Search

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.

Klinefelter syndrome (KS) is a common disorder and almost every clinician in almost every sub-specialty of medicine will knowingly or unwittingly treat boys or men with a 47,XXY chromosomal constitution. Although there are numerous aspects of KS worthy of discussion, this contribution will focus specifically on the controversial, and as yet unresolved, issue of whether it is advantageous to harvest testis tissue from peri-pubertal or adolescent boys with KS in a heroic effort to preserve that child's chances of reproduction in his future adult life. What would be the rationale for that, how does the biology of spermatogenesis in the Klinefelter testis impact that decision, and what does the data show? The answer, assembled from a selection of seemingly disparate sources and directions, appears to be "No". We do not have to advocate for an aggressive approach, we do not have to preemptively preserve future fertility. We can justifiably wait until adulthood with equivalent chances of success.

Hormonal and surgical treatments for transgender individuals can severely impact reproductive potential. In this review, we discuss the role of fertility preservation in both male-to-female and female-to-male transgender patients. We focus on the effects of hormone replacement therapy on the gonads and discuss current methods and techniques available for fertility preservation. Moreover, we review the current literature on patient attitudes toward fertility preservation and existing barriers to care. The literature supports the notion that feminizing therapy negatively impacts spermatogenesis, as evidenced by impaired semen parameters. The degree of such decline lies on a spectrum and can be somewhat unpredictable. Similarly, masculinizing therapy with testosterone has variable effects on ovarian function, gynecologic organs, and future fertility potential. Further research is required to better elucidate the long-term effects of such therapies. Optimal timing for fertility preservation is in the postpubertal period prior to initiation of hormonal therapy. This is however not always possible. A multitude of barriers to pursuing fertility preservation exist, including lack of appropriate counseling, the potentially invasive nature of some fertility preservation methods, and the financial burden placed on the patients. Fertility preservation in the transgender population remains poorly utilized. For transgender women, cryopreservation of sperm ideally is performed prior to initiation of hormone replacement therapy. Nonetheless, studies have shown that a degree of spermatogenesis is seen in some individuals without discontinuation of hormonal therapy. This could allow for less disruption, both physically and emotionally. Fertility preservation in transgender men remains invasive with oocyte retrieval as the main technique. Cessation of therapy, ovarian stimulation, and invasive testing has potential to be traumatic and enhance dysphoria. The possibility of fertility preservation at the time of gonadectomy is promising. Prepubertal fertility preservation is also on the horizon, though still experimental. Cost of preservation techniques and storage is currently prohibitive for many patients. Recent changes to state insurance mandates may soon make fertility preservation more accessible. Future research may demonstrate that fertility preservation is possible at the time of gender confirmation surgery, with the goal of being both effective and nontraumatic to the patient.

Azoospermia describes up to 20% of males who are evaluated for infertility. While a small fraction of these cases can be explained by obstructive causes, the remainder will be due to factors intrinsic to the testis, such as spermatogenic dysfunction (Tournaye et al., 2017 [39] ). In a subset of these patients, chromosomal and genetic anomalies will be identified. Klinefelter syndrome (KS; 47, XXY) is the most common genetic etiology of male infertility and almost universally leads to nonobstructive azoospermia [43]. For example, in a large cohort of 388 azoospermic men, KS was detected in 14.7%, which is in line with prior incidence figures (Punab et al., 2017 [29] ). Although less prevalent, Y chromosome microdeletions have been well studied and known to quantitatively affect spermatogenesis. The various types of microdeletions and their clinical consequences are described in the second half of this contribution.

Progress has been made in determining the fertility timeline and potential in adolescents with Klinefelter syndrome; however, medical professionals are currently without protocols to guide treatment.To evaluate the current practices regarding fertility and andrology care in adolescent males with Klinefelter syndrome.A 24-question survey was developed to elicit practitioner background/expertise and management practices. This was distributed to members of the Society for the Study of Male Reproduction, the Pediatric Endocrine Society, and the Endocrine Society.N/A.Adolescent males with Klinefelter syndrome.None.Current practices regarding fertility and andrology care.232 responses were received from 133 (57%) adult endocrinologists, 60 (26%) pediatric endocrinologists, and 39 (17%) urologists. Among these, 69% of respondents were in academics, 62% practiced for10 years, and 65% received formal training in Klinefelter syndrome. All specialties encouraged sperm banking in late puberty, however most disagreed with the practice in early puberty. Seventy-eight percent agreed that testicular biopsy should be offered if no sperm was found in the ejaculate. The perceived optimal age for testicular biopsy varied among specialists. Clinical symptoms of hypogonadism (28%), rising gonadotropin levels (15%), and testosterone levels (15%) were the most commonly cited reasons for initiation of testosterone replacement therapy.Fertility preservation practices in adolescents with Klinefelter syndrome vary greatly within and among the specialties caring for these patients. These findings should guide future research and highlight the importance of establishing clinical practice guidelines.

