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Objective: This study aimed to investigate the genetic etiology of male infertility patients., Method: A total of 1600 male patients with infertility, including 1300 cases of azoospermia and 300 cases of severe oligozoospermia, underwent routine semen analysis, chromosomal karyotype analysis and sex hormone level testing. The Azoospermia factor (AZF) on the Y chromosome was detected using the multiple fluorescence quantitative PCR technique. Additionally, copy number variation (CNV) analysis was performed on patients with Sertoli-cell-only syndrome who had a normal karyotype and AZF., Result: Chromosomal abnormalities were found in 334 cases (20.88 %) of the 1600 male infertility patients. The most common type of abnormality was sex chromosome abnormalities (18.94 %), with 47, XXY being the most frequent abnormal karyotype. The rates of chromosomal abnormalities were significantly different between the azoospermia group and the severe oligospermia group (23.69 % and 8.67 %, respectively; P<0.05). AZF microdeletions were detected in 155 cases (9.69 %), with various deletion types and AZFc region microdeletion being the most prevalent. The rates of AZF microdeletions were not significantly different between the azoospermia group and the severe oligospermia group (9.15 % and 12 %, respectively; P=0.133). In 92 patients with Sertoli-cell-only syndrome who had a normal karyotype and AZF, the detection rate of CNV was 16.3 %. Compared to the severe oligospermia group, the azoospermia group had higher levels of FSH and LH and lower levels of T and E2, and the differences were statistically significant (P<0.05)., Conclusions: Male infertility is a complex multifactorial disease, with chromosomal abnormalities and Y chromosome microdeletions being important genetic factors leading to the disease. Initial genetic testing of infertile men should include karyotyping and Y chromosome microdeletions. If necessary, CNV testing should be performed to establish a clinical diagnosis and provide individualized treatment for male infertility., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Testing for AZoospermia Factor (AZF) deletions of the Y chromosome is a key component of the diagnostic workup of azoospermic and severely oligozoospermic men. This revision of the 2013 European Academy of Andrology (EAA) and EMQN CIC (previously known as the European Molecular Genetics Quality Network) laboratory guidelines summarizes recent clinically relevant advances and provides an update on the results of the external quality assessment program jointly offered by both organizations. A basic multiplex PCR reaction followed by a deletion extension analysis remains the gold-standard methodology to detect and correctly interpret AZF deletions. Recent data have led to an update of the sY84 reverse primer sequence, as well as to a refinement of what were previously considered as interchangeable border markers for AZFa and AZFb deletion breakpoints. More specifically, sY83 and sY143 are no longer recommended for the deletion extension analysis, leaving sY1064 and sY1192, respectively, as first-choice markers. Despite the transition, currently underway in several countries, toward a diagnosis based on certified kits, it should be noted that many of these commercial products are not recommended due to an unnecessarily high number of tested markers, and none of those currently available are, to the best of our knowledge, in accordance with the new first-choice markers for the deletion extension analysis. The gr/gr partial AZFc deletion remains a population-specific risk factor for impaired sperm production and a predisposing factor for testicular germ cell tumors. Testing for this deletion type is, as before, left at the discretion of the diagnostic labs and referring clinicians. Annual participation in an external quality control program is strongly encouraged, as the 22-year experience of the EMQN/EAA scheme clearly demonstrates a steep decline in diagnostic errors and an improvement in reporting practice., (© 2023 The Authors. Andrology published by Wiley Periodicals LLC on behalf of American Society of Andrology and European Academy of Andrology.)

