EAA/EMQN best practice guidelines for molecular diagnosis of Y-chromosomal microdeletions: state-of-the-art 2013

[AFU and SALF recommendations for the evaluation of male infertility]

BACKGROUND

The aim of these Association Française d'Urologie (AFU) and Société d'Andrologie de Langue Française (SALF) common recommendations are to provide practice guidelines for the French Urological and Andrological community regarding the evaluation of infertile men.

MATERIAL AND METHODS

Literature search in PubMed using the keywords "male infertility", "diagnosis", "management" and "evaluation" limited to clinical articles in English and French prior to 1/01/2020. To inform the level of evidence, the HAS grading system (2013) was applied.

RESULTS

Concerning the evaluation of infertile men, the AFU and the SALF recommend : (1) a systematic interview exploring the family history, the fertility history of the man outside the couple, the patient's personal history that may have an impact on his fertility, lifestyle habits, treatments, symptoms and possible sexual difficulties of the couple; (2) a general physical examination to assess signs of hypogonadism and secondary sexual characters; (3) a scrotal physical examination performed by an urologist or andrologist to assess (i) the testes for volume and consistency, (ii) vas deferens and epididymes for total or partial absence or nodules, and (iii) presence of varicoceles; (4) Performing two semen analyses, according to World Health Organization guidelines, if the first one has at least one abnormaly; (5) a scrotal ultrasound as part of routine investigation, that can be completed with an endorectal pelvic ultrasound according to the clinic; (6) an endocrine evaluation with at least a Testosterone and FSH serum determination; (7) Karyotype analysis in infertile men with a sperm concentration ≤10 10⁶/mL; (8) assessment of Yq microdeletions in infertile men with a sperm concentration ≤1 10⁶/mL; (9) Cystic fibrosis transmembrane conductance regulator gene evaluation in case of suspicion for bilateral or unilateral congenital agenesis of vas deferens and seminal vesicles. The interest of tests analyzing DNA fragmentation (TUNEL, SCSA) is still under investigation.

CONCLUSION

These guidelines can be applied in routine clinical practice in all infertile men.

Genetic mutations contributing to non-obstructive azoospermia

Non-obstructive azoospermia is a distinct diagnosis within male infertility in which no sperm is found in the ejaculate as a result of spermatogenesis failure. Because of the increased prevalence of genetic abnormalities in men with non-obstructive azoospermia, male infertility guidelines recommend screening for karyotype abnormalities and Y chromosome microdeletions in this population. Numerous karyotype abnormalities may be present resulting in impaired spermatogenesis, including: Klinefelter syndrome, translocations, and deletions. Y chromosome microdeletions of the AZFa, AZFb, AZFc subregions all can also result in non-obstructive azoospermia with the possibility of sperm being present if only the AZFc subregion is deleted. While these are the two genetic tests recommended by the guidelines, nearly 50%-80% of non-obstructive azoospermia has no identifiable cause and is deemed idiopathic. Several other genetic defects can lead to non-obstructive azoospermia including Kallmann syndrome, mild androgen insensitivity syndrome, and TEX11. While many additional candidate genes have been proposed, many have yet to be verified or are so infrequent in the population that screening is cost-ineffective. Much research is still required in the genetics of non-obstructive azoospermia and will require multi-institutional initiatives to better understand the genetics of condition.

Disruption of human meiotic telomere complex genes TERB1, TERB2 and MAJIN in men with non-obstructive azoospermia