Summary An accurate medical history and directed physical examination are essential in diagnosis of male infertility. We review the hormonal assessments and specific genetic analyses that are useful additional tests, and detail other evidence-based examinations that are available to help guide therapeutic strategies. By contrast with female infertility treatments—especially hormonal manipulations to stimulate or enhance oocyte production—spermatogenesis and sperm quality abnormalities are much more difficult to affect positively. In general, a healthy lifestyle can improve sperm quality. A few men have conditions in which evidence-based therapies can increase their chances for natural conception. In this second of two papers in The Lancet Diabetes and Endocrinology Series on male reproductive impairment, we examine the agreements and controversies that surround several of these conditions. When we are not able to cure, correct, or mitigate the cause of conditions such as severe oligozoospermia, non-remedial ductal obstruction, and absence of sperm fertilising ability, assisted reproductive technologies, such as in-vitro fertilisation (IVF) with intracytoplasmic sperm injection (ICSI), can be used as an adjunctive measure to allow for biological paternity. Not considered possible just two decades ago, azoospermia due to testicular failure, including 47,XXY (Klinefelter syndrome), is now treatable in approximately 50% of cases when combining surgical harvesting of testicular sperm and ICSI. Although genetic fatherhood is now possible for many men previously considered sterile, it is crucial to discover and abrogate causes as best possible, provide reliable and evidenced-based therapy, consider seriously the health and wellness of any offspring conceived, and always view infertility as a possible symptom of a more general or constitutional disease.

Summary Infertility is a widespread problem and a male contribution is involved in 20–70% of affected couples. As a man's fertility relies on the quantity and quality of his sperm, semen analysis is generally used as the proxy to estimate fertility or gain insight into the underlying reasons for infertility. Male reproductive impairment might result from factors that affect sperm production, quality, function, or transport. Although in most men the origin of infertility remains unexplained, genetic causes are increasingly being discovered. In this first of two papers in The Lancet Diabetes and Endocrinology Series on male reproductive impairment, we propose a novel, clinically based aetiological construct with a genetic focus, and consider how this might serve as a helpful way to conceptualise a diagnostic algorithm.

Cystic fibrosis transmembrane conductance regulator (CFTR) and adhesion G protein-coupled receptor G2 (ADGRG2) have been identified as the main pathogenic genes in congenital bilateral absence of the vas deferens (CBAVD), which is an important cause of obstructive azoospermia. This study aimed to identify the disease-causing gene in two brothers with CBAVD from a Chinese consanguineous family and reveal the intracytoplasmic sperm injection (ICSI) outcomes in these patients.Whole-exome sequencing and Sanger sequencing were used to identify the candidate pathogenic genes. Real-time polymerase chain reaction, immunohistochemistry, and immunofluorescence were used to assess the expression of the mutant gene. Moreover, the ICSI results from both patients were retrospectively reviewed.A novel hemizygous loss-of-function mutation (c.G118T: p.Glu40*) in ADGRG2 was identified in both patients with CBAVD. This mutation is absent from the human genome databases and causes an early translational termination in the third exon of ADGRG2. Expression analyses showed that both the ADGRG2 mRNA and the corresponding protein were undetectable in the proximal epididymal tissue of ADGRG2-mutated patients. ADGRG2 expression was restricted to the apical membranes of non-ciliated epithelia in human efferent ducts, which was consistent with a previous report in mice. Both ADGRG2-mutated patients had normal spermatogenesis and had successful clinical outcomes following ICSI.Our study verifies the pathogenic role of ADGRG2 in X-linked CBAVD and broadens the spectrum of ADGRG2 mutations. In addition, we found positive ICSI outcomes in the two ADGRG2-mutated CBAVD patients.

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.

Klinefelter syndrome can present as a wide spectrum of clinical manifestations at various stages in life, making it a chromosomal disorder with no standardized set of guidelines for appropriate management. Understanding the genetic and hormonal causes of this syndrome can allow physicians to treat each patient on a more individualized basis. The timing of diagnosis and degree of symptoms can guide management. This report will provide an updated review of the clinical presentation at various stages in life and the implications for management.

In about one-half of adult Klinefelter syndrome (KS) patients, spermatozoa can be retrieved by means of testicular biopsy (TESE). Given the expected increase in the number of diagnosed KS patients owing to the use of noninvasive prenatal testing, the probable questions of young KS patients and their parents regarding future fertility, and the fact that widespread apoptosis of spermatogonia occurs at onset of puberty, an attempt to increase the retrieval rates at TESE above those found in adult KS men by undertaking preservation techniques peripubertally has been initiated. To date, however, only a limited number of KS adolescents have been examined, demonstrating no increases in the chances of finding sperm. Furthermore, spermatogonial stem cell and testicular tissue freezing techniques, as well as in vitro maturation strategies, require further validation. Given these controversies, banking testicular tissue from prepubertal KS boys should be performed only in a research framework.