Background: The incidence of Y chromosome microdeletions varies among men with infertility across regions and ethnicities worldwide. However, comprehensive epidemiological studies on Y chromosome microdeletions in Chinese men with infertility are lacking. We aimed to investigate Y chromosome microdeletions prevalence among Chinese men with infertility and its correlation with intracytoplasmic sperm injection (ICSI) outcomes., Methods: This single-center retrospective study included 4,714 men with infertility who were evaluated at the Reproductive Center of the First Affiliated Hospital of Sun Yat-sen University between May 2017 and January 2021. Semen analysis and Y-chromosome microdeletion via multiplex polymerase chain reaction were conducted on the men. The study compared outcomes of 36 ICSI cycles from couples with male azoospermia factor (AZF)cd deletions with those of a control group, which included 72 ICSI cycles from couples without male Y chromosome microdeletions, during the same period. Both groups underwent ICSI treatment using ejaculated sperm., Results: Among 4,714 Chinese men with infertility, 3.31% had Y chromosome microdeletions. The combined deletion of sY254 and sY255 in the AZFc region and sY152 in the AZFd region was the prevalent pattern of Y chromosome microdeletion, with 3.05% detection rate. The detection rates of AZF deletions in patients with normal total sperm count, mild oligozoospermia, severe oligozoospermia, cryptozoospermia, and azoospermia were 0.17%, 1.13%, 5.53%, 71.43%, and 7.54%, respectively. Compared with the control group, the AZFcd deletion group exhibited no significant difference in the laboratory results or pregnancy outcomes of ICSI cycles using ejaculated sperm., Conclusions: This is the largest epidemiological study on Y chromosome microdeletions in Chinese men with infertility. The study results underline the necessity for detecting Y chromosome microdeletion in men with infertility and severe sperm count abnormalities, especially those with cryptozoospermia. The combined deletion of sY254 and sY255 in the AZFc region and sY152 in the AZFd region was the most prevalent Y chromosome microdeletion pattern. Among patients with AZFcd deletion and ejaculated sperm, ICSI treatment can result in pregnancy outcomes, similar to those without AZFcd deletion., (© 2023. The Author(s).)

Deletion of the azoospermia factor c (AZFc), located on the long arm of the Y chromosome, is a cause of male infertility. The structure of the Y chromosome is diversified by the copy number of various genes, such as deleted in azoospermia (DAZ), basic protein Y2, chromodomain Y1, testis-specific transcript Y-linked 4, and Golgi autoantigen golgin subfamily a2 like Y, located in the AZF region. In this study, we investigated the deletion of each gene copy and analyzed its relationship with Japanese male infertility. Deletions of single nucleotide variants of each gene copy in 721 proven fertile men as controls, 139 patients with non-obstructive azoospermia (NOA), and 56 patients with oligozoospermia (OS) were analyzed via polymerase chain reaction-restriction fragment length polymorphism analysis. Their association with infertility was analyzed using logistic regression analysis adjusted for the Y-chromosome haplogroup, D1a2a. Deletions of DAZ/II in the r1 region and DAZ/V in the r1 and r2 regions showed significant associations with NOA (odds ratio [OR] = 4.15, 95 % confidence interval [CI] = 1.18-14.6, P = 0.026; OR = 4.19, 95 % CI = 1.19-14.7, P = 0.025, respectively). They did not show any association with OS. Partial deletion of the AZFc region affects spermatogenesis in Japanese male., Competing Interests: Declaration of Competing Interest The authors declare that there is no conflict of interest., (Copyright © 2023 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier B.V. All rights reserved.)

In this study, we aimed to elucidate the relationship between AZF deletion type and clinical information of azoospermic patients with AZF microdeletion in the Turkish population. Azoospermic patients with normal karyotype and AZF microdeletion were analysed retrospectively by collecting clinical data including hormone profile, demographic characteristics and micro-TESE results. As a result of the AZF microdeletion tests of 42 cases with 46 XY karyotype, AZFa deletion was detected in 3 cases, AZFb deletion in 2 cases, AZFc deletion in 31 cases, AZFb + AZFc deletion in 4 cases and AZFa + AZFb + AZFc deletion in 2 cases respectively. Spermatozoon was obtained in 16 cases with AZFc microdeletion with micro-TESE. Pregnancy was achieved in 2 cases. There was no statistically significant difference between the type of deletion and age, height, weight, body mass index, hormone profile and testicular volume. When AZF is evaluated according to the type of microdeletion, it will be appropriate to plan the medical and surgical options more carefully in a multidisciplinary manner in cases with deletions including AZFa, AZFb or their combinations. Also, genotype-phenotype correlation was found to be consistent with the literature; particularly patients having AZFc deletions were found to have a chance for pregnancy., (© 2021 Wiley-VCH GmbH.)

