Frequency of Y chromosome microdeletions and chromosomal abnormalities in infertile Thai men with oligozoospermia and azoospermia

Effects of coadministration of DHA and vitamin E on spermatogram, seminal oxidative stress, and sperm phospholipids in asthenozoospermic men: a randomized controlled trial

BACKGROUND

It is unknown which compounds in spermatozoa or seminal plasma may be involved in the regulation of sperm motility.

OBJECTIVES

The aim of this study was to investigate the effects of DHA (22:6n-3), vitamin E, and their probable interactions in men with asthenozoospermia.

METHODS

A factorial, randomized, double-blind, placebo-controlled trial was conducted in infertility clinics in Tehran, Iran. The participants were idiopathic asthenozoospermic men aged 20-45 y, with normal endocrine function. Their concentration of spermatozoa and percentage of morphologically normal spermatozoa were equal to or above the lower reference limits, according to the fifth edition of the WHO guideline. Out of 717 men referred to the infertility clinics, 180 asthenozoospermic men were randomly assigned to 1 of 4 groups according to stratified blocked randomization by age and sperm concentration. Participants took daily 465 mg DHA plus 600 IU vitamin E (DE), 465 mg DHA plus placebo (DP), 600 IU vitamin E plus placebo (EP), or both placebo capsules (PP) for 12 wk. Sperm characteristics, oxidative stress of seminal plasma, serum and sperm membrane fatty acids, dietary intakes, anthropometric measurements, and physical activity were measured at baseline and after 12 wk.

RESULTS

After the intervention, mean ± SD sperm progressive motility was greater in the DE group (27.9 ± 2.8) than in the DP (25.7 ± 3.4), EP (26.1 ± 2.8), and PP (25.8 ± 2.6) groups (P < 0.05). Sperm count (P = 0.001) and concentration (P = 0.044) increased significantly in the DE group compared with the other 3 groups, whereas other semen parameters were not significantly different between the groups after the intervention. Serum concentrations of n-3 PUFAs were significantly higher in the DE and DP groups than in the EP and PP groups.

CONCLUSIONS

Combined DHA and vitamin E supplements led to increased sperm motility; however, no significant changes occurred in sperm morphology and vitality in asthenozoospermic men.This trial was registered at clinicaltrials.gov as NCT01846325.

Chromosomal abnormalities and Y chromosome microdeletions in infertile men with azoospermia and oligozoospermia in Eastern China

Objective

The objective was to investigate the frequency and type of chromosomal abnormalities and Y chromosome microdeletions in infertile men with azoospermia and oligozoospermia to ensure appropriate genetic counseling before assisted reproduction in Eastern China.

Methods

A total of 201 infertile men (148 with azoospermia and 53 with oligozoospermia) were enrolled. Real-time PCR using six Y-specific sequence-tagged sites of the azoospermia factor (AZF) region was performed to screen for microdeletions. Karyotype analyses were performed on peripheral blood lymphocytes with standard G-banding.

Results

Out of 201 infertile patients, 22 (10.95%) had Y microdeletions [17/148 (11.49%) men with azoospermia and 5/53 (9.43%) men with oligozoospermia]. The most frequent microdeletions were in the AZFc region, followed by the AZFa+b + c, AZFb+c, AZFa, and AZFb regions. Chromosomal abnormalities were detected in 18.91% (38/201) of patients, 34 of which were sex chromosome abnormalities (16.92%) and 4 of which were autosomal abnormalities (1.99%). Chromosomal abnormalities were more prevalent in men with azoospermia (22.97%) than in those with oligozoospermia (7.55%).

Conclusions

We detected a high incidence of chromosomal abnormalities and Y chromosomal microdeletions in infertile Chinese men with azoospermia and oligozoospermia. These findings suggest the need for genetic testing before the use of assisted reproduction techniques.