Primary ciliary dyskinesia is a group of disorders based upon structural and functional defects in the hair-like projections that are on many embryonic, fetal, and adult cells. As such, the respiratory and sinus systems are severely affected and typically lead to clinical diagnosis. Male fertility is often completely compromised as the motility of the sperm, necessary for the sperm to travel to and penetrate the egg, is absent or significantly deficient. Newer therapies, however, can help male patients achieve biological paternity. The genetic basis is varied and is becoming more clear with continued research.

Many disorders that affect the male reproductive axis, all way from sperm production to the sperm's ability to contribute to fertilization and normal embryo development are being investigated in an effort to understand the genetic or epigenetic basis. This knowledge is critical for both clinicians and the couples prior to proceeding along a pathway to parenthood using combinations of advanced reproductive techniques. Often, the other aspects of the male's health are at issue as well, the resultant infertility being just one aspect of a more global genetic health effect. Finally, offspring health is an important consideration as many disorders may now be transmitted to subsequent generations as we are able to overcome the infertility that nature was not able to.

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.

Congenital bilateral absence of the vas deferens (CBAVD) is a clinical condition that typically presents at the time of an evaluation for infertility. Most cases are caused by mutations in both parental cystic fibrosis gene alleles. Some cases are caused by defects in the development of the mesonephric ducts during embryogenesis that may result in associated renal agenesis. Proper genetic screening is mandatory. Sperm can be successfully harvested in a number of different ways and used with great efficacy to generate pregnancies and healthy offspring.

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-a-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.

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.

It is currently unclear whether an adolescent with 47,XXY Klinefelter syndrome will be better off having testicular sperm extraction (TESE) performed in an effort to ‘preserve fertility’ for the future or, alternatively, should be advised to simply wait until adulthood when he and his partner are ready to begin a family. This report will provide data suggesting that there is no obvious ‘preservation’ benefit and that recommending TESE to the 47,XXY boy and his parents may not be as helpful as it might appear and may be overly aggressive.

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

Once thought to be a chromosomal aberration associated with absolute sterility, Klinefelter syndrome may now be potentially treatable by testicular sperm retrieval coupled with intracytoplasmic sperm injection. With these therapeutic advances, azoospermic 47,XXY men now may have an opportunity for biological paternity. However, our knowledge of the basic mechanisms underlying germ cell loss and Leydig cell compromise is lagging, and is just now beginning to evolve and provide answers to some of the field's most vexing questions: how to maximize and preserve fertility in Klinefelter males many years or even decades before they wish to actively pursue fatherhood. This article reviews the development of the androgenic and spermatogenic compartments of the Klinefelter testis through puberty, and recommends that it is only with a clear understanding of the basic facts that a rational, considered approach to fertility optimization and preservation can be determined.

Purpose of review Therapies for the treatment of severe male factor infertility have advanced well beyond our knowledge of the conditions we are treating. An intact Y chromosome is necessary for optimal spermatogenesis. It is imperative for the clinician to understand the molecular basis and clinical implications of anomalies that might afflict the Y chromosome. Recent findings The molecular geography of the Y chromosome has recently been described, allowing correlations to be made to various clinical states of severe spermatogenic compromise. Microdeletions of parts of the Y chromosome are found in a small number of men with spermatogenic failure involving, predominantly, three regions termed AZFa, AZFb, and AZFc. Summary It is necessary that a Y chromosomal microdeletion assay be carried out prior to any intervention using ejaculated sperm or prior to any surgical procedure to try to find spermatozoa in an azoospermic man.

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., Howard Hughes Medical Institute (Award), National Institutes of Health (U.S.) (NIH/NIGMS grant R01GM076327)

What do we know about the genetic causes of reproductive failure in men who are otherwise healthy? What is the rationale for testing? What therapeutic and counseling interventions are most appropriate, based on the genetic diagnoses? Research and clinical experience are beginning to provide some answers.

