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Although hundreds of knockout mice show infertility as a major phenotype, the causative genic mutations of male infertility in humans remain rather limited. Here, we report the identification of a missense mutation (D136G) in the X-linked TAF7L gene as a potential cause of oligozoospermia in men. The human aspartate (D136) is evolutionally conserved across species, and its change to glycine (G) is predicted to be detrimental. Genetic complementation experiments in budding yeast demonstrate that the conserved aspartate or its analogous asparagine (N) residue in yeast TAF7 is essential for cell viability and thus its mutation to G is lethal. Although the corresponding D144G substitution in the mouse Taf7l gene does not affect male fertility, RNA-seq analyses reveal alterations in transcriptomic profiles in the Taf7l (D144G) mutant testes. These results support TAF7L mutation as a risk factor for oligozoospermia in humans., (© The Author(s) 2022. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Non-obstructive azoospermia accounts for 10-15% of male infertility, resulting in 60% of all cases of azoospermia and affecting about 1% of the male population. About 30% of these cases are due to Y chromosome microdeletions, chromosome abnormalities, or hormonal disorders. Pathogenic variants in genes on the sex chromosomes have key roles in spermatogenic failure. The co-occurrence of azoospermia and congenital cataracts ranges between 1 in 165,000 and 1 in 500,000. Our 28-year-old patient with normal intelligence and abnormally shaped teeth presented with both disorders. A microarray revealed a microdeletion at Xp23.13 with a whole NHS gene deletion as well as a contiguous deletion of two other genes [SCML1 and RAI2]. This observation represents the first report of non-obstructive azoospermia with congenital cataracts and a contiguous deletion of the SCML1 gene, a transcript of which is exclusively expressed in the testis. SCML1 is the putative culprit gene, which requires functional study or animal experiments. Our analysis of 60 known spermatogenesis failure-related genes by whole-exome sequencing revealed no other candidate. The Nance-Horan syndrome due to pathogenic variants in the NHS gene at Xp23.13 including whole gene deletion does not have azoospermia as a feature. Our report adds to the completeness of genetic counseling for an individual with azoospermia and congenital cataracts.

This monograph, written by the pioneers of IVF and reproductive medicine, celebrates the history, achievements, and medical advancements made over the last 40 years in this rapidly growing field., (Copyright © 2018 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)

Background: Herein, we describe the consensus guideline methodology, summarize the evidence-based recommendations we provided to the World Health Organization (WHO) for their consideration in the development of global guidance and present a narrative review of the diagnosis of male infertility as related to the eight prioritized (problem or population (P), intervention (I), comparison (C) and outcome(s) (O) (PICO)) questions. Additionally, we discuss the challenges and research gaps identified during the synthesis of this evidence., Objective and Rationale: The aim of this paper is to present an evidence-based approach for the diagnosis of male infertility as related to the eight prioritized PICO questions., Search Methods: Collating the evidence to support providing recommendations involved a collaborative process as developed by WHO, namely: identification of priority questions and critical outcomes; retrieval of up-to-date evidence and existing guidelines; assessment and synthesis of the evidence; and the formulation of draft recommendations to be used for reaching consensus with a wide range of global stakeholders. For each draft recommendation the quality of the supporting evidence was then graded and assessed for consideration during a WHO consensus., Outcomes: Evidence was synthesized and recommendations were drafted to address the diagnosis of male infertility specifically encompassing the following: What is the prevalence of male infertility and what proportion of infertility is attributable to the male? Is it necessary for all infertile men to undergo a thorough evaluation? What is the clinical (ART/non ART) value of traditional semen parameters? What key male lifestyle factors impact on fertility (focusing on obesity, heat and tobacco smoking)? Do supplementary oral antioxidants or herbal therapies significantly influence fertility outcomes for infertile men? What are the evidence-based criteria for genetic screening of infertile men? How does a history of neoplasia and related treatments in the male impact on (his and his partner's) reproductive health and fertility options? And lastly, what is the impact of varicocele on male fertility and does correction of varicocele improve semen parameters and/or fertility?, Wider Implications: This evidence synthesis analysis has been conducted in a manner to be considered for global applicability for the diagnosis of male infertility., (© The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology.)

