INCIDENCE OF MICRODELETIONS IN THE AZF REGION OF THE Y CHROMOSOME IN SLOVAK PATIENTS WITH AZOOSPERMIA

Concomitance of 47,XXY, a balanced reciprocal translocation of t(4;17)(q12;q11.2) encompassing SPINK2 at 4q12 and NOS at 17q11.2 and an AZFa sY86 deletion in an infertile male

OBJECTIVE

We present an infertile male who was incidentally detected to have Klinefelter syndrome, a balanced reciprocal translocation of t(4; 17) (q12; q11.2) and an AZFa sY86 deletion. We review the literature and discuss the significance of 47,XXY, t(4; 17) (q12; q11.2) and AZFa sY86 deletion in this case.

CASE REPORT

A 37-year-old married infertile male was referred for genetic studies of azoospermia. His height was 195 cm and his weight was 85 kg. He had been married for more than one year without any pregnancy in his wife. He was referred for genetic counseling. Cytogenetic analysis revealed a karyotype of 47,XXY,t(4; 17) (q12; q11.2). In addition to Klinefelter syndrome, a balanced reciprocal translocation and an AZFa microdeletion were found. Sequence analysis of SPINK2 and NOS was also performed. These two fertile related genes were located at the breakpoints of translocation respectively. Heterozygosity of single-nucleotide polymorphisms (SNPs) evidenced the presence of two alleles as well as no deletions occurred at the breakpoint regions. An AZF gene analysis revealed a microdeletion at the region of AZFa sY86 region.

CONCLUSION

Genetic analysis of an infertile male may detect multiple factors associated with azoospermia such as translocation, an AZF deletion and Klinefelter syndrome. This case emphasized the importance of tests for chromosomes and AZF deletions among patients with azoospermia. Complete genetic counseling of the consequence of a familial inheritance is also necessary to detect more family carrier members for the prevention of unbalanced chromosome in the offspring.

Bridging the Gap between AZF Microdeletions and Karyotype: Twelve Years' Experience of an Infertility Center

PURPOSE

Despite all past efforts, the current guidelines are not explicit enough regarding the indications for performing azoospermia factor (AZF) screening and karyotype, burdening clinicians with the decision to assess whether such tests are meaningful for the infertile male patient. These assessments can be costly and it is up to the healthcare practitioner to decide which are necessary and to weigh the benefits against economic/psychological harm. The aim of this study is to address such gaps and provide update on current management options for this group of patients.

MATERIALS AND METHODS

To address such gaps in male infertility management and to elucidate whether AZF screening is indicated in individuals who concomitantly harbor chromosomal abnormalities we conducted a retrospective cohort analysis of 10,388 consecutive patients with non-obstructive azoospermia (NOA) and severe oligozoospermia.

RESULTS

Previously, it has been suggested that all NOA cases with chromosomal defects, except males with 46,XY/45,X karyotype, have no indication for AZF screening. Our findings revealed that cases carrying the following chromosomal abnormalities inv(Y)(p11.2q12); idic(Y)(q11.2); 46,XY,r(Y); idic(Y)(p11.2) and der(Y;Autosome) (76/169; 44.9%; 95% CI, 37.7-52.5) should also be referred for AZF deletion screening. Here, we also report the correlation between sperm count and AZF deletions as a secondary outcome. In accordance with previously reported data from North America and Europe, our data revealed that only 1% of cases with >1×10⁶ sperm/mL had Y chromosome microdeletions (YCMs).

CONCLUSIONS

In the era of assisted reproduction, finding cost-minimization strategies in infertility clinics without affecting the quality of diagnosis is becoming one of the top prioritized topics for future research. From a diagnostic viewpoint, the results reflect a need to reconsider the different karyotype presentations and the sperm count thresholds in male infertility guidelines as indicators for YCM screening during an infertility evaluation.

Incidence of Y chromosome microdeletions in patients with Klinefelter syndrome

PURPOSE

The aim of this study was to study the incidence of Y chromosome microdeletions in a Caucasian population of Klinefelter syndrome (KS) patients and to investigate the possible association between Y chromosome microdeletions and KS.

MATERIALS AND METHODS

We conducted a retrospective study on 118 KS patients, 429 patients with non-obstructive azoospermia (NOA), and 155 normozoospermic men. Eight of the 118 KS patients had undergone testicular sperm extraction (TESE). All patients underwent semen examination and Y chromosome microdeletions evaluated by PCR, using specific sequence tagged site (STS) primer sets, which spanned the azoospermia factor AZFa, AZFb, and AZFc regions of the Y chromosome.