Introduction: In our study, we sought answers to many questions about male infertility from a different perspective. The first step in male infertility is anamnesis, physical examination and sperm count. The European Academy of Andrology recommends examination of genetic causes in individuals with fewer than 5million/ml semen counts. The American Urological Association and American Society for Reproductive Medicine have guidelines recommending performing karyotype and AZF subgroup deletion testing in azoospermia and fewer than 5 million sperm total count. Klinefelter syndrome and Y chromosome microdeletions are still very important in male infertility. Based on patients with Klinefelter syndrome or Y microdeletion, we sought answers to many questions in male infertility., Materials and Methods: In the presented study 327 male patients with having fewer than 15millionsperm/ml detected in at least two consecutive sperm analysis were examined. Patients were divided into sub-groups according to the presence of semen count, chromosomal anomaly and Y microdeletion. In addition, FSH, LH and testosterone levels were analyzed., Results: Numerical chromosomal anomalies were observed in 34 (10.4%) of 327 patients, and all of these anomalies were found as 47, XXY. Individuals with no AZF microdeletion constituted 95.1% (n=311) of the study group. The overall frequency of AZF microdeletions was 4.9% (16/327). No AZF microdeletions were detected for the patients who have sperm counts above 2million/ml. FSH, LH and testosterone levels were found significantly different between the groups., Discussion: The results of our study provide another layer of evidence to demonstrate the controversial threshold value of the EAA. In light of our data and current literature, we recommend to set the threshold value at 2million/ml for semen analysis. Further studies conducted in different ethnic groups and larger patient groups would contribute to clarify what exact value should be used to apply genetic tests., (Copyright © 2019 Asociación Española de Andrología, Medicina Sexual y Reproductiva. Publicado por Elsevier España, S.L.U. All rights reserved.)

Azoospermia factor (AZF) microdeletion plays a key role in the genetic etiology of male infertility. The relationship between sY152 deletion in the AZFc region and clinical outcomes is still unclear. This study was to determine the effects of sY152 deletion on the sperm parameters and clinical outcomes of non-obstructive azoospermia or oligozoospermia men after intracytoplasmic sperm injection (ICSI) treatment. A total of 61 infertile men with AZFc microdeletion of the Y chromosome from January 2008 to December 2012 were recruited in the present study. They were divided into two groups, the sY152 group (n=12) and the AZFc group (n=49), based upon whether they have deleted single sY152 marker or all AZFc markers. Fifty azoospermia or oligozoospermia patients without Y chromosome microdeletion were included as the control group. The sperm quality and clinical data were compared among the three groups. Retrospective cohort-control study was performed. The sperm concentration and motility in sY152 group were better than AZFc group (P<0.05), and were comparable to the control group (P>0.05); the morphology, seminal zinc, seminal fructose and seminal carnitine were similar among the three groups (P>0.05). Patients in both sY152 and AZFc groups had lower fertilization rates (68.40% and 70.63%, respectively) than those in the control group (74.91%), and the differences were statistically significant (P<0.05). No significant differences were found in terms of MII oocyte, high-grade embryo rate, 2PN zygote, number of available embryos and transferred embryos, clinical pregnancy rate, implantation rate, miscarriage rate, multiple pregnancy rate, delivery rate, preterm rate and the male/female ratio among the three groups (P>0.05). Single sY152 deletion might cause a lower fertilization rate, but no adverse effects on sperm quality and clinical outcomes were found. Our study may provide more information for consultation in these patients., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Background: To optimize the multiplex polymerase chain reaction (M-PCR) technique to diagnose microdeletions of azoospermia factors (AZF) on the Y chromosome and initially apply the technique to diagnose male patients with sperm density less than 5× 106 million sperm/mL was assigned to do a test to check for AZF microdeletions on the Y chromosome. Methods: Based on the positive control samples which belong to male subjects who have had 2 healthy children without any assisted reproductive technologies, the M-PCR method was developed to detect simultaneously and accurately AZF microdeletions on 32 male patients with sperm densities below 5× 106 million sperm/mL of semen at the Department of Biology and Medical Genetics – Vietnam Military Medical University. Results: Successful optimization of the M-PCR technique including 7 reactions arranged according to each AZFabc region using 24 STS/gene on the Y chromosome. Initial application to diagnose AZF deletion on 32 azoospermic and oligospermic men reveals that AZFa deletion accounts for 6.25% (2/32); deletion of all 3 regions AZFa,b,c with 18.75% (6/32 cases); The combined deletion rate of AZFb,c is highest, accounting for 56.24% (18/32 patients). Conclusion: Successfully optimized the M-PCR technique in identifying AZF microdeletions using 24 sequence tagged sites (STS)/gene for azoospermic and oligozoospermic men. The M-PCR technique has great potential in the application of AZF deletion diagnosis. [ABSTRACT FROM AUTHOR]