To the Editor: We read with interest the report of a novel deletion of part of the azoospermia factor c (AZFc [MIM 415000]) region of the human Y chromosome (Fernandes et al. 2004). This article reported that the deletion is found only in branch N of the Y-chromosome genealogical tree, occurs through one mutational pathway, is ∼2.2 Mb in size, and has no effect on spermatogenesis. We, too, recently reported this deletion, which Fernandes et al. termed the “g1/g3” deletion and which we termed the “b2/b3” deletion (Repping et al. 2004). Our findings, however, differed from those of Fernandes et al. in several important particulars: (1) our screening of 1,563 men demonstrated that this deletion is not confined to branch N and that it has at least four independent origins; (2) our analysis revealed two mutational pathways, rather than one, that can generate the deletion, and we confirmed the existence of the inverted AZFc organizations that are the intermediate steps in these pathways; (3) on the basis of the reference sequence of the Y chromosome, we concluded that the size of the deletion is 1.8 Mb, rather than ∼2.2 Mb; (4) using interphase FISH, we confirmed the amplicon organization that was postulated in the deletion and also identified three instances of duplication subsequent to the deletion; and (5) because of the possibility of a compensatory factor on Y chromosomes in branch N and because of the limited number of deletions outside this branch, we concluded that a possible effect of this deletion on risk of spermatogenic failure cannot be excluded (Repping et al. 2004). Beyond these differences, however, the characterizations of this and other partial deletions of AZFc (Repping et al. 2003) highlight a more important question. At issue is the relative utility of sequence family variants (Saxena et al. 2000), compared with that of plus/minus STSs, for identification and differentiation of deletions involving AZFc. AZFc is composed entirely of amplicons—repeat units 115–678 kb in length that only differ by ∼1 nt per 3,000 bp. These rare differences are called “sequence family variants” (SFVs). We previously relied on SFVs to map and sequence the AZFc region of one man’s Y chromosome (Kuroda-Kawaguchi et al. 2001). The report by Fernandes et al. (2004) emphasized the use of SFVs in identification of the novel deletion, whereas our analysis relied on plus/minus STSs for identification of the deletion, followed, in most instances, by confirmation with FISH. Two observations led us to ask whether SFVs, as opposed to plus/minus STSs, offer the simpler and more robust means of detecting and distinguishing deletions in AZFc. First, figures 1 and 4 in the report by Fernandes et al. (2004) indicated that negative results at the plus/minus STS sY1192 or 50f2/C combined with positive results at flanking STSs are sufficient to detect the deletion (table 1). Moreover, the b2/b3 deletion and other types of deletions involving AZFc can be distinguished by their plus/minus signatures, without the use of SFVs (table 1). Table 1 Plus/Minus STS Results Distinguishing Different Types of Deletions Involving AZFc[Note] Second, table 2 in the report by Fernandes et al. (2004) showed that the SFV patterns of undeleted chromosomes vary considerably among different branches of the Y-chromosome genealogy and that the patterns also vary among individuals within branches. These observations suggested that the link between SFV patterns and particular types of deletions would likely not be consistent across the worldwide diversity of Y chromosomes. The diversity of SFV patterns in undeleted chromosomes is not surprising, since AZFc is subject to large inversions, deletions, and duplications caused by ectopic homologous recombination between amplicons (Kuroda-Kawaguchi et al. 2001; Repping et al. 2003, 2004). Such events would rearrange the locations of particular variants and would blur the association between SFV patterns and particular types of deletions. The association would likely be further blurred by gene conversion, which frequently erases small sequence differences (i.e., SFVs) between amplicon copies on the Y chromosome (Rozen et al. 2003). We experimentally investigated the consistency of SFV patterns in different types of deletions involving AZFc. First, using the SFVs employed by Fernandes et al. (2004), we typed 20 men reported elsewhere to have the b2/b3 deletion (Repping et al. 2004) (see GenBank Web site for SFV assays). These men represented branch N and three other branches of the Y-chromosome genealogy (fig. 1). Second, using the same SFVs, we typed 40 men reported elsewhere to have the gr/gr deletion, the other common partial AZFc deletion (Repping et al. 2003). These men represented 14 branches of the Y-chromosome genealogy (fig. 1). Figure 1 Genealogical analysis of SFV patterns associated with b2/b3 and gr/gr deletions. In the SFV patterns, “C” indicates the cut variant described by Fernandes et al. (2004), “U” indicates the uncut variant, “B” ... The b2/b3 deletions outside branch N showed diverse SFV patterns, and the gr/gr deletions showed even greater diversity (fig. 1). This greater diversity was likely due to the larger number of independent gr/gr deletions studied. Two branches, F*(xHK) and R1*x, contained numerous deletions and a high diversity of SFV patterns (fig. 1). In these branches, multiple independent deletion events probably account for the high diversity. By contrast, two other branches, D2b and N, contained numerous deletions but uniform SFV patterns. This uniformity is explained by the fact that all chromosomes in these branches descended from deleted founders (Repping et al. 2003, 2004; Fernandes et al. 2004). Thus, the chromosomes in each of these branches represent a single deletion event. Our data also showed that the SFV patterns of b2/b3 and gr/gr deletions are not distinct from each other. For example, the b2/b3 pattern UUUCUU−CUUU (branch F*[xHK]) is more similar to the gr/gr pattern UUCCUU+CBUB (branch F*[xHK], four differences [underlined]) than to the b2/b3 pattern UBBBCU−CCUC (branch N, six differences). In another example, the gr/gr pattern UBBBCU−UBUB (branch R1*x) is more similar to the b2/b3 pattern UBBBCU−CUUC (branch I, three differences) than to the gr/gr pattern BCCCUB+CBCC (branch R1*x, 10 differences). In conclusion, the SFV patterns of b2/b3 and gr/gr deletions vary widely and are not clearly distinct. SFVs can offer insight only if one knows the common SFV organizations in the genealogical branches represented by the Y chromosomes being tested. However, SFV organizations across the Y-chromosome genealogical tree are largely unknown, and SFV patterns vary even among individuals in the same branch. Just as important is that a large number of two-step assays are needed for SFV typing and for determining the Y-chromosome branch. By contrast, six simple plus/minus STSs distinguish between the deletions involving AZFc (table 1). Thus, plus/minus STSs provide a straightforward means of identifying and distinguishing the deletions of part of AZFc, whereas, in most situations, SFVs do not.