Non-obstructive azoospermia (NOA), the lack of spermatozoa in semen due to impaired spermatogenesis affects nearly 1% of men. In about half of cases, an underlying cause for NOA cannot be identified. This study aimed to identify novel variants associated with idiopathic NOA. We identified a nonconsanguineous family in which multiple sons displayed the NOA phenotype. We performed whole-exome sequencing in three affected brothers with NOA, their two unaffected brothers and their father, and identified compound heterozygous frameshift variants (one novel and one extremely rare) in Telomere Repeat Binding Bouquet Formation Protein 2 (TERB2) that segregated perfectly with NOA. TERB2 interacts with TERB1 and Membrane Anchored Junction Protein (MAJIN) to form the tripartite meiotic telomere complex (MTC), which has been shown in mouse models to be necessary for the completion of meiosis and both male and female fertility. Given our novel findings of TERB2 variants in NOA men, along with the integral role of the three MTC proteins in spermatogenesis, we subsequently explored exome sequence data from 1495 NOA men to investigate the role of MTC gene variants in spermatogenic impairment. Remarkably, we identified two NOA patients with likely damaging rare homozygous stop and missense variants in TERB1 and one NOA patient with a rare homozygous missense variant in MAJIN. Available testis histology data from three of the NOA patients indicate germ cell maturation arrest, consistent with mouse phenotypes. These findings suggest that variants in MTC genes may be an important cause of NOA in both consanguineous and outbred populations.

The Male Is Significantly Implicated as the Cause of Unexplained Infertility

Male infertility is recognized as a relatively common, complex condition, generated by a broad array of environmental and genetic factors. Historical reliance on the conventional semen profile has tended to underestimate the true contribution of "the male factor" to human infertility. This review highlights the importance of genetic and epigenetic factors in the etiology of male infertility, identifying a range of mutations responsible for primary testicular failure and impaired fertilizing potential. More than three quarters of all de novo mutations arise in the male germline via mechanisms that involve the inefficient or defective repair of DNA damage. Understanding the range of factors capable of creating genetic turmoil in the paternal germline is essential, if we are to gain a deep understanding of the causes of male infertility, rather than just the symptoms that characterize its presence. High levels of DNA fragmentation induced by oxidative stress are part of this equation. Oxidative stress is, in turn, driven by biological (age, ejaculation frequency, varicocele, infection), lifestyle (smoking, obesity), and environmental factors (heat, other forms of electromagnetic radiation, and toxins) that can impair the fertilizing potential of the spermatozoa and influence the incidence of spontaneous mutations that may cause infertility in the offspring.

Predictive model to estimate the chances of successful sperm retrieval by testicular sperm aspiration in patients with nonobstructive azoospermia

OBJECTIVE

To explore predictors of successful sperm retrieval (SR) and to identify potentially suitable candidates for testicular sperm aspiration (TESA), a more straightforward, less traumatic, and less costly procedure than open surgical SR methods.

DESIGN

Retrospective chart review.

SETTING

Academic tertiary medical center.

PATIENTS

A total of 297 patients with nonobstructive azoospermia.

INTERVENTIONS

All patients underwent full clinical evaluation before undergoing a staged SR procedure, starting with TESA and proceeding to microsurgical testicular sperm extraction (microTESE). Predictors of positive SR with TESA were selected using the least absolute shrinkage and selection operator (LASSO) regression analysis using k-fold cross-validation. The obtained regression coefficients were used to create a predictive model, and a receiver operating characteristic (ROC) curve was obtained to express its predictive ability. Cut-off values for each significant predictor were also identified using ROC analysis.

MAIN OUTCOME MEASURE(S)

Development of a prediction model for positive SR with TESA.

RESULTS

Overall, a positive SR was observed in 23.6% of patients undergoing TESA. Average testis size (P = .017) and serum follicle-stimulating hormone (FSH) level (P < .001) were the significant predictors of positive SR identified by LASSO regression analysis. The predictive model had an AUC of 0.742 with a sensitivity of 73.9% and specificity of 69.9%. Patients presenting with an average testis size >7.75 mL and serum FSH level <8.5 IU/L had a TESA-positive SR of 43%.

CONCLUSIONS

TESA may be a suitable alternative to microTESE in selected nonobstructive azoospermia patients presenting with an average testis size >7.75 mL and serum FSH level <8.5 IU/L.

Health and fertility of ICSI-conceived young men: study protocol

STUDY QUESTIONS

What are the long-term health and reproductive outcomes for young men conceived using ICSI whose fathers had spermatogenic failure (STF)? Are there epigenetic consequences of ICSI conception?