Microdeletions of Y chromosomes frequently occur in 3 subregions of the AZF, namely, AZFa, AZFb, and AZFc, with 6 basic STS marker sequences, which are sY84, sY86 (AZFa), sY127, sY134 (AZFb), and sY254, sY255 (AZFc). According to EAA/EMNQ guidelines, 11 additional AZFabc marker sequences should be used to determine the extent of the microdeletion in the AZF region of infertile men, which is known as 11 extended STSs. By applying mPCR, the authors develop an optimal detection procedure for the 6 basic STS and 11 extended STS using 3 multiplex PCR reactions. The first multiplex PCR reaction includes 6 basic STS plus the 2 control sequences sex-determining region Y (SRY) and zinc finger protein X/Y-linked (ZFX/Y). The second multiplex PCR reaction includes the 6 extended STS sY88, sY1182, sY105, sY121, sY1191, and sY1291 and the 2 control sequences SRY and ZFX/Y. The third multiplex PCR reaction includes the 5 extended STS sY153, sY160, sY82, sY143, and sY83 and the 2 control sequences SRY and ZFX/Y. Six basic primer sequences and eleven extended primer sequences are redesigned to simultaneously pair and amplify STS in the same multiplex reaction: set of 8 primers for 6 basic STS: 6 basic STS + 2 (SRY, ZFX/Y), 8 extension primers set E1: 6 extended STS + 2 (SRY, ZFX/Y), and 7 extension primers set E2: 5 extended STS + 2 (SRY, ZFX/Y). We successfully designed primer pairs with high specificity and stability and successfully amplified 6 basic STS and 11 extended STS, which ensures that the STSs have the correct sequence as recommended by EAA/EMQN and are consistent with the NCBI gene bank. This study has successfully developed a procedure to simultaneously detect 17 STSs, including 6 basic STSs and 11 extended STSs in the AZF region using 3 multiplex PCR reactions.