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. (C) 2004 Elsevier Inc. All rights reserved

Summary OBJECTIVE The most frequent known genetic causes of severe oligospermia (< 5 million sperm/ml) or azoospermia in men are Klinefelter’s syndrome (KS), and deletions in the Y chromosome long arm (Yq). We aimed to compare the function of the pituitary‐ testicular axis in patients with severe oligospermia or azoospermia, idiopathic or associated with Y chromosome deletions or Klinefelter’s syndrome (KS) and in control subjects. PATIENTS We studied 47 men with idiopathic oligoazoospermia, 42 with Yq deletions (27 AZFc, 13 AZFb and two AZFa) and oligo-azoospermia, 14 with KS and 39 control subjects (total 143). MEASUREMENTS We analysed levels of FSH, inhibinB, LH, free testosterone and oestradiol in all subjects, and we calculated indexes based on those hormones. RESULTS Inhibin-B levels were indistinguishable between patients with idiopathic and Y deletion-associated oligo-azoospermia, lowest in the Klinefelter’s patients and highest in controls. FSH levels followed the reverse pattern: indistinguishable between patients with idiopathic and deletion-associated oligoazoospermia, highest in Klinefelter’s patients and lowest in controls. Oestradiol, free testosterone and the derived indeces were not different in subjects with Yq deletions compared to those with idiopathic oligo-azoospermia. Among the Yq-deleted patients, no measured or derived parameter differed between the subjects with AZFc deletion and those with AZFb deletion. When non-KS oligo-azoospermic patients were classified according to histology [Sertoli cell-only (SCO), n = 18 or non-Sertoli cell only (non-SCO), n = 18] and compared to KS patients, the hormonal pattern did not differ between SCO and non-SCO subjects, but levels in KS patients were significantly different for FSH, inhibin-B and the FSH/inhibin-B ratio. KS patients not only had lower inhibin-B than SCO and non-SCO oligo-azoospermic men, but also higher FSH levels for any given inhibin-B concentration. CONCLUSION Our data show that Y-deleted patients do not have a lesser impairment of Sertoli cell function than patients with idiopathic oligo-azoospermia, and support the concept that the main determinant of inhibin-B production is the germ cell mass. Also, our results suggest that one or more other factors, apart from inhibin-B, may contribute to increased pituitary secretion of FSH in KS patients.

Many human Y-chromosomal deletions are thought to severely impair reproductive fitness, which precludes their transmission to the next generation and thus ensures their rarity in the population. Here we report a 1.6-Mb deletion that persists over generations and is sufficiently common to be considered a polymorphism. We hypothesized that this deletion might affect spermatogenesis because it removes almost half of the Y chromosome's AZFc region, a gene-rich segment that is critical for sperm production(1,2). An association study established that this deletion, called gr/gr, is a significant risk factor for spermatogenic failure. The gr/gr deletion has far lower penetrance with respect to spermatogenic failure than previously characterized Y-chromosomal deletions; it is often transmitted from father to son. By studying the distribution of gr/gr-deleted chromosomes across the branches of the Y chromosome's genealogical tree, we determined that this deletion arose independently at least 14 times in human history. We suggest that the existence of this deletion as a polymorphism reflects a balance between haploid selection, which culls gr/gr-deleted Y chromosomes from the population, and homologous recombination, which continues to generate new gr/gr deletions

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.

Deletions of the AZFc (azoospermia factor c) region of the Y chromosome are the most common known cause of spermatogenic failure. We determined the complete nucleotide sequence of AZFc by identifying and distinguishing between near-identical amplicons (massive repeat units) using an iterative mapping-sequencing process. A complex of three palindromes, the largest spanning 3 Mb with 99.97% identity between its arms, encompasses the AZFc region. The palindromes are constructed from six distinct families of amplicons, with unit lengths of 115-678 kb, and may have resulted from tandem duplication and inversion during primate evolution. The palindromic complex contains 11 families of transcription units, all expressed in testis. Deletions of AZFc that cause infertility are remarkably uniform, spanning a 3.5-Mb segment and bounded by 229-kb direct repeats that probably served as substrates for homologous recombination.