High frequency of microdeletion in TTY2 gene family in peripheral blood leukocytes of non-obstructive azoospermia patients

About 10-15% of non-obstructive azoospermia (NOA) patients show AZFc microdeletion in their blood leukocytes. However, if AZF genes were involved in impaired spermatogenesis, a higher frequency of chromosomal microdeletions was expected. In this study the frequency of AZFc microdeletion was compared with TTY2 gene family, i.e., TTY2A2A and TTY2A12A in blood leukocytes of NOA patients and normal fertile control. In the present study 30 normal fertile individuals with mean age of 35.0 ± 6.0 and 30 NOA patients with mean age of 34.0 ± 7.0 were screened for microdeletion of TTY2L2A and TTY2L12A at Yq11 and Yp11 respectively and sequence-tagged site (STS) markers for AZFc gene using multiplex PCR technique. At the first step karyotyping was done for all subjects using standard G-banding technique to identify patients with normal karyotype as well as non-affected normal controls for molecular analysis. Results showed no AZFc microdeletion in normal and NAO patients whereas one TTY2L2A microdeletion in normal control (3.3%) and 4 in NOA (13.3%) was observed (p < 0.05). However our data indicated that 6 of 30 NOA patients (20%) showed TTY2L12A microdeletion whereas there was no observed microdeletion in normal control (p < 0.01). Results indicate that the studied genes might be involved in impaired spermatogenesis more effective than the routinely screened AZF genes in infertile men. Therefore, screening these genes along with AZF genes might be valuable for infertile patients. The reason why these genes are deleted from Y chromosome is not known but might be associated with genomic instability induced by environmental physico-chemical genotoxic agents.

Mild androgen insensitivity syndrome (MAIS): the identification of c.1783C>T mutation in two unrelated infertile men

Two unrelated men complaining of primary male infertility presented to Orient Hospital in Damascus city. Physical examination showed moderate hypoandrogenic features. Both men were azoospermic. Hormone profiles revealed an elevation of follicle-stimulating hormone in one patient, but all the other hormones tested were within normal limits for both patients. Further genetic analyses, including karyotype and microdeletions in the AZF region of the Y chromosome, were normal in both patients. Mild androgen insensitivity syndrome was expected in the two patients. Sequencing analysis of the first exon in the androgen receptor (AR) gene have shown c.1783C>T mutation in the two patients with azoospermia. This paper sheds light on the need to screen for mutations in the AR gene, causing male infertility whenever mild hypoandrogenic features are present with unexplained male infertility.

High frequency of TTTY2-like gene-related deletions in patients with idiopathic oligozoospermia and azoospermia

Genes located on Y chromosome and expressed in testis are likely to be involved in spermatogenesis. TTTY2 is a Y-linked multicopy gene family of unknown function that includes TTTY2L2A and TTTY2L12A at Yq11 and Yp11 loci respectively. Using PCR amplification, we screened for TTTY2L2A- and TTTY2L12A-associated deletions, in 94 Greek men with fertility problems. Patients were divided into three groups as following: group A (n = 28) included men with idiopathic moderate oligozoospermia, group B (n = 34) with idiopathic severe oligozoospermia and azoospermia, and group C (n = 32) with oligo- and azoospermia of various known etiologies. No deletions were detected in group C patients and 50 fertile controls. However, two patients from group A had deletions in TTTY2L2A (7.1%) and six in TTTY2L12A (21.4%), whereas from group B, four patients had deletions in TTTY2L2A (11.8%) and 10 in TTTY2L12A (29.4%). In addition, five patients from both groups A and B (8%) appeared to have deletions in both studied TTTY2 genes, although these are located very far apart. These results indicate that the TTTY2 gene family may play a significant role in spermatogenesis and suggest a possible mechanism of nonhomologous recombinational events that may cause genomic instability and ultimately lead to male infertility.

Relevance of genetic investigation in male infertility

Genetic causes can be directly responsible for various clinical conditions of male infertility and spermatogenic impairment. With the increased use of assisted reproduction technologies our understanding of genetic basis of male infertility has large implications not only for understanding the causes of infertility but also in determining the prognosis and management of such couples. For these reasons, the genetic investigations represent today an essential and useful tool in the treatment of male infertility. Several evidences are available for the clinical practice regarding the diagnosis; however, there are less information relative to the treatment of the genetic causes of male infertility. Focus of this review is to discuss the main and more common genetic causes of male infertility to better direct the genetics investigation in the treatment of spermatogenic impairment.