As men age, medical and surgical diseases involving the genitourinary tract become more common. The conditions themselves, if not their treatments, can negatively impact the fertility potential of an affected man. Many older men maintain the desire to father children, so it is critical to understand the disturbed anatomy and physiology involved to properly counsel that individual. Should this or that treatment regimen be employed? Should sperm banking be undertaken before institution of a permanently ablative/suppressive therapy? What are the long-term consequences of one therapy over another vis-à-vis sperm production, sperm quality, and/or sperm transport? In this context, some of the more common genitourinary afflictions of the older male and the treatment options that are available will be discussed., (Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)

Genome-wide recombination is essential for genome stability, evolution, and speciation. Mouse Tex11, an X-linked meiosis-specific gene, promotes meiotic recombination and chromosomal synapsis. Here, we report that TEX11 is mutated in infertile men with non-obstructive azoospermia and that an analogous mutation in the mouse impairs meiosis. Genetic screening of a large cohort of idiopathic infertile men reveals that TEX11 mutations, including frameshift and splicing acceptor site mutations, cause infertility in 1% of azoospermic men. Functional evaluation of three analogous human TEX11 missense mutations in transgenic mouse models identified one mutation (V748A) as a potential infertility allele and found two mutations non-causative. In the mouse model, an intronless autosomal Tex11 transgene functionally substitutes for the X-linked Tex11 gene, providing genetic evidence for the X-to-autosomal retrotransposition evolution phenomenon. Furthermore, we find that TEX11 protein levels modulate genome-wide recombination rates in both sexes. These studies indicate that TEX11 alleles affecting expression level or substituting single amino acids may contribute to variations in recombination rates between sexes and among individuals in humans., (© 2015 The Authors. Published under the terms of the CC BY 4.0 license.)

Deletions involving the Y chromosome's AZFc region are the most common known genetic cause of severe spermatogenic failure (SSF). Six recurrent interstitial deletions affecting the region have been reported, but their population genetics are largely unexplored. We assessed the deletions' prevalence in 20,884 men in five populations and found four of the six deletions (presented here in descending order of prevalence): gr/gr, b2/b3, b1/b3, and b2/b4. One of every 27 men carried one of these four deletions. The 1.6 Mb gr/gr deletion, found in one of every 41 men, almost doubles the risk of SSF and accounts for ∼2% of SSF, although <2% of men with the deletion are affected. The 1.8 Mb b2/b3 deletion, found in one of every 90 men, does not appear to be a risk factor for SSF. The 1.6 Mb b1/b3 deletion, found in one of every 994 men, appears to increase the risk of SSF by a factor of 2.5, although <2% of men with the deletion are affected, and it accounts for only 0.15% of SSF. The 3.5 Mb b2/b4 deletion, found in one of every 2,320 men, increases the risk of SSF 145 times and accounts for ∼6% of SSF; the observed prevalence should approximate the rate at which the deletion arises anew in each generation. We conclude that a single rare variant of major effect (the b2/b4 deletion) and a single common variant of modest effect (the gr/gr deletion) are largely responsible for the AZFc region's contribution to SSF in the population., (Copyright © 2012 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

Massive palindromes in the human Y chromosome harbor mirror-image gene pairs essential for spermatogenesis. During evolution, these gene pairs have been maintained by intrapalindrome, arm-to-arm recombination. The mechanism of intrapalindrome recombination and risk of harmful effects are unknown. We report 51 patients with isodicentric Y (idicY) chromosomes formed by homologous crossing over between opposing arms of palindromes on sister chromatids. These ectopic recombination events occur at nearly all Y-linked palindromes. Based on our findings, we propose that intrapalindrome sequence identity is maintained via noncrossover pathways of homologous recombination. DNA double-strand breaks that initiate these pathways can be alternatively resolved by crossing over between sister chromatids to form idicY chromosomes, with clinical consequences ranging from spermatogenic failure to sex reversal and Turner syndrome. Our observations imply that crossover and noncrossover pathways are active in nearly all Y-linked palindromes, exposing an Achilles' heel in the mechanism that preserves palindrome-borne genes.

The human Y chromosome is replete with amplicons-very large, nearly identical repeats-which render it susceptible to interstitial deletions that often cause spermatogenic failure. Here we describe a recurrent, 1.8-Mb deletion that removes half of the azoospermia factor c (AZFc) region, including 12 members of eight testis-specific gene families. We show that this "b2/b3" deletion arose at least four times in human history-likely on inverted variants of the AZFc region that we find exist as common polymorphisms. We observed the b2/b3 deletion primarily in one family of closely related Y chromosomes-branch N in the Y-chromosome genealogy-in which all chromosomes carried the deletion. This branch is known to be widely distributed in northern Eurasia, accounts for the majority of Y chromosomes in some populations, and appears to be several thousand years old. The population-genetic success of the b2/b3 deletion is surprising, (i) because it removes half of AZFc and (ii) because the gr/gr deletion, which removes a similar set of testis-specific genes, predisposes to spermatogenic failure. Our present findings suggest either that the b2/b3 deletion has at most a modest effect on fitness or that, within branch N, its effect has been counterbalanced by another genetic, possibly Y-linked, factor.