Objective: To determine the presence or absence of the deleted in azoospermia ( DAZ ) gene clusters in the Y-bearing spermatozoa in semen of severely oligozoospermic men or in testicular biopsy samples of azoospermic men with somatic DAZ deletions. Design: Prospective study. Setting: Academic hospital. Patient(s): Nineteen patients attending our clinics for therapeutic intracytoplasmic injection of sperm. Intervention(s): Peripheral blood lymphocytes were used to obtain somatic DNA for analysis using the polymerase chain reaction. Analysis of chromosomes X and Y and the detection of the DAZ gene clusters were carried out with the fluorescence in situ hybridization technique in spermatozoa remaining after intracytoplasmic sperm injection. Main Outcome Measure(s): Presence or absence of the DAZ gene clusters in matched somatic DNA and Y-bearing spermatozoa. Result(s): Seven patients appeared to have a somatic DAZ deletion. Three-color fluorescence in situ hybridization showed that all Y-bearing spermatozoa examined from these men carried the same deletion. Conclusion(s): The DAZ deletions present in the seven men would all have been transmitted if they had fathered sons through artificial fertilization techniques using the sperm cells examined in this study.

An association between congenital bilateral absence of the vas deferens (CBAVD), normal renal anatomy and cystic fibrosis (CF) gene mutations is well established (CF/CBAVD). We postulate that unilateral renal agenesis (URA) and CBAVD (URA/CBAVD) may have a non-CF mutation-mediated genetic basis that leads to abnormal development of the entire mesonephric duct at a very early stage in embryo development (< or =7 weeks). The physical, laboratory and radiographic findings of men with URA/CBAVD (n = 17) and CF/CBAVD (n = 97) were compared; the fertilization and pregnancy rates in the URA/CBAVD population calculated, and the incidence of renal agenesis in immediate family members and offspring of men with URA/CBAVD analysed. No statistical differences could be identified within any of the above comparisons. The fertilization rate for the URA/CBAVD group was 58.2 +/- 26.3%. Eight infants and two fetuses had normal renal anatomy, while one terminated male fetus had bilateral renal and vasal agenesis. Thirty first-order relatives had normal renal units. Anatomical expression of the reproductive ductal derivatives in men with URA/CBAVD and CF/CBAVD was similar, but the phenotypic outcome of the renal portion of the mesonephric duct was different. The potential for transmission of this fatal anomaly reinforces the need for prenatal ultrasounds with all pregnancies involving URA/CBAVD men.

Background: Men with cystic fibrosis (CF) havebilateral absence of the vas deferens causing an obstructiveazoospermia that is not amenable to surgical correction. Advances inthe field of reproductive medicine allow for the procurement of viablesperm and facilitate fertilization and pregnancy in couples where theman has CF. Objectives: To describe patient anatomyand semen characteristics and to determine the pregnancy rates of couples in whom the male partner has CF and who have undergonemicrosurgical epididymal sperm aspiration coupled with invitro technology, specifically intracytoplasmic sperm injection(ICSI). Design: Retrospective analysis. Setting: Clinical department of urology and tworeproductive medicine units. Patients: Thirteenmarried men with CF who were referred for infertility. Interventions: History, physical examination, semenanalysis, transrectal and renal ultrasonography, CF mutation analysis, and microsurgical sperm aspiration coupled with ICSI. Results: All 13 men had low-volume azoospermia, absentvasa, and aplasia/hypoplasia of the seminal vesicles. CF mutationanalysis was carried out in 11 of 13 men, and 9 of 11 were ΔF508homozygous. Eight men underwent microsurgical sperm aspiration, andtheir partners underwent one or more cycles of ICSI. Five couples(62.5%) achieved a pregnancy, with four couples delivering (three setsof twins and one singleton). Conclusions: CF in men isaccompanied by bilateral vasal aplasia. The resultant obstructiveazoospermia can be treated quite successfully with a combination of sperm aspiration and ICSI. It is important for physicians involved inthe care of men with CF to convey the message that prospects forfatherhood are excellent with current technology.

Deletion of any of three regions of the human Y chromosome results in spermatogenic failure and infertility. We previously sequenced one of these regions, azoospermia factor a (AZFa) and found that it spanned approximately 800 kb. By sequence-tagged site (STS) content mapping, we roughly defined deletion breakpoints in two unrelated, azoospermic men with AZFa deletions. The positions of proximal and distal breakpoints were similar in the two men. Hypothesizing that the deletions might have been generated by homologous recombination, we searched electronically for DNA sequence similarities between the proximal and distal breakpoint regions. These comparisons revealed the most striking sequence similarities anywhere along or near the AZFa region. In the proximal breakpoint region, we identified a 10 kb provirus of the recently defined HERV15 class of endogenous retroviruses. In the distal breakpoint region, we found a second HERV15 provirus, 94% identical in DNA sequence to the first and in the same orientation. (A partial LINE insertion in this distal provirus proved to be the basis of the previously described DYS11/p12f polymorphism.) The AZFa deletions in the two men differed slightly, but all breakpoints fell within the HERV15 proviruses. Indeed, sequencing of deletion junctions from the two men revealed that homologous recombination had occurred within large domains of absolute sequence identity between the proximal and distal proviruses. When combined with published STS mapping data for other AZFa-deleted men, our findings suggest that recombination between these two HERV15 proviruses could account for most AZFa deletions.