Association of azoospermia factor region deletions in infertile male subjects among Malaysians

Azoospermia factor region (AZF) deletions (AZFa, AZFb, AZFc and AZFd) in the Y chromosome were analysed in male infertility subjects in various populations with conflicting results. This study comprised of 54 infertile males and 63 fertile controls, and the frequency of AZFa, AZFb, AZFc and AZFd deletions were determined using conventional polymerase chain reaction (PCR) as well as real-time PCR-high resolution melting analysis-based methods. The results of this study showed that, three of 54 cases (5.55%) had AZF (a, b and c) deletions (two had AZFc and one had AZFa deletions). Four cases were found to have AZFd deletions (7.4%) with two of them being associated with AZFc deletions (P = 0.028). The frequency of AZF (a, b and c) deletions in Malaysian infertile male subjects was found to be comparable with other populations. AZFd deletions were found to be significant (P < 0.05) in male infertility and it may be associated with other types of AZF deletions.

Analysis of Y chromosome microdeletion in 1738 infertile men from northeastern China

OBJECTIVE

To determine the frequencies and the characteristics of Y chromosome microdeletion in infertile men from northeastern China to perform appropriate therapeutic choices.

MATERIALS AND METHODS

The study included 1738 infertile men. Sperm concentration was measured according to standard methods and karyotype analysis was performed on peripheral blood lymphocytes with standard G-banding. Multiplex polymerase chain reaction amplification using 9 specific sequence-tagged sites were selected to detect Y chromosome microdeletions.

RESULTS

The data showed that the frequency of Y chromosome microdeletion was 8.57%. The most common microdeletion, among the azoospermia factor (AZF) regions, was detected in the AZFc region, followed by AZFb+c, AZFb, AZFa+b+c, AZFa, and AZFa+c. One-hundred seven patients with Y chromosome microdeletion developed azoospermia, 39 developed severe oligozoospermia (sperm concentration ≤5 × 10(6)/mL), and 3 developed moderate oligozoospermia (sperm concentration >5 × 10(6)/mL and ≤10 × 10(6)/mL). Karyotype analysis was available for 130 patients with Y chromosome microdeletion and abnormal karyotypes were found in 19 patients (14.6%). The most frequent abnormal karyotype was 46,X,Yqh-(n = 7).

CONCLUSION

In northeastern China, Y chromosome microdeletion diagnosis should be performed before the use of intracytoplasmic sperm injection in infertile men with sperm count ≤10 × 10(6)/mL, especially in men with azoospermia.

Azoospermia factor microdeletions: occurrence in infertile men with azoospermia and severe oligozoospermia from China

Azoospermia factor (AZF) microdeletions are the most frequent genetic cause of male infertility after Klinefelter's syndrome. Although some assisted reproductive techniques such as intracytoplasmic sperm injection (ICSI) have been successfully introduced to clinical treatment for infertile males, the AZF microdeletions might be transmitted from infertile fathers to their male offspring during these procedures. Thus, it is important to carefully evaluate AZF microdeletions in infertile males before assisted reproductive techniques are performed. In this article, we aimed to investigate the frequencies of AZF microdeletions in 137 infertile males with azoospermia and severe oligozoospermia from Jilin province of China and analyse the relationship between the levels of reproductive hormones and AZF microdeletions. Result analysis showed that AZF microdeletions were present in 8 (8.70%) azoospermic males and 3 (6.67%) severely oligozoospermic males. The most frequent microdeletions were detected in the AZFc region, followed by AZFb + c, AZFb and AZFa. And there was no significant correlation between the AZF microdeletion and the levels of reproductive hormones. These findings reinforce the necessity of AZF microdeletion testing among infertile males prior to employment of assisted reproduction techniques in Jilin province of China.

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.