WHAT IS KNOWN ALREADY

Currently, little is known about the health of ICSI-conceived adults, and in particular the health and reproductive potential of ICSI-conceived men whose fathers had STF. Only one group to date has assessed semen parameters and reproductive hormones in ICSI-conceived men and suggested higher rates of impaired semen quality compared to spontaneously conceived (SC) peers. Metabolic parameters in this same cohort of men were mostly comparable. No study has yet evaluated other aspects of adult health.

STUDY DESIGN SIZE DURATION

This cohort study aims to evaluate the general health and development (aim 1), fertility and metabolic parameters (aim 2) and epigenetic signatures (aim 3) of ICSI-conceived sons whose fathers had STF (ICSI study group). There are three age-matched control groups: ICSI-conceived sons whose fathers had obstructive azoospermia (OAZ) and who will be recruited in this study, as well as IVF sons and SC sons, recruited from other studies. Of 1112 ICSI parents including fathers with STF and OAZ, 78% (n = 867) of mothers and 74% (n = 823) of fathers were traced and contacted. Recruitment of ICSI sons started in March 2017 and will finish in July 2020. Based on preliminary participation rates, we estimate the following sample size will be achieved for the ICSI study group: mothers n = 275, fathers n = 225, sons n = 115. Per aim, the sample sizes of OAZ-ICSI (estimated), IVF and SC controls are: Aim 1-OAZ-ICSI: 28 (maternal surveys)/12 (son surveys), IVF: 352 (maternal surveys)/244 (son surveys), SC: 428 (maternal surveys)/255 (son surveys); Aim 2-OAZ-ICSI: 12, IVF: 72 (metabolic data), SC: 391 (metabolic data)/365 (reproductive data); Aim 3-OAZ-ICSI: 12, IVF: 71, SC: 292.

PARTICIPANTS/MATERIALS SETTING METHODS

Eligible parents are those who underwent ICSI at one of two major infertility treatment centres in Victoria, Australia and gave birth to one or more males between January 1994 and January 2000. Eligible sons are those aged 18 years or older, whose fathers had STF or OAZ, and whose parents allow researchers to approach sons. IVF and SC controls are age-matched men derived from previous studies, some from the same source population. Participating ICSI parents and sons complete a questionnaire, the latter also undergoing a clinical assessment. Outcome measures include validated survey questions, physical examination (testicular volumes, BMI and resting blood pressure), reproductive hormones (testosterone, sex hormone-binding globulin, FSH, LH), serum metabolic parameters (fasting glucose, insulin, lipid profile, highly sensitive C-reactive protein) and semen analysis. For epigenetic and future genetic analyses, ICSI sons provide specimens of blood, saliva, sperm and seminal fluid while their parents provide a saliva sample. The primary outcomes of interest are the number of mother-reported hospitalisations of the son; son-reported quality of life; prevalence of moderate-severe oligozoospermia (sperm concentration <5 million/ml) and DNA methylation profile. For each outcome, differences between the ICSI study group and each control group will be investigated using multivariable linear and logistic regression for continuous and binary outcomes, respectively. Results will be presented as adjusted odds ratios and 95% CIs.

STUDY FUNDING/COMPETING INTERESTS

This study is funded by an Australian National Health and Medical Research Council Partnership Grant (NHMRC APP1140706) and was partially funded by the Monash IVF Research and Education Foundation. L.R. is a minority shareholder and the Group Medical Director for Monash IVF Group, and reports personal fees from Monash IVF group and Ferring Australia, honoraria from Ferring Australia, and travel fees from Merck Serono, MSD and Guerbet; R.J.H. is the Medical Director of Fertility Specialists of Western Australia and has equity in Western IVF; R.I.M. is a consultant for and a shareholder of Monash IVF Group and S.R.C. reports personal fees from Besins Healthcare and non-financial support from Merck outside of the submitted work. The remaining authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

Not applicable.

TRIAL REGISTRATION DATE

Not applicable.

DATE OF FIRST PATIENT’S ENROLMENT

Not applicable.

Indication for Y Chromosome Microdeletion Analysis in Infertile Men: Is a New Sperm Concentration Threshold Needed?

OBJECTIVE

To describe the prevalence of Y-chromosome deletions in patients with a sperm concentration of less than 5 million/mL. To also determine a new sperm threshold for Y-chromosome analysis in men with infertility.