The aim of this study was to establish the prevalence of chromosomal abnormalities and microdeletions on the Y chromosome in Tunisian infertile men with severe oligozoospermia or non-obstructive azoospermia. In cases of azoospermia, we aimed also to correlate histological results after negative testicular sperm extraction with the type of Y chromosome microdeletion. 84 infertile patients and 52 controls were screened for karyotypic abnormalities using G-banding and Yq chromosome microdeletions using multiplex PCR. 7 infertile males (8.3%) carried chromosomal abnormalities and 8 (9.5%) presented Y chromosome microdeletions. The frequency of chromosome abnormalities in azoospermic patients was 11.1% vs 3.3% in the severe oligozoospermic group. Klinefelter syndrome was the most frequent chromosomal abnormalities in 85.7% of cases. Only one patient had a 46,X,del Y/45,X karyotype. The frequency of microdeletions was 11.1% in the azoospermic group and 6.7% in the severe oligozoospermic group. Six out of 84 (7.14%) of the infertile patients had microdeletions in the AZFc region, one azoospermic male had microdeletion in the AZFbc regions and one in the AZFb region, no deletions in the AZFa region. Among the 6 azoospermic patients with microdeletions: 4 had Sertoly cell only syndrome (SCOS) and 2 had maturation arrest (MA). Genetic abnormalities in infertile Tunisian patients are similar to those reported in other countries. The knowledge of the existence of genetic abnormalities and microdeletions is useful to provide a correct diagnosis and it allows the clinician to refer the patient to adequate assisted reproduction technique and examine the value of testicular biopsy pertinence. [ABSTRACT FROM AUTHOR]

We present a rare male fetus with karyotype of mosaic 45,X that comprises two types of aberrant Y chromosomes arising de novo (Yq12 deletion and isodicentric Yq11.22). Both types of the aberrant Y chromosomes lack the AZFc region which are expected to result in oligospermia but unaffected male external genitalia. Genetic analyses by karyotyping, chromosome microarray (CMA), and multiplex ligation-dependent probe amplification (MLPA) for the fetus revealed conflicting results. Additional molecular cytogenetics tools including fluorescence in situ hybridization (FISH) and multicolor banding (mBAND) were performed, which help resolving the discrepancy and delineated the composition of the aberrant Y chromosomes. This report highlighted the importance of incorporating multiple genetic technologies for accurate characterization of complex chromosomal rearrangements, which aid in the prenatal diagnosis and genetic counseling. [ABSTRACT FROM AUTHOR]

Background: The microdeletion events that occur in the Y chromosome-azoospermia factor (AZF) region may lead to dyszoospermia. Also, the deleted azoospermia (DAZ) gene on AZFc and autosomal deleted azoospermia like gene (DAZL) are suggested to represent impairment, so it is interesting to determine the independency pattern of the AZF region and DAZL gene in azoospermic patients. Aim: To study the molecular characterization of AZFc and DAZL in 64 idiopathic non-obstructed azoospermia patients and 30 sexually reproductive men. Methods: SYBR Green I (Q-PCR) and AZF-STS analysis was used for DAZ gene, and SNV-PCR and confirmative Sanger sequencing for DAZL gene. Results: The present study observed that 15.6% had AZFc microdeletion, out of which 10% had DAZ1/2 deletion, and no T54A variant in the DAZL gene was found. Conclusion: In the current work, the novelty is that spermatogenic impairment phenotype, present with AZFc microdeletions, is independent of the T54A variant in the DAZL gene, and AZFc microdeletions could be a causative agent in spermatogenic impairment. [ABSTRACT FROM AUTHOR]

The molecular diagnosis of Y-chromosomal microdeletions is a common routine genetic test which is part of the diagnostic workup of azoospermic and severe oligozoospermic men. Since 1999, the European Academy of Andrology ( EAA) and the European Molecular Genetics Quality Network ( EMQN) have been actively involved in supporting the improvement of the quality of the diagnostic assays by publication of the laboratory guidelines for molecular diagnosis of Y-chromosomal microdeletions and by offering external quality assessment trials. The present revision of the 2004 laboratory guidelines summarizes all the clinical novelties related to the Y chromosome (classic, partial and gene-specific deletions, genotype-phenotype correlations, methodological issues) and provides an update on the results of the quality control programme. These aspects also reflect the consensus of a large group of specialists present at a round table session during the recent Florence-Utah-Symposium on 'Genetics of male infertility' (Florence, 19-21 September, 2013). During the last 10 years the gr/gr deletion has been demonstrated as a significant risk factor for impaired sperm production. However, the screening for this deletion type in the routine diagnostic setting is still a debated issue among experts. The original basic protocol based on two multiplex polymerase chain reactions remains fully valid and appropriate for accurate diagnosis of complete AZF deletions and it requires only a minor modification in populations with a specific Y chromosome background. However, in light of novel data on genotype-phenotype correlations, the extension analysis for the AZFa and AZFb deletions is now routinely recommended. Novel methods and kits with excessively high number of markers do not improve the sensitivity of the test, may even complicate the interpretation of the results and are not recommended. Annual participation in an external quality control programme is strongly encouraged. The 12-year experience with the EMQN/ EAA scheme has shown a steep decline in diagnostic (genotyping) error rate and a simultaneous improvement on reporting practice. [ABSTRACT FROM AUTHOR]