First study of microdeletions in the Y chromosome of Algerian infertile men with idiopathic oligo- or azoospermia

The human Y chromosome is essential for human sex determination and spermatogenesis. The long arm contains the azoospermia factor (AZF) region. Microdeletions in this region are responsible for male infertility. The objective of this study was to determine the frequency of Y microdeletions in Algerian infertile males with azoospermia and oligoasthenoteratozoospermia syndrome (OATS) and to compare the prevalence of these abnormalities with other countries and regions worldwide. A sample of 80 Algerian infertile males with a low sperm count (1-20 × 10(6) sperms/ml) as well as 20 fertile male controls was screened for Y chromosome microdeletions. 49 men were azoospermic and 31 men had OATS. Genomic DNA was isolated from blood and polymerase chain reaction was carried out with a set of 6 AZFa, AZFb and AZFc STS markers to detect the microdeletions as recommended by the European Academy of Andrology. Among the 80 infertile men screened for microdeletion, 1 subject was found to have microdeletions in the AZFc (sY254 and sY255) region. The deletion was found in azoospermic subjects (1/49, 2%). The overall AZF deletion frequency was low (1/80, 1.3%). AZF microdeletions were observed neither in the OATS group nor in the control group. The frequency of AZF microdeletions in infertile men from Algeria was comparable to those reported in the literature. We suggest analyzing 6 STS in the first step to detect Y microdeletions in our population.

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.

Cytogenetic abnormalities and Y-chromosome microdeletions in infertile Syrian males

Infertility is an important health issue affecting numerous couples. Approximately 30-50% of the cases of male infertility is due to unknown reasons. The main genetic factors involved in male infertility are chromosomal abnormalities and Y chromosome microdeletions within the Yq11 region. The genes controlling spermatogenesis located in the Yq11 region are termed azoospermia factor genes (AZF). Klinefelter syndrome (KS) is the most common of the chromosomal anomalies in the infertile male. AZF microdeletions on the Y chromosome are the most frequent genetic cause of male infertility. Screening for microdeletions in the AZFa, b and c regions of the Y chromosome showed a marked variation among different studies. The present study aimed to investigate the prevalence of such deletions in Syrian men. A total of 162 infertile males (97 azoospermic, 49 oligospermic and 16 severely oligospermic) were screened for chromosomal abnormalities and Y chromosome microdeletions using 28 markers in the AZF region. Twenty (12.34%) patients had chromosomal rearrangements, 17 of them showed sex chromosome abnormalities (11 of 17 patients within the azoospermic group had a KS of 64.7%), 2 patients had apparently balanced autosomal rearrangements, while 1 patient had an inversion. Of the 162 infertile men, 46 patients (28.4%) had Y chromosome microdeletions within the AZF-regions. Most frequently hit were the AZFc (34.8%), followed by the AZFbc, AZFa, AZFac, AZFbc, AZFb, AZFd, AZFab, AZFad, AZFbd, AZFabc and the AZFbcd. Combined AZF deletions involving three regions with chromosomal abnormalities were observed in one case. The higher frequency of AZF deletions in our study was comparable with frequencies in other countries and regions of the world, possibly due to the elevated number of the sequence-tagged site (STS) markers used for this screening.

Cytogenetic abnormalities in 222 infertile men with azoospermia and oligospermia in Iran: Report and review

BACKGROUND:

Infertility affects approximately 10%-15% of couples in reproductive age. In half of the couples, causes are male-related, associated with impaired spermatogenesis. There is a complex correlation between genetics and infertility. Several factors affect on gametogenesis, from which factors that lead to chromosomal abnormalities are one of the best known. The aim of this study was to determine type and rate of chromosomal abnormalities in infertile azoospermic and oligospermic males in Iranian population.

MATERIALS AND METHODS:

The records of a total of 222 participants were evaluated retrospectively.

RESULTS:

As a whole we observed 13.96% chromosomal abnormality, from which 12.15% showed numerical and 1.8% showed structural abnormalities.

CONCLUSION:

Comparison of our results with the review of the literature shows a higher incidence (4- fold) of gonosomal, in particular, numerical gonosomal, chromosomal anomalies. Cytogenetic analysis is strongly suggested for infertile men, particularly in those who suffer from azoospermia.