RESULTS

Semen analysis of the KS group revealed: 1 patient with oligozoospermia, 1 with severe oligoasthenoteratozoospermia, 2 with cryptozoospermia, and 114 with azoospermia. Eight of the 114 azoospermic KS patients underwent TESE, and spermatozoa were recovered from three of these, all of whom had non-mosaic karyotype 47, XXY. 10.7% of the NOA patients presented AZF microdeletions. In 429 cases with NOA, 8 cases had AZFa + b + c deletion, 6 cases had AZF b + c deletion, 4 cases had AZFa microdeletion, 8 cases had AZFb microdeletion, and 20 cases had AZFc microdeletion. Just one KS patient (0.8%) presented microdeletion in the AZFc region.

CONCLUSION

The percentage of microdeletions in KS patients was lower than in NOA patients, suggesting that AZF microdeletions and KS do not have a causal relationship and that Y chromosome microdeletions are not a genetic factor linked to KS.

Multiplex-Polymerase Chain Reaction for Detecting Microdeletions in The Azoospermia Factor Region of Y Chromosome in Iranian Couples with Non-Obstructive Infertility and Recurrent Pregnancy Loss

Background

Approximately 15% of couples are infertile with the male factor explaining approximately 50% of the cases. One of the main genetic factors playing a role in male infertility is Y chromosomal microdeletions within the proximal long arm of the Y chromosome (Yq11), named the azoospermia factor (AZF) region. Recent studies have shown there is a potential connection between deletions of the AZF region and recurrent pregnancy loss (RPL). The aim of this study is to examine this association by characterizing AZF microdeletions in two infertile groups: in men with non-obstructive infertility and in men with wives displaying RPL.

Materials and Methods

In this is a case-control study, genomic DNA was extracted from 80 male samples including 40 non-obstructive infertile men, 20 males from couples with RPL and 20 fertile males as controls. Multiplex polymerase chain reaction was used to amplify 19 sequence tagged sites (STS) to detect AZF microdeletions. Differences between the case and control groups were evaluated by two-tailed unpaired t test. P<0.05 were considered statistically significant.

Results

Only one subject was detected to have Y chromosome microdeletions in SY254, SY157 and SY255 among the 40 men with non-obstructive infertility. No microdeletion was detected in the males with wives displaying RPL and in 20 control males. Y chromosome microdeletion was neither significantly associated with non-obstructive infertility (P=0.48) nor with recurrent pregnancy loss.

Conclusion

Performing Testing for Y chromosome microdeletions in men with non-obstructive infertility and couples with RPL remains inconclusive in this study.

Gene Scanning for Microdeletions in the Azoospermia Factor Region of Y-Chromosome in Infertile Men of Gujarat, India

INTRODUCTION

Azoospermia Factor (AZF) microdeletions in Yq chromosome is one of the most frequent genetic cause associated with failure of spermatogenesis in males with infertility.

AIM

To figure out the Yq chromosome microdeletions frequency in infertile men from Gujarat region of India.

MATERIALS AND METHODS

In this study, 141 infertile men with azoospermia (n=41) and oligozoospermia (n=100) were examined along with 159 normozoospermic men. Eleven different markers spanning the azoospermia factor region of human Yq chromosome, amplified by sequence-tagged site Polymerase Chain Reaction (PCR) to detect the microdeletions. Sperm morphological analysis was done using papanicolau staining method.

RESULTS

Thirty four infertile men out of 141 presented Yq chromosome microdeletions. The frequency of AZF microdeletions was 31.71% in azoospermia and 21% in oligozoospermia patients. Only two oligozoospermia patients showed morphological defects.

CONCLUSION

Due to the presence of high frequency of Yq chromosome microdeletions in Gujarati infertile men, it is imperative to implement the AZF microdeletion screening in such patients as it results in male spermatogenesis dysfunctioning.

AZFa Microdeletions: Occurrence in Chinese Infertile Men and Novel Deletions Revealed by Semiconductor Sequencing

OBJECTIVE

To evaluate the frequency of azoospermia factor (AZFa) microdeletions among infertile men and establish a new high-throughput sequencing method to detect novel deletion types.

