The study results revealed a close relationship between microdeletions and spermatogenesis, although IVF outcome was not significantly affected by the presence of the AZFc microdeletion. Nevertheless, Y chromosome microdeletions have the potential risk of being transmitted from infertile fathers to their offspring by ICSI. Therefore, before using ICSI in infertile patients with severe spermatogenic defects, careful evaluations of chromosomal abnormalities and Y chromosome microdeletions screening should be performed and genetic counseling should be provided before IVF-ET.

Clinical diagnostic testing for the cytogenetic and molecular causes of male infertility: the Mayo Clinic experience

PURPOSE

Approximately 8% of couples attempting to conceive are infertile and male infertility accounts for approximately 50% of infertility among couples. Up to 25% of males with non-obstructive infertility have chromosomal abnormalities and/or microdeletions of the long arm of the Y-chromosome. These are detected by conventional chromosome and Y-microdeletion analysis. In this study, we reviewed the results of testing performed in the Mayo Clinic Cytogenetics and Molecular Genetics Laboratories and compared our findings with previously published reports.

METHODS

This study includes 2,242 chromosome studies from males ≥18 years of age referred for infertility between 1989 and 2000 and 2,749 Y-deletion molecular studies performed between 2002 and 2009.

RESULTS

14.3% of infertile males tested by karyotyping had abnormalities identified. These include: (258) 47,XXY and variants consistent with Klinefelter syndrome, (3) combined 47,XXY and balanced autosomal rearrangements, (9) 47,XYY, (9) Y-deletions, (7) 46,XX males, (32) balanced rearrangements, and (1) unbalanced rearrangement. 3.6% of males tested for Y-microdeletion analysis had abnormalities identified, 90% of which included a deletion of the AZFc region.

CONCLUSIONS

This study highlights the need of males suffering from non-obstructive infertility to have laboratory genetic testing performed. An abnormal finding can have significant consequences to assisted reproductive techniques and fertility treatment, and provide a firm diagnosis to couples with longstanding infertility.

Oocyte activation, phospholipase C zeta and human infertility

BACKGROUND

Mammalian oocytes are activated by intracellular calcium (Ca(2+)) oscillations following gamete fusion. Recent evidence implicates a sperm-specific phospholipase C zeta, PLCζ, which is introduced into the oocyte following membrane fusion, as the responsible factor. This review summarizes the current understanding of human oocyte activation failure and describes recent discoveries linking certain cases of male infertility with defects in PLCζ expression and activity. How these latest findings may influence future diagnosis and treatment options are also discussed.

METHODS

Systematic literature searches were performed using PubMed, ISI-Web of Knowledge and The Cochrane Library. We also scrutinized material from the United Nations and World Health Organization databases (UNWHO) and the Human Fertilization and Embryology Authority (HFEA).

RESULTS AND CONCLUSIONS

Although ICSI results in average fertilization rates of 70%, complete or virtually complete fertilization failure still occurs in 1-5% of ICSI cycles. While oocyte activation failure can, in some cases, be overcome by artificial oocyte activators such as calcium ionophores, a more physiological oocyte activation agent might release Ca(2+) within the oocyte in a more efficient and controlled manner. As PLCζ is now widely considered to be the physiological agent responsible for activating mammalian oocytes, it represents both a novel diagnostic biomarker of oocyte activation capability and a possible mode of treatment for certain types of male infertility.

Preimplantation genetic diagnosis (PGD) for extremes--successful birth after PGD for a consanguineous couple carrying an identical balanced reciprocal translocation

OBJECTIVE

To report a healthy birth after preimplantation genetic diagnosis (PGD) performed for a consanguineous couple carrying an identical familial reciprocal translocation in both partners.

DESIGN

Case report.

SETTING

In vitro fertilization (IVF) clinic and genetic laboratory in a private hospital.

PATIENT(S)

Consanguineous couple carrying the same balanced reciprocal translocation: 46,XX,t(1;16)(q12;q11.2) and 46,XY,t(1;16)(q12;q11.2).

INTERVENTION(S)

25 oocyte-cumulus complexes were retrieved 36 hours after human chorionic gonadotropin injection; metaphase II oocytes were fertilized by intracytoplasmic sperm injection; single blastomere biopsy was performed on 15 embryos on day 3; one embryo was found to be normal or balanced according to fluorescent in situ hybridization studies, embryo transfer was performed on day 4.

MAIN OUTCOME MEASURE(S)

Healthy birth of homozygous double translocation carrier twins with 46,XY,t(1;16)(q12;q11.2)mat,t(1;16)(q12;q11.2)pat karyotype.

RESULT(S)

Healthy monozygotic male twins were born at 36 weeks of gestation. Karyotype studies of the babies revealed that they are double translocation homozygotes: 46,XY,t(1;16)(q12;q11.2)mat,t(1;16)(q12;q11.2)pat. They are healthy and more than 4 years old later show no physical or mental abnormalities.

CONCLUSION(S)

To our knowledge, this is the first PGD study performed for a couple who carry the same reciprocal translocation. The twins born after this study are rare examples in the literature of healthy balanced reciprocal translocation homozygotes.