Background: Severe spermatogenic compromise may be the result of a Y-chromosomal deletion of the AZFc region. Prior studies are limited to relatively small numbers of AZFc-deleted men. In this study, we have fully characterized 42 infertile men with a Y chromosome microdeletion strictly confined to the AZFc region, and we report on 18 children conceived through the use of ICSI., Methods: A total of 42 oligospermic or azoospermic men had AZFc deletions. History, physical examination, karyotype, FSH, LH, testosterone, testis histology and results of ICSI using ejaculated or testis sperm were retrospectively accumulated in two academic clinical practices., Results: All men were somatically healthy. Karyotypes were 46,XY in all but two men. FSH, LH, testosterone and testis histology could not differentiate those with oligospermia or azoospermia, nor could they predict whether sperm could be found in harvested testis tissue. Paternal age was not increased. Sperm production appeared stable over time. The results of ICSI were not affected by the AZFc deletion. All but one of the offspring were healthy. The sons inherited the AZFc deletion with no increase in length., Conclusions: AZFc-deleted men are somatically healthy, will most likely have useable sperm, will have stable sperm production over time and will have a good chance to experience biological paternity, but their sons will also be AZFc-deleted.

It is widely believed that at least three nonoverlapping regions of the human Y chromosome-AZFa, AZFb, and AZFc ("azoospermia factors" a, b, and c)-are essential for normal spermatogenesis. These intervals are defined by interstitial Y-chromosome deletions that impair or extinguish spermatogenesis. Deletion breakpoints, mechanisms, and lengths, as well as inventories of affected genes, have been elucidated for deletions of AZFa and of AZFc but not for deletions of AZFb or of AZFb plus AZFc. We studied three deletions of AZFb and eight deletions of AZFb plus AZFc, as assayed by the STSs defining these intervals. Guided by Y-chromosome sequence, we localized breakpoints precisely and were able to sequence nine of the deletion junctions. Homologous recombination can explain seven of these deletions but not the remaining two. This fact and our discovery of breakpoint hotspots suggest that factors in addition to homology underlie these deletions. The deletions previously thought to define AZFb were found to extend from palindrome P5 to the proximal arm of palindrome P1, 1.5 Mb within AZFc. Thus, they do not define a genomic region separate from AZFc. We also found that the deletions of AZFb plus AZFc, as assayed by standard STSs heretofore available, in fact extend from P5 to the distal arm of P1 and spare distal AZFc. Both classes of deletions are massive: P5/proximal-P1 deletions encompass up to 6.2 Mb and remove 32 genes and transcripts; P5/distal-P1 deletions encompass up to 7.7 Mb and remove 42 genes and transcripts. To our knowledge, these are the largest of all human interstitial deletions for which deletion junctions and complete intervening sequence are available. The restriction of the associated phenotype to spermatogenic failure indicates the remarkable functional specialization of the affected regions of the Y chromosome.

Objective: To describe a case involving the cryopreservation of testis tissue retrieved from a 15-year-old male teenager with Klinefelter's syndrome., Design: Case report., Setting: An academic medical center., Patient(s): A 15-year-old boy with Klinefelter's syndrome., Intervention(s): Microsurgical testis sperm extraction with cryopreservation of harvested tissue., Main Outcome Measure(s): Spermatozoa within testis tissue., Result(s): Successful extraction and cryopreservation of three vials of sperm-containing testis tissue. No effect on subsequent testosterone levels., Conclusion(s): Testis tissue extraction in the adequately virilized but azoospermic young male with 47, XXY Klinefelter's syndrome may be a strategy to preserve future biological paternity.

Testicular tissue extraction (TESE) to obtain spermatozoa for use with intracytoplasmic sperm injection (ICSI) has recently been employed in patients with non-obstructive azoospermia. Standard protocol is to retrieve a new sample of testis tissue on the day of oocyte recovery. Unfortunately, approximately 30% of men will possess no spermatozoa in their tissue, making ICSI an impossibility. We investigated whether testicular tissue that was intentionally obtained well before any planned ICSI cycle and cryopreserved could then serve as an efficacious sperm source in a subsequent ICSI cycle. This study reports on 10 men with non-obstructive azoospermia who did have spermatozoa found within their testis tissue at the time of TESE and who chose to use their frozen samples as the source of spermatozoa for a later cycle of ICSI. In 19 cycles the overall fertilization rate was 48%. Embryo transfer occurred in 89% of cycles. Two couples have achieved pregnancy (one ongoing, one delivered). All patients except one had multiple vials of frozen tissue remaining following their first cycle. This approach is offered as an alternative to repeated testicular tissue sampling, as the availability of spermatozoa is assured prior to the initiation of ovulation induction. This tissue can be harvested at the same time as diagnostic biopsy, thereby minimizing the number of surgical procedures.