MATERIALS AND METHODS

A total of 3731 infertile men were included. Karyotype analysis was performed using G-band staining of peripheral blood lymphocytes. Polymerase chain reaction (PCR) amplification using specific sequence-tagged sites (STS) was performed to screen for AZF region microdeletions of the Y chromosome. A novel semiconductor sequencing method was established to detect high-resolution AZFa microdeletions.

RESULTS

Of 3731 infertile men, 341 (9.14%) had microdeletions in AZFa, AZFb, or AZFc. Thirteen of these (3.81%) had a deletion in the AZFa region (mean age: 27.3 ± 4 years, range: 22-34), which included 12 subjects with a normal karyotype (46, XY) and 1 with Klinefelter syndrome (47, XXY). Four of 10 subjects with complete AZFa microdeletions (sY86 and sY84 loss) underwent semiconductor sequencing. They all had DNA sequence deletions from nt 14469266 to 15195932, whereas their fathers had no deletions. One subject with partial AZFa microdeletion (sY86 loss) and his father underwent semiconductor sequencing and STS-PCR analysis. The same deletion (sY86 loss with DNA sequence deletion from nt 14469266 to 14607672) was identified in both subjects. Forty sperm donators and 50 infertile men showed no AZFa microdeletions by either method.

CONCLUSION

AZFa deletions are present at a low frequency in men with azoospermia or oligozoospermia. Novel sequencing methods can be used for these patients to reveal high-resolution AZFa microdeletions.

Clinical characteristics and treatment of azoospermia and severe oligospermia patients with Y-chromosome microdeletions

Clinical characteristics, testicular pathology, serum levels of reproductive hormones, and genetic analysis were compared among 100 azoospermic, 20 oligozoospermic cases with azoospermia factor (AZF) microdeletion, and 50 fertile males to evaluate the relationship between the AZF microdeletion regions and the azoospermia phenotype. AZF microdeletion region, testicular volume, and serum reproductive hormone levels of patients were compared against histological examination of testicular biopsies. The number of cases of AZFa, AZFb, AZFc, AZFb + c, and AZFa + b + c microdeletion was respectively 2 (1.7%), 15 (12.5%), 77 (64.2%), 24 (20.0%), and 2 (1.7%). The testicular volume of patient with AZF microdeletion was smaller (P < 0.01), while luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels were significantly higher than that of fertile individuals (P < 0.01 and P < 0.05, respectively). Among the patients, testicular volume with AZFb-microdeletion cases was larger compared to patients with AZFc or AZFb + c microdeletions (P < 0.05 and P < 0.01, respectively), whereas FSH levels were significantly lower than that of AZFc or AZFb + c microdeletions (P < 0.05). The Johnsen score of patients with an AZFb + c microdeletion was lower than that of patients with AZFb and AZFc microdeletions, but no significant difference was observed. Pathological findings of testicular biopsies poorly correlated with the pattern of AZF deletion, with the AZFc microdeletion exhibiting the most varied phenotypes. In subsequent assisted reproductive treatments, sperm from patients with an AZFc microdeletion that was obtained by testicular sperm aspiration (TESA) or microdissection testicular sperm extraction (m-TESE) were more likely to result in pregnancy. Combined with testis pathology pattern, the specific region of AZF microdeletion and hormonal assessments provide reliable prognostic information on the chance of successful sperm retrieval for assisted reproductive technologies.

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.

A new molecular diagnostic approach to assess Y chromosome microdeletions in infertile men

OBJECTIVE

A key cause of spermatogenetic failure in infertile males is microdeletions in the azoospermia factor (AZF) regions of the Y chromosome. This study screened for microdeletions in the AZF regions using suspension array technology and compared the results with those from polymerase chain reaction (PCR).

METHODS

Patients with spermatogenetic failure (n=507) and healthy control sperm donors (n=100) were recruited. DNA samples were analysed using both multiplex PCR with gel electrophoresis and suspension array technology.

RESULTS

The suspension array method identified 45 infertile males with Y chromosome microdeletions, while none was found in the controls. Amongst the AZF subregions, two cases had deletions in AZFa, three in AZFb, 35 in AZFc, three in AZFbc and two in AZFabc. The results from 507 patients were identical when analysed with either suspension array or multiplex PCR, however suspension array technology offered improved sensitivity, may be more accurate and could give time and cost savings.

CONCLUSIONS

Suspension array technology offers a rapid and high-throughput method for Y chromosome microdeletion screening in infertile men.