Purpose: Yq microdeletions are the leading genetic cause of male infertility and its detection is clinically relevant for appropriate genetic counseling. We aimed to determine the prevalence and type of Yq microdeletions, the associated seminal phenotypes and the STS markers that are relevant for its testing in Indian population. Methods: Yq microdeletion analysis was carried out in 1,636 infertile cases in our centers. Additional data was collected from published studies in Indian population leading to a total of 3,647 cases. Results: In our cohort, 3.4 % (56/1,636) of infertile men had Yq microdeletions. Combining the data from other published studies identified 215/3,647 (5.8 %) infertile individuals to harbor Yq microdeletions; with 6.4 % in azoopsermia, 5.8 % in oligozoospermia and 3.2 % in oligoasthenozoospermia and teratozoospermia cases. No significant differences in the deletion frequencies were observed between idiopathic vs non idiopathic cases (5.8 vs 8.6 % respectively). Deletions of AZFc were at highest frequency (46.6 %) with double deletions most commonly observed in azoospermic subjects. With respect to the STS markers, screening with the six European Academy of Andrology (EAA) markers would miss 3.1 % of cases; additional non EAA markers that would contribute significantly to screening are sY746, sY82, sY121, sY128, sY130, sY143, sY145 & sY160. Interpretations and conclusions: The frequency of Yq microdeletions is lower in Indian population as compared to Western counterparts. There is no major association of Yq microdeletions with seminal parameters or cause of infertility. Clinically it will be necessary to offer Yq microdeletion testing to all the classes of infertile men. The EAA markers may not be adequate to detect microdeletions in Indian infertile men. [ABSTRACT FROM AUTHOR]

Abstract summary: Detection of Y-chromosome microdeletion is useful to obtain reliable genetic information for assisted reproductive techniques, thus avoiding unnecessary treatment and vertical transmission of genetic defects. Purposes: This research was conducted over a six-year period to analyze clinical data, somatic cytogenetic abnormalities, and types of microdeletions in men with fertility disorders in Iran. Methods and Patients: A total of 3654 infertile men were included in this study. Semen samples were analyzed according to standard methods. Conventional chromosomal karyotyping was used to analyze chromosome abnormalities. Polymerase chain reaction (PCR) amplification using nine specific sequence-tagged sites (STS) was used to detect AZF microdeletions. Results: Out of the 3654 patients who were analyzed, AZF region microdeletions were detected in 185 cases (5.06 %). Karyotype analysis was available for 157 men and among them abnormal karyotypes were found in 51 cases (32.48 %). One hundred and forty-seven cases with Yq microdeletions suffered from azoospermia and 38 from severe oligozoospermia. Our data show that the most frequent microdeletions were in the AZFc region, followed by the AZFb + c + d, AZFb + c, AZFb, AZFa, and AZF a + c regions. Conclusion: The study has confirmed that the detection of microdeletions in the AZF region is significant from a diagnostic viewpoint. It is also useful to obtain reliable genetic information from infertile men to determine the etiology of the deletions, and to avoid unnecessary treatments and vertical transmission of genetic defects. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Genomic disorders are defined as diseases caused by rearrangements of the genome incited by a genomic architecture that conveys instability. Y-chromosome related dysfunctions such as male infertility are frequently associated with gross DNA rearrangements resulting from its peculiar genomic architecture. The Y-chromosome has evolved into a highly specialized chromosome to perform male functions, mainly spermatogenesis. Direct and inverted repeats, some of them palindromes with highly identical nucleotide sequences that can form DNA cruciform structures, characterize the genomic structure of the Y-chromosome long arm. Some particular Y chromosome genomic deletions can cause spermatogenic failure likely because of removal of one or more transcriptional units with a potential role in spermatogenesis. We describe mechanisms underlying the formation of human genomic rearrangements on autosomes and review Y-chromosome deletions associated with male infertility. [ABSTRACT FROM AUTHOR]