Association of spermatogenic failure with the b2/b3 partial AZFc deletion

Infertility affects around 1 in 10 men and in most cases the cause is unknown. The Y chromosome plays an important role in spermatogenesis and specific deletions of this chromosome, the AZF deletions, are associated with spermatogenic failure. Recently partial AZF deletions have been described but their association with spermatogenic failure is unclear. Here we screened a total of 339 men with idiopathic spermatogenic failure, and 256 normozoospermic ancestry-matched men for chromosome microdeletions including AZFa, AZFb, AZFc, and the AZFc partial deletions (gr/gr, b1/b3 and b2/b3).

AZFa and AZFc deletions were identified in men with severe spermatogenic failure at similar frequencies to those reported elsewhere. Gr/gr deletions were identified in case and control populations at 5.83% and 6.25% respectively suggesting that these deletions are not associated with spermatogenic failure. However, b2/b3 deletions were detected only in men with spermatogenic failure and not in the normospermic individuals. Combined with our previous data this shows an association of the b2/b3 deletion (p = 0.0318) with spermatogenic failure in some populations. We recommend screening for this deletion in men with unexplained spermatogenic failure.

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.

Male infertility in Northeast China: a cytogenetic study of 135 patients with non-obstructive azoospermia and severe oligozoospermia

PURPOSES

To detect the frequency and types of chromosomal anomalies with non-obstructive azoospermia and severe oligozoospermia in Northeast China, and to compare the frequencies with other regions of China and the world. To investigate the general characteristics of this population.

METHODS

Eighty-one men with non-obstructive azoospermia and 54 men with severe oligozoospermia were recruited. Karyotype analyses were performed on peripheral blood lymphocytes using standard G-banding. Measurements of follicle-stimulating hormone, testosterone, prolactin, and inhibin B were obtained.

RESULTS

The frequency of chromosomal anomalies for patients with non-obstructive azoospermia (17.28%) was comparable with studies from Europe, Africa, Asia, and other regions of China. However, the frequency for patients with severe oligozoospermia (9.26%) was slightly higher than reported from other Asian countries. The infertile men were more likely than the fertile to smoke and consume alcohol, and to have significantly lower levels of inhibin B.

CONCLUSIONS

For infertile men in Northeast China, chromosome analysis is a necessary part of routine genetic testing, and the contributing effects of high smoking and alcohol consumption rates of this population should be discussed during genetic counseling.

Y chromosome microdeletions in sperm DNA of infertile patients from Tamil Nadu, south India

Context:

Y chromosome microdeletions in infertile men of Tamil Nadu, South India.

Aim:

The paper assesses the association of Y chromosome microdeletions among infertile patients using several STS markers from each AZF (AZoospermic Factor) region and also aspires to determine whether the blood DNA microdeletion picture matches the semen DNA Yq microdeletion map.

Materials and Methods:

A total of 287 men, including 147 infertile men and 140 normozoospermic fertile controls were included for the study.

Results:

Screening 72 semen samples with the STS markers specific to AZF (a,b,c) regions showed Y chromosome microdeletions in 19 (12.9%) individuals. No deletion was observed in all the three AZF regions by screening 45 blood and 30 paired samples. None of the control men showed deletion for the 28 STS markers, which were used for the primary screening of the deletion of AZF a,b,c regions.

Conclusion:

Germ cell DNA can be analyzed for Yq microdeletions rather than blood DNA.

Use of ethnicity-specific sequence tag site markers for Y chromosome microdeletion studies

INTRODUCTION

Microdeletions in the azoospermia factor region on the long arm of Y chromosome are associated with spermatogenic failure. There are many markers for the diagnosis of Y chromosome microdeletion analysis, but in routine practice only a limited set of markers can be tested.

OBJECTIVE

The objectives of this study were to determine the frequency of Y chromosome microdeletion in idiopathic cases of male infertility in India, to attempt genotype-phenotype correlation, and to evaluate whether markers to be tested for diagnosis of Y chromosome microdeletion should be ethnicity specific.

METHODS

Microdeletions in the Y chromosome were analyzed in 200 infertile males. The six sequence tag site (STS) markers prescribed by the European Academy of Andrology (EAA) were used initially. Patients in whom no deletions were detected by use of these markers were tested by markers selected from other studies from India.