METHODS

A total of 3023 patients who had a semen concentration of less than 5 million/mL included in this retrospective study. All of these patients had a genetic evaluation, hormonal evaluation, and 2 abnormal semen analyses.

RESULTS

Y-chromosome deletions were present in 116 (3.8 %) patients with sperm concentration <5 million/mL. The frequency of a Y-chromosome deletions was 6.8%, 1.0%, 0.15% in azoospermic men, in men with sperm concentrations of 0-1 million /mL, in men with sperm concentrations of 1-5 million/mL. Patients were divided into 2 groups regarding the determined new sperm threshold. The sensitivity and specificity of the Y-chromosome deletions test were 92.2.7% and 49.3 %, 99.1%, and 22.1% in patients with azoospermia and sperm concentrations <1 million/mL, respectively. If the sperm concentration thresholds of azoospermia or <1 million/mL, are applied, the number of tests decreased to 50.5% (1442 tests) and 23.1% (643 tests), respectively. Approximately $108,150 and $48,225 would be saved if the sperm thresholds were azoospermia and <1 million/mL, respectively CONCLUSION: The current threshold of sperm concentration for Y-chromosome deletions is controversial. The new proposed sperm threshold for genetic testing of 1 million/mL would increase sensitivity and more cost-effective compared to the current threshold.

Partial-AZFc deletions in Chilean men with primary spermatogenic impairment: gene dosage and Y-chromosome haplogroups

PURPOSE

To investigate the association of partial-AZFc deletions in Chilean men with primary spermatogenic failure and their testicular histopathological phenotypes, analyzing the contribution of DAZ dosage, CDY1 copies, and Y-chromosome haplogroups.

SUBJECTS AND METHODS

We studied 479 Chilean men: 334 infertile patients with histological examination (233 cases with spermatogenic defects and 101 normal spermatogenesis, obstructive controls, OC), and 145 normozoospermic controls (NC). AZFc subdeletions were detected by single-tagged sequences and single nucleotide variants analysis. DAZ-copy number was quantified by real-time qPCR. Y-chromosome haplogroups (Y-hg) were hierarchically genotyped through 16 biallelic-markers.

RESULTS

The prevalence of AZFc-partial deletions was increased in cases (6%) compared with NC (1.4%) (P = 0.035). There was no difference between 143 Sertoli-cell only syndrome, 35 maturation arrest, or 35 mix atrophy patients and controls. However, gr/gr deletions were more frequent in 16 subjects with hypospermatogenesis compared with NC (P = 0.003) and OC (P = 0.013). Y-hg R was the most prevalent (~ 50%), but decreased among gr/gr deletions (21%, P = 0.03). The prevalence of Y-hg M increased in cases versus controls, both in total and non-deleted men (3.9 and 3.7% versus 0.4%, P = 0.009 and P = 0.016, respectively). Among gr/gr deletions, Y-hg H increased compared with non-deleted men (14.3% versus 0.4%, P = 0.0047).

CONCLUSION

Partial-AZFc deletions in a Chilean admixed population are associated with secretory azo/oligozoospermia and might have a role in the development of hypospermatogenesis. Low represented haplogroups, Y-hg M and Y-hg H, show an association with the occurrence of spermatogenic failure and gr/gr deletions respectively; however, additional studies are required.

Acrocentric Chromosome Polymorphic Variants on Chinese Female Have Possible Association with Unexplained Recurrent Pregnancy Loss