In humans, deletion of any one of three Y-chromosomal regions—AZFa, AZFb or AZFc—disrupts spermatogenesis, causing infertility in otherwise healthy men1,2,3,4,5. Although candidate genes have been identified in all three regions3,6,7,8, no case of spermatogenic failure has been traced to a point mutation in a Y-linked gene, or to a deletion of a single Y-linked gene. We sequenced the AZFa region of the Y chromosome and identified two functional genes previously described: USP9Y (also known as DFFRY) and DBY (refs 7,8). Screening of the two genes in 576 infertile and 96 fertile men revealed several sequence variants, most of which appear to be heritable and of little functional consequence. We found one de novo mutation in USP9Y: a 4-bp deletion in a splice-donor site, causing an exon to be skipped and protein truncation. This mutation was present in a man with nonobstructive azoospermia (that is, no sperm was detected in semen), but absent in his fertile brother, suggesting that the USP9Y mutation caused spermatogenic failure. We also identified a single-gene deletion associated with spermatogenic failure, again involving USP9Y, by re-analysing a published study.

Objectives Hitherto, patients with testicular dysfunction and azoospermia had to resort to adoption, donor sperm insemination, or child-free living. The realization that a proportion of such men harbor spermatozoa in their testicular parenchyma, combined with the ability of intracytoplasmic sperm injection (ICSI) to effect pregnancy with single sperm, has prompted male infertility clinicians to explore testicular sperm extraction (TESE) in this patient population. We sought to investigate the likelihood of finding spermatozoa during TESE from men presenting with nonobstructive azoospermia and to define if any factors existed that were predictive of eventual sperm presence or absence. Methods Thirty patients with nonobstructive azoospermia underwent TESE and simultaneous formal testis biopsy, cytologic analysis, and wet preparation analysis. Tissue obtained from TESE was analyzed according to a rigorous protocol, followed by exhaustive searching by trained embryologists. Results Twenty-one patients (70%) had spermatozoa found on testicular tissue analysis. Neither patient age nor follicle-stimulating hormone (FSH) level was predictive of the ability to find sperm. With regard to histologic pattern, 50% of men with Sertoli cell-only, 75% of patients with maturation arrest, and 100% of patients with spermatids seen on histologic analysis had sperm retrieved from their testicular tissue during TESE. Absence of sperm on cytologic smear and wet preparation analysis failed to predict the presence of sperm on formal testicular tissue analysis in 40% of patients. Conclusions Men with nonobstructive azoospermia may have mature spermatozoa present within their testicular parenchyma. Relying on these data, patients should not be excluded from TESE based on serum FSH level, age, prior histopathologic pattern, or cytology/wet preparation results. These figures will allow clinicians to counsel patients with nonobstructive azoospermia informatively regarding TESE and their chances of having testicular sperm retrieved.

Ejaculatory dysfunction may occur after many different disorders ranging from traumatic spinal cord injury to diabetes mellitus. With an understanding of the many facets and nuances of the ejaculatory apparatus, both anatomic and neurologic, the well-versed clinician can proceed along a safe, efficient, and appropriate treatment algorithm to help affected men and their partners achieve parenthood.

Men with cancer rendered infertile by surgery, chemotherapy, radiation and hormone therapy that are needed to control or cure their disease are increasingly being offered the chance to preserve their reproductive potential through artificial reproductive technologies. Cryopreservation of sperm and testicular tissue have increasingly helped boys and men preserve their fertility. There is a growing subspecialty within reproductive medicine aimed at fertility preservation in this population. Furthermore, strategies are being developed that may in the future revolutionize the approach to such patients. Written by international authorities in the field of fertility preservation, this comprehensive book is aimed at clinicians dealing with male cancer patients, in particular, urologists, andrologists, oncologists, pediatricians and nursing staff as well as clinicians in reproductive endocrinology. The text reviews the impact of cancers and their treatment on male fertility, the available fertility preservation strategies and post-treatment management.

Quantitative deficiencies in spermatogenesis, aberrations in spermatozoal ultramorphology, or defects in spermatozoal nuclear/DNA health may lead to male factor infertility. Rare situations present themselves when the clinical question of whether to harvest testis sperm, even when ejaculate sperm are available, arises. This chapter will try to provide an answer to this vexing problem by positing several scenarios and looking at the literature that bears on each: (1) Is testis sperm as genetically safe and competent as ejaculated sperm and vice versa when used as the sperm source for intracytoplasmic sperm injection? (2) Is testis sperm the answer when there are gross morphological abnormalities seen in the ejaculate sperm? (3) Is testis sperm the answer when there is extremely limited motility in the ejaculate sperm? (4) Is testis sperm the answer when there is increased DNA fragmentation in the ejaculate sperm or repeated ICSI failure for unknown reasons?