Some men with non-obstructive azoospermia harbour fully formed spermatozoa within their testicular tissue that can be used to achieve pregnancy via intracytoplasmic sperm injection (ICSI). Recently, Reijo et al. (1995) provided compelling evidence that the DAZ gene cluster is a strong candidate for one of the elusive azoospermia factors (AZF) located on the long arm of the Y chromosome. The DAZ gene cluster is deleted in 13% of azoospermic men and a small percentage of severely oligozoospermic men. Vertical transmission from father to son of AZF region deletions has also been described. Presumably these fathers were oligozoospermic. This led us to ask whether the azoospermic male with deletions of the AZF/DAZ region can also complete minimal spermatogenesis and whether any spermatozoa found could participate in fertilization, embryo development and pregnancy. Three out of six (50%) of the azoospermic men with AZF/DAZ deletions had spermatozoa identified within their harvested testicular tissue. When these spermatozoa were used for ICSI, fertilization occurred in 36% of injected oocytes. This compared favourably with testicular spermatozoa retrieved from non-obstructive azoospermic men without AZF/DAZ gene deletions. In one case, a twin conception resulted, which represents the first term pregnancy reported using spermatozoa from an AZF/DAZ deleted azoospermic male. Therefore it is necessary to take the possibility of transmission of infertility or sterility to our patients' offspring seriously when utilizing today's reproductive technologies, as spermatogenesis in men with AZF/DAZ deletions is by no means an exceptional occurrence.

Microsurgical epididymal sperm aspiration was a great advance in the therapy of patients with non-reconstructable, obstructive azoospermia, most notably congenital bilateral absence of the vas deferens. Using conventional in-vitro fertilization, pregnancies were rarely achieved because the rate of oocyte fertilization was extremely poor. However, the use of retrieved spermatozoa in conjunction with intracytoplasmic sperm injection (ICSI) has dramatically increased the likelihood of embryo formation. Typically, sperm and oocyte harvesting are performed simultaneously. We have investigated whether frozen-thawed spermatozoa work as well as fresh spermatozoa. When we had concluded from our own population of patients (groups I and II) that they did, we adopted a policy of aspirating spermatozoa, primarily cryopreserving them and using them for ICSI at a later date. We found the fertilization rates of this latter cohort of patients (group III) to be excellent (37% per oocyte), and the ongoing pregnancy rate is quite satisfactory (40% per couple, 29% per cycle). We offer this approach as an alternative to the traditional scheme because it markedly eases the burden of partner scheduling on both the couple and the clinicians involved. In addition, assurance of the availability of male partner spermatozoa can be attained prior to beginning ovulation induction.

Objective: To evaluate the success of electroejaculation with assisted reproductive technologies (ART) in anejaculate men after retroperitoneal lymph node dissection (RPLND) for testicular cancer., Design: Retrospective clinical study., Setting: Tertiary care, university-affiliated IVF program., Patients: Anejaculate men after RPLND, spouses., Interventions: Electroejaculation, microsurgical sperm aspiration, various assisted reproductive technologies., Main Outcome Measures: Sperm density and motility, fertilization rate, pregnancy rate (PR)., Results: Compared with patients not receiving chemotherapy, patients who received chemotherapy had diminished average sperm densities and motilities (63 x 10(6) and 20% versus 101 x 10(6) 32%, respectively); decreased fertilization rates per cycle for IVF and intracytoplasmic sperm injection (ICSI) (11% versus 26%, respectively); lower PRs per cycle of hMG-IUI and IVF (14% versus 60% and 8% versus 50%, respectively). No pregnancies were achieved with natural cycle-IUI, clomiphene citrate-IUI, or GIFT. Two couples progressed to intracytoplasmic sperm injection with one achieving the successful delivery of healthy twins. The overall PR per cycle was 22%., Conclusions: Patients receiving chemotherapy had decreased sperm densities, motilities, fertilization, and PRs for each modality used. Rectal probe electroejaculation with ART can help anejaculate men after RPLND achieve biologic paternity. An early move to the more aggressive therapies (hMG-IUI, IVF, ICSI) is supported.

These three cases exemplify, in increasing order of complexity, how the common sense application of already successful techniques might be applied to augment the chance of pregnancy in this group of patients. We believe this to be the first report specifically outlining measures that may assist this group in their goal of pregnancy achievement. To our knowledge, vasal sperm aspiration has never been used for this indication.