Recurrent pregnancy loss (RPL) occurs frequently in Chinese patients, but the causes for 40-50% RPL remain unexplained. This study aims to explore possible association between recurrent pregnancy loss and chromosome polymorphism. We performed a retrospective cohort study including a total number of 2967 Chinese patients from January in 2013 to December in 2019.These participants were divided into two groups: group I (RPL group) and group II (control group). Group I included 1791 patients who underwent RPL. Group II included 1176 individuals who underwent primary infertility. Their chromosome karyotype analyses were performed by Giemsa banding protocol. Pearson chi-squared test and Fisher's exact test were employed to evaluate the difference in frequency of chromosomal polymorphic variations between both groups. Chromosomal polymorphism occurred more frequently in RPL group compared with control group, the differences for 9qh+, inv(9), and Yqh+ between both groups were (χ² = 6.697, p = 0.01), (χ² = 6.242, p = 0.012), and (χ² = 4.587, p = 0.032), respectively. The most significant difference of chromosomal polymorphism karyotype between RPL group and control group was found for acrocentric chromosome (D/G group) variants (χ² = 30.7, p < 0.001). Moreover, the difference in frequency of D/G group variants between women and men in RPL group was remarkably significant (χ² = 55.3, p < 0.001), and furthermore, D/G group variants occurred more frequently among women in RPL group than women in control group (χ² = 44.3, p < 0.001). We found that acrocentric chromosomal polymorphism occurred preferentially on Chinese women with RPL. The fascinating finding provides us novel insight into the potential association of higher frequency of acrocentric chromosomal variations on Chinese women with unexplained RPL.

Genetic disorders and male infertility

BACKGROUND

At present, one out of six couples is infertile, and in 50% of cases, infertility is attributed to male infertility factors. Genetic abnormalities are found in 10%-20% of patients showing severe spermatogenesis disorders, including non-obstructive azoospermia.

METHODS

Literatures covering the relationship between male infertility and genetic disorders or chromosomal abnormalities were studied and summarized.

MAIN FINDINGS RESULTS

Genetic disorders, including Klinefelter syndrome, balanced reciprocal translocation, Robertsonian translocation, structural abnormalities in Y chromosome, XX male, azoospermic factor (AZF) deletions, and congenital bilateral absence of vas deferens were summarized and discussed from a practical point of view. Among them, understanding on AZF deletions significantly changed owing to advanced elucidation of their pathogenesis. Due to its technical progress, AZF deletion test can reveal their delicate variations and predict the condition of spermatogenesis. Thirty-nine candidate genes possibly responsible for azoospermia have been identified in the last 10 years owing to the advances in genome sequencing technologies.

CONCLUSION

Genetic testing for chromosomes and AZF deletions should be examined in cases of severe oligozoospermia and azoospermia. Genetic counseling should be offered before and after genetic testing.

Deletion of b1/b3 shows risk for expanse of Yq microdeletion in male offspring: Case report of novel Y chromosome variations

RATIONALE

This study aimed to report 1 family case with novel Y chromosome structural variations by an established next-generation sequencing (NGS) method using unique STSs.

PATIENT CONCERNS

The case studied was from a family with a father and son (the proband). G-band staining was used for karyotype analysis. Y chromosome microdeletions were detected by sequence-tagged site (STS)-PCR analysis and a new NGS screening strategy.

DIAGNOSES

Semen analysis showed that the proband was azoospermic. The patient had an abnormal karyotype (45,X[48%]/46,XY[52%]). His father exhibited a normal karyotype. STS-PCR analysis showed that the proband had a deletion of the AZFb+c region, and his father had no deletion of STS markers examined. The sequencing method revealed that the patient had DNA sequence deletions from nt 20099846 to nt 28365090 (8.3 Mb), including the region from yel4 to the Yq terminal, and his father exhibited a deletion of b1/b3 and duplication of gr/gr.

INTERVENTIONS

The proband was advised to undergo genetic counseling, and consider the use of sperm from a sperm bank or adoption to become a father.

OUTCOMES

The proband was azoospermic. AZFc partial deletions may produce a potential risk for large AZFb+c deletions or abnormal karyotypes causing spermatogenic failure in men.

LESSONS

The NGS method can be considered a clinical diagnostic tool to detect Y chromosome microdeletions. The partial AZFc deletions and/or duplications can be a risk of extensive deletions in offspring.

Case report: A non-obstructive azoospermia patient with heat shock factor-2 mutation

RATIONALE

Infertility is a common medical condition that affects nearly 15% of the world population. Non-obstructive azoospermia (NOA) is one of the most severe forms of male infertility. Some common structural variants, single nucleotide polymorphisms (SNPs), and genetic factors were reported to be associated with NOA. However, the underlying etiology and genetic mechanism(s) remain largely unclear. This report aimed to describe the associated mutation of the heat shock factor-2 (HSF2) gene in Chinese infertile men with NOA.