RESULTS

The STS markers prescribed by EAA detected deletions in only 6 (3%) of 200 infertile males. However, markers selected from previous Indian studies showed deletions in an additional 15 (7.5%) of infertile males. Overall, Y chromosome microdeletions were observed in 21 (10.5%) of 200 patients. Of these, 13 were cases of azoospermia and 8 were cases of severe oligospermia.

CONCLUSION

The markers prescribed by EAA alone are not suitable for the diagnosis of Y chromosome microdeletions in infertile males. The protocol for identification of Y chromosome microdeletions in cases of nonobstructive azoospermia/severe oligospermia would have to include a different set of STS markers.

Testicular gene expression in cryptorchid boys at risk of azoospermia

Despite timely and successful surgery, 32% of patients with bilateral and 10% with unilateral cryptorchidism will develop azoospermia. Cryptorchid boys at risk of azoospermia display a typical testicular histology of impaired mini-puberty at the time of the orchidopexy. During mini-puberty increased gonadotropin and testosterone secretion stimulate transformation of gonocytes into Ad spermatogonia. In the azoospermia risk group this transformation is to a great extent impaired. This study aimed to analyze data on whole genome expression signatures of undescended testes at risk of developing azoospermia. Twenty-three testicular biopsies from 22 boys were analyzed (19 testes from 18 boys with cryptorchidism and 4 contralateral descended testes from patients with testicular agenesis). Expression profiling identified 483 genes not or under-expressed in the azoospermia risk group compared with the control and low risk for azoospermia (LAZR) groups. Annotated loci were associated with spermatogenesis. Other significant genes were cellular defense response genes and hormone-controlled loci involved in spermatogenesis. Some genes transcribed in normal adult meiotic and post-meiotic germ cells are activated in healthy juvenile Ad spermatogonia. Thus, molecular events initiating the testicular expression program at the onset of puberty and maintaining it during adulthood occur very early in prepubertal testes. This molecular event is to a great extent impaired in the high risk for azoospermia (HAZR) group lacking Ad spermatogonia (stem cells for spermatozoa) indicating impaired mini-puberty.

Cytogenetic abnormalities detected in patients with non-obstructive azoospermia and severe oligozoospermia

PURPOSE

To find the frequency and types of major chromosomal abnormalities with nonobstructive azoospermia and severe oligozoospermia to give appropriate genetic counseling before assisted reproduction techniques in Isparta (South of Turkey), and to investigate the general characteristics in this infertile male population.

METHODS AND PATIENTS

A total of 115 infertile males (92 were azoospermic, 23 severe oligospermic) were studied for the cytogenetic evaluation prior to use of assisted reproduction techniques. Also, 60 fertile males as a control group were studied. Karyotyping was performed on peripheral blood lymphocytes according to the standard methods. Levels of luteinising hormone, follicle-stimulating hormone (FSH), testosterone and prolactin were obtained and a testicular sonography examination was conducted.

RESULTS

The total prevalence of chromosomal abnormalities was found to be 4.3% (5/115), including 4 patients with Klinefelter's Syndrome and 1 patient with gonadal dysgenesis (46XX). All of them were azoospermic males, corresponding to a frequency of 5.4% (5/92 patients). Oligozoospermic males and control males had no chromosomal abnormalities. There was a significant difference in serum FSH, LH, mean testicular volume and smoking when comparing patients (both azoospermic and oligozoospermic) and control groups (p<0.05). Also, there was a significant difference in serum FSH, LH and mean testicular volume when compared with azoospermic and oligozoospermic patients (p<0.05).

CONCLUSIONS

The occurrence of chromosomal abnormalities among infertile males strongly suggests the need for routine genetic testing and counseling prior to the employment of assisted reproduction techniques.

Male infertility in China: laboratory finding for AZF microdeletions and chromosomal abnormalities in infertile men from Northeastern China

PURPOSES

To investigate the frequencies of AZF microdeletions and chromosomal abnormalities in infertile men from Northeastern China. Moreover, to compare the prevalence of these abnormalities with other countries and regions in the world.