BACKGROUND: The relationship between male infertility and gr/gr deletions that remove multiple genes of the Y chromosome varies among countries and populations. The aim of this study was to investigate the association between gr/gr deletions and spermatogenic phenotype in fertile and infertile Japanese men. METHODS: The subjects were screened by sequence-tagged site (STS) analysis to detect gr/gr deletions, and haplogroups were assigned using eight highly informative markers. In total, 395 infertile men and 377 fertile men (controls) participated in our study. Of the 772 subjects, 260 individuals carried confirmed gr/gr deletions and were used in further analysis of deletion subtype and gene copy number, specifically loss and gain of CDY1 and DAZ copies. These 260 subjects were divided into a control group (n = 131) all with normozoospermia, and an infertile group (n =129) with 89 infertile subjects exhibiting azoospermia (absence of sperm) and 40 exhibiting oligozoospermia (reduced sperm concentration). RESULTS: There were gr/gr deletions in 33.7% (260/772) of all subjects and the deletions were widespread in haplogroup D (86.2%). There were no significant differences in the frequency of gr/gr deletions between the infertile and control groups. The gr/gr deletion subtypes were not distributed randomly among haplogroups; the CDY1a + DAZ1/2 genes were deleted in 96.9% (217/224) of haplogroup D individuals, whereas the O lineage had a variety of gr/gr deletion types. The loss of CDY1a + DAZ1/2 was not associated with spermatogenic impairment in haplogroup D (P = 0.33). CONCLUSIONS: Taken together, gr/gr deletions in haplogroup D occur constitutively, are associated with the loss of CDY1a + DAZ1/2 and are phenotypically neutral. Further studies are needed to establish whether Y-linked compensatory factors outside the AZFc region can counteract the pathogenic effect of a gr/gr deletion in the D lineage. [ABSTRACT FROM AUTHOR]

Background & objectives: Genetic factors contribute about 10 per cent of male infertility. Among these, genes in azoospermia factor (AZF) region including AZFa, AZFb, AZFc and AZFd on the long arm of Y chromosome are considered most important for spermatogenesis. Deletions in these regions are thought to be involved in some cases of male infertility associated with azoospermia or oligozoospermia. We studied the incidence of AZF deletions among Iranian infertile men with idiopathic non-obstructive azoospermia. Methods: A total of 100 Iranian azoospermic infertile men were selected for the molecular study of Y chromosome microdeletions. The presence of 13 sequence tagged site (STS) markers from AZF region was investigated using multiplex polymerase chain reaction (M-PCR). One hundred fertile men were also studied as control group. Results: Twelve (12%) patients showed Y chromosome microdeletions and among these, deletion in AZFb region was the most frequent (66.67%) followed by AZFc (41.67%), AZFd (33.33%) and AZFa (8.33%), respectively. Interpretation & conclusions: Because of relatively high incidence of Y chromosome microdeletions among Iranian azoospermic patients, molecular screening may be advised to infertile men before using assisted reproductive treatments. [ABSTRACT FROM AUTHOR]