PATIENT CONCERNS

An apparently healthy 27-year-old man with a body mass index (BMI) of 23.31 kg/m had a 2-year history of primary infertility.

DIAGNOSES

The semen analysis of the patient showed a sperm concentration of 0/mL in 6.5 mL of semen. The patient was diagnosed with NOA by performing the comprehensive examinations including a detailed medical history, physical examination, chromosome analysis, Y-chromosome microdeletions, semen analysis, and hormone profiles.

INTERVENTIONS

The couple received artificial insemination by donor (AID) and a healthy girl was born after the embryo transfer.

OUTCOMES

We found a novel deletion-insertion variation c.326_326delinsGGAAGGTGAGCTATTGT in the exon 3 of the HSF2 gene by performing next-generation sequencing on him who was diagnosed NOA. We performed Sanger sequencing on this patient and confirmed the heterozygous missing insertion mutation in the patient. This is a novel mutation. The variant was heterozygous and categorized as pathogenic.

LESSONS

A novel deletion-insertion variation c.326_326delinsGGAAGGTGAGCTATTGT in the exon 3 of HSF2 gene HSF2 is predicted to be pathogenic and associated with the occurrence of NOA.

Application of Y-chromosomal microdeletions in a homicide case

A case study involving an intentional homicide case in November 2018, in which the autosomal genotypes of the suspect were unavailable and only part of deletions of Y-STR loci were identified by Y-chromosomal typing. The suspect, male, was charged with beating the decedent, female, over the head with an iron water pipe to death. The use of standard autosomal DNA profiling to identify the suspect was unattainable due to the extensive volume blood of the decedent on the murder weapon which was inevitably cleaned by running water at the crime scene. As a result, autosomal genotypes of the suspect were unavailable and only partial samples of deletions of Y-STR loci were identified by Y-chromosomal typing. Y-STR analysis (Yfiler™ plus and AGCU Y36) was used on the collected DNA extracts and compared to reference samples of the suspect, as well as his father and brother in an attempt to positively identify the suspect as the perpetrator of the murder. Subsequent Y-STR genotyping for the suspect, his father and brother indicated that Y-STR genotype of the suspect was consistent with that discovered on the physical evidence and the deleted Y-STR loci were identical for both. No deletions of Y-STR genotype were observed in the suspect's father and brother. After changing a Y-STR kit, the deleted loci were still present in the suspect. In Addition, sequencing of the whole Y-chromosomal genes was performed on the samples taken from the suspect and his father and brother. Segmental deletions at Yq 11.222-Yq 11.23 of the suspect were observed and the deleted Y-STR markers were right on the deleted Y-chromosomal segments. In this case, although the suspect could not be identified by the autosomal STR profiles detected on the physical evidence, the discovery of identical Y-STR genotype and the identical deletions of Y-chromosomal segments made it plausible that DNA on the murder weapon was left behind by the suspect. This case study shows that in criminal cases like this, where the autosomal STR evidence is unattainable, Y-STR evidence can be used effectively as a substitute to identify the suspect.

[Andrological diagnostics prior to treatment by assisted reproduction]

Infertility is defined as the inability of a couple to succeed in achieving a spontaneous pregnancy after 1 year. Male and female factors contribute to infertility with approximately 40% each. In the remaining cases factors that affect fertility can be found in both partners. The andrological work-up should be started simultaneously with the gynecological diagnostic procedure in order to identify and treat andrological factors related to infertility. Since the majority of intracytoplasmic sperm injection procedures are performed due to andrological infertility, andrological diagnostics can prevent a delay in assisted reproductive technology. The andrological work-up can be necessary before 12 months of unsuccessful conception if the female partner is older than 35 years or andrological factors are present that could impair male fertility.

Diagnosis and hormonal treatment of male infertility

Male infertility is a frequently observed medical condition that is related to the functioning of extremely complex organs such as the pituitary gland and the gonads. The diagnosis and proper management of infertile men is challenging for modern medicine, given the high expectations and demands of current patients, mainly due to the economic and emotional expenses aroused by this "relationship issue". In many cases, patients should receive therapies aimed at improving the functioning of that complex hormonal axis, instead of treating their underlying problem; thus, seeking to optimize the production of gametes with better conditions and improve fertilization rates without requiring assisted procedures.