Congenital bilateral absence of the vas deferens (CBAVD) was once thought to be a distinct clinical entity, but genetic similarities in men with cystic fibrosis (CF) and CBAVD are described increasingly. We evaluated the clinical status, growth and nutritional state, and respiratory function of 18 men with CBAVD to determine whether these men with different CF transmembrane regulator (CFTR) genotypes may have clinical evidence of mild CF. Following a thorough history and examination, pulmonary function tests, sweat test, and renal ultrasound were performed. Genetic evaluation for 50 known CF mutations, screening for private mutations (single-strand conformational polymorphism and direct sequencing), and assay of the length of the polypyrimidine tract in the splice site acceptor of intron 8 was performed. A history of pulmonary disease was present in three, and an additional man had some features suggestive of malabsorption. Results of general physical examination and anthropomorphic measurements were unremarkable in all patients, with a mean (SD) body mass index of 26 (3). Pulmonary function tests of large and small airway function as well as lung volumes were normal in all except one whose results were consistent with moderate asthma. Five men were compound heterozygotes for CFTR mutations, four of whom had positive sweat tests (sweat chloride >60 mEq/L). Twelve men were heterozygotes for CFTR mutations while no mutations were identified in one man. Although putative etiologic factors may suggest that men with CBAVD and CFTR mutations could be considered within the spectrum of clinical CF, the authors suggest that in men with CBAVD without any other clinical features of CF, the diagnosis of CF may not be made.

The conception rate of patients with spinal cord injuries following penile vibratory stimulation and rectal probe electroejaculation in conjunction with self-insemination, intrauterine insemination or assisted reproductive technique is poorly documented. We reviewed our success rates with penile vibratory stimulation and rectal probe electroejaculation, and the pregnancy rates achieved with self-insemination, intrauterine insemination and assisted reproductive techniques.A total of 78 consecutive patients with spinal cord injuries had a complete neurological examination and was treated initially with penile vibratory stimulation. If unsuccessful, rectal probe electroejaculation was performed to obtain an ejaculate. The ejaculate was then used with self-insemination, intrauterine insemination or assisted reproductive techniques and pregnancies were monitored.Vibratory stimulation was successful in 20 of 37 patients (54%) with a cervical lesion, 14 of 26 (54%) with a lesion at or above T10 and none of 15 when the lesion was below T10. All patients except 2 who elected followup rectal probe electroejaculation had antegrade or retrograde ejaculate. Six patients (7.7%) with extremely poor semen quality were not candidates for assisted fertilization. Of 27 couples who attempted conception 17 were successful (5 self-insemination, 5 intrauterine insemination and 7 assisted reproductive techniques).Penile vibratory stimulation should be used as first line therapy in patients with lesions above T10 while rectal probe electroejaculation should be considered as a second option. Motivated patients can achieve success with self-insemination, intrauterine insemination and assisted reproductive techniques.

A total of 21 infertile men with congenital unilateral absence of the vas deferens (CUAVD) were studied to determine if this disorder involves mutations in the cystic fibrosis (CF) gene. This hypothesis derives from previous work which has established the genetic commonality of CF and congenital bilateral absence of the vas deferens (CBAVD). Both CF and CBAVD may result from compound heterozygosity for CF mutations. In our patients with unilateral vasal aplasia, 12 had anatomically complete and patent vasa deferentia on the contralateral side, i.e. side of the scrotally palpable vas. No CF mutations were detected in this subgroup. The remaining nine patients had a non-iatrogenic occlusion of the contralateral vas at either the inguinal or pelvic level. In this subgroup, eight out of nine (89%) had a mutation detected in one of their two CF genes. This is the first study to define accurately the clinically and anatomically heterogeneous nature of CUAVD and to begin to clarify the genetic basis of unilateral absence of the vas deferens.

Assisted reproductive techniques have revolutionized the treatment of male reproductive failure, allowing biological fatherhood to be achieved by many men that nature would have never permitted. As we are able to help more and more couples with our therapies, the genetic basis of the man's spermatogenic, anatomical, or spermatozoal dysfunction needs to be determined so as to inform the couple whether there will be adverse consequences to either the patient individually or to any female or male offspring that may result. The goal of all that is done in reproductive medicine should include not just a singular thought process involving the couple and their desires to get pregnant but should take a wider view that encompasses the children we create and their physical, psychological, and genetic well-being. This article will review some of the more common or recognized conditions resulting in male reproductive failure, what is known or hypothesized about their genetic basis, and the adverse consequences that may arise for the patient or any offspring.