The aim of this study was to establish the prevalence of Y chromosomal microdeletions in infertile Tunisian men. Three groups of infertile men, 65 normospermic, 53 oligozoospermic and 45 azoospermic, were tested for Yq microdeletions detection by multiplex polymerase chain reaction (PCR) using specific Y chromosome AZF regions tagged site markers (STS). One group of 13 healthy men was used as the control group. Six STS were tested (2 in each AZF region). The general prevalence of AZF microdeletions was 16%; in azoospermia and severe oligospermia groups, it was higher (29% and 30.5%, respectively). Significant differences were found with moderate oligospermic and normospermic groups (p [ABSTRACT FROM AUTHOR]

Objective: To investigate microdeletions and palindrome complexes in the azoospermic factor (AZF) c regions of the Y chromosome, by polymerase chain reaction (PCR) with sequence-tagged site (STS) markers with known physical positions, after verification of the exact physical locations of candidate STSs and exclusion of those that would give ambiguous results on PCR. Design: Retrospective STS deletion study in infertile Japanese men. Setting: University hospital and reproductive clinic. Patient(s): A total of 410 men with nonobstructive azoospermia and severe oligospermia (sperm concentrations of <5 × 106/mL). Intervention(s): Polymerase chain reaction was performed for all STS markers confirmed to be physically located in the partial AZFb and AZFc regions of the Y chromosome. All STSs were retrieved from the University of California at Santa Cruz database, and their location and specificity were verified. Main Outcome Measure(s): Presence or absence of appropriately sized PCR products. Result(s): Sixty-nine markers were retrieved, 32 of which were not specific to the long arm of the Y chromosome (Yq). The markers retained for test use were contiguous deletions classified as P1+P2 (AZFc) or P3 proximal/P1 (AZFb+c). The prevalence of accurately mapped microdeletions was 5.1% (21 of 410) in this patient population. Conclusion(s): Although noncontiguous deletions were observed, considerable confusion remained until the genome sequence was finally determined because many of the STSs were either repetitive sequences or polymorphic between individuals or races. [Copyright &y& Elsevier]

The multiplex STS-PCR method was used to detect microdeletions in the long arm of the Y chromosome (Yq) of cytogenetically normal men. One hundred infertile men with azoospermia or oligozoospermia were screened with the multiplex PCR method using 58 STSs, which are specific to Yq for detecting microdeletions on this chromosome. Correlations between the microdeletions on Yq and phenotypes of spermatogenetic disturbance were also examined. Ten patients (10%) had microdeletions on Yq. Seven of the 60 azoospermic patients (11.7%), and 3 of the 40 oligozoospermic patients (7.5%) had microdeletions on Yq. None of the patients showed microdeletions in the AZFa region, but 2 had deletions in the AZFb region, another 2 in the AZFc region, including DAZ, and 1 had deletions in both the AZFb and in the AZFc, including RBM and DAZ. Single microdeletions were found in 4 patients, all of them in the AZFc around DAZ, and 1 patient had 2 microdeletions in the AZFb. The improved multiplex STS-PCR method efficiently detected microdeletions in 10% of azoospermic or severe oligozoospermic men who were cytogenetically normal. All of these microdeletions were presented in the AZFb and/or AZFc regions. This suggests that these regions contain candidate genes for spermatogenesis. [ABSTRACT FROM AUTHOR]

Microdeletions of the so-called azoospermia factor (AZF) locus of the Y chromosome long arm (Yq) are an etiological factor of severe oligozoospermia or azoospermia. Patients affected are infertile unless assisted reproductive techniques are used. We report the case of an azoospermic patient (proband) and three brothers who inherited a Yq microdeletion from their father through a spontaneous pregnancy. Leukocyte DNA was extracted using a commercially available kit. A total of 15 pairs of sequence-tagged site (STSs) based primers, spanning the AZFa, b and c regions, were used for screening. All brothers and their father carried a Yq microdeletion of the AZFb subregion where the RNA-binding motif (RBM) gene is located. The proband carried additional deletions of the AZFa and AZFb subregions. RBM deletion can be associated with oligozoospermia allowing natural conception and therefore natural transmission of this genetic anomaly. [ABSTRACT FROM AUTHOR]