METHODS

305 infertile men were enrolled. A complete semen analysis and reproductive hormones were measured according to standard methods. Multiplex polymerase chain reaction (PCR) amplification using nine specific sequence-tagged sites (STS) were used to detect AZF microdeletions. Karyotype analyses were performed on peripheral blood lymphocytes with standard G-banding.

RESULTS

Of the 305 infertile men, 28 (9.2%) had AZF microdeletions and 26 (8.5%) had chromosomal abnormalities. The most frequent microdeletions were in the AZFc+d, followed by AZFc, AZFb+c+d and AZFa. A total of 19 patients (82.6%) had Klinefelter's syndrome (47, XXY) in the azoospermic group.

CONCLUSIONS

The freqencies of AZF microdeletions and chromosomal abnormalities in infertile men from Northeastern China were comparable with infertile men from other countries and regions. However, there was a slightly higher prevalence rate of AZF microdeletions in oligozoospermic patients than reported in previous studies.

Cytogenetic and Y chromosome microdeletion screening studies in infertile males with Oligozoospermia and Azoospermia in Southeast Turkey

PURPOSE

In view of the genetic risks for the next generation, the importance of careful evaluation of karyotypes and AZF microdeletions in male infertility prior to assisted reproduction is evident. In the present study, it is aimed to investigate the frequency and types of both major chromosomal abnormalities by using standard cytogenetic methods and Y chromosome microdeletions of infertile males with azoospermia and oligozoospermia to give appropriate genetic counseling before assisted reproduction techniques in southeast Turkey.

METHODS

A total of 80 infertile males (52 were azoospermic, 25 oligospermic and 3 asthenospermic) were studied for the cytogenetic evaluation and molecular AZF screening program prior to use of assisted reproduction techniques. A detailed history was taken for each man. Karyotyping was performed on peripheral blood lymphocytes according to standard methods. Polymerase chain reaction (PCR) amplification by using 15 Y-specific sequence-tagged sites of AZF region was performed to screen the microdeletions in the AZF region of Y chromosome.

RESULTS

Of 80 cases, 71 had normal karyotype (46,XY). The total prevalence of chromosomal abnormalities was found to be 11.2% (9/80), including seven patients with Klinefelter syndromes and two patients with balanced autosomal rearrangements. All of the patients with Klinefelter Syndrome had azoospermia, but carriers with translocation had oligospermia. The deletions of Y chromosome were seen in one patient (1.3%) with features of normal karyotype and azoospermia. Microdeletions were seen in the AZFc and AZFd regions. Neither AZFa nor AZFb microdeletions were detected.

CONCLUSIONS

The occurrence of chromosomal anomalies and Y chromosome microdeletions among infertile males strongly suggests the need for routine genetic testing and counseling prior to employment of assisted reproduction techniques.

Clinical consequences of microdeletions of the Y chromosome: the extended Münster experience

A total of 3179 patients were screened for Y-chromosome microdeletions and 821 patients for partial AZFc deletions. Thirty-nine Y-chromosomal microdeletions were found (2.4% of men with <1 x 10(6)/ml spermatozoa): two AZFa, two AZFb, one AZFbc, one partial AZFb, one partial AZFb+c and 32 AZFc (b2/b4). Partial AZFc deletions were found in 45 patients (5.5%), mostly gr/gr deletions (n = 28). In patients with AZFc deletion, azoospermia was found in 53.1% and sperm concentrations of mostly <0.1 x 10(6)/ml were found in 46.9%. Semen analyses and FSH measurements showed no trend over time. Elongated spermatids were seen in 6/15 AZFc patients and bilateral Sertoli cell-only was found in 4/15. Testicular sperm extraction (TESE) was attempted in 10 patients and spermatozoa were found in six. Compared with infertile men matched by sperm concentration, no differences in hormonal and seminal parameters could be found in patients with AZFc or gr/gr deletions. It is concluded that: (i) frequency of AZF deletions in Germany is much lower than in other countries; (ii) AZFc deletions are associated with severe disturbances of spermatogenesis and TESE is not possible in half of these patients; (iii) AZFc and gr/ gr deletions are not associated with any clinical diagnostic parameter; (iv) and no trend is apparent over time.