Infertility: Practical Clinical Issues for Routine Investigation of the Male Partner

About one-fifth of couples has fertility problems in Western countries. Male factors are present in about half of them, either alone or in combination with female causes. Therefore, both partners should be evaluated simultaneously. The fertility status and/or specific conditions of each partner influence the clinical and treatment approach. This article summarizes in a practical way when, how, and why the male partner of an infertile couple should be investigated. The available evidence and international guidelines were used, interpreting, discussing, and expanding them from personal decades-long experience in this field. The aim is to delineate the most appropriate clinical approach for the male partner of infertile couples, considering traditional and emerging technologies and laboratory analyses in the context of their clinical significance. Components of the initial evaluation in men without known risk factors for infertility should include at minimum medical history, physical examination, and semen analysis. Semen microbiological examination, endocrine assessment, scrotal ultrasound, and transrectal ultrasound are suggested in most men and are mandatory when specific risk factors for male infertility are known to be present or when the initial screening demonstrated abnormalities. Full examination, including genetic tests, testicular histology, or additional tests on sperm, is clinically oriented and/or suggested after the results of initial investigations.

Molecular delineation of small supernumerary marker chromosomes using a single nucleotide polymorphism array

Background

Defining the phenotype-genotype correlation of small supernumerary marker chromosomes (sSMCs) remains a challenge in prenatal diagnosis. We karyotyped 20,481 amniotic fluid samples from pregnant women and explored the molecular characteristics of sSMCs using a single nucleotide polymorphism (SNP) array.

Results

Out of the 20,481 samples, 15 abnormal karyotypes with sSMC were detected (frequency: 0.073%) and the chromosomal origin was successfully identified by SNP array in 14 of them. The origin of sSMCs were mainly acrocentric-derived chromosomes and the Y chromosome. Two cases of sSMC combined with uniparental disomy (UPD) were detected, UPD(1) and UPD(22). More than half of the cases of sSMC involved mosaicism (8/15) and pathogenicity (9/15) in prenatal diagnosis. A higher prevalence of mosaicism for non-acrocentric chromosomes than acrocentric chromosomes was also revealed. One sSMC derived from chromosome 3 with a neocentromere revealed a 24.99-Mb pathogenic gain of the 3q26.31q29 region on the SNP array, which presented as an abnormal ultrasound indicating nasal bone hypoplasia.

Conclusion

The clinical phenotypes of sSMCs are variable and so further genetic testing and parental karyotype analysis are needed to confirm the characteristics of sSMCs. The SNP array used here allows a detailed characterisation of the sSMC and establishes a stronger genotype-phenotype correlation, thus allowing detailed genetic counselling for prenatal diagnosis.

Efficacy of MLPA for detection of Y-chromosome microdeletions in infertile Brazilian patients

PURPOSE

Worldwide publications follow the gold standard method-the polymerase chain reaction (PCR)-for detecting Y-chromosome microdeletions; however, markers are frequently variable between the studies. Can we detect the deletions by another molecular method with more genomic coverage? The Y chromosome harbors several different genes responsible for testicular development and spermatogenesis, and its repetitive conformation predisposes it to complex rearrangements that have clinical impact. Our aim was to evaluate a molecular diagnostic method, the Multiplex Ligand Probe-dependent Amplification (MLPA), which is also a valuable ancillary method for the identification of deletions, duplications, and rearrangements in a single and faster reaction, leading to a better comprehension of patients' phenotypes, and should be considered a useful tool for detection of Y chromosome deletions.

METHODS

This is a study of diagnostic accuracy (transversal prospective study) conducted to investigate Y-chromosome deletions in 84 individuals through PCR and MLPA methods. Forty-three infertile men (azoospermic and oligozoospermic) and 41 controls (40 fertile men and 1 normal karyotyped woman) were analyzed by PCR and MLPA techniques.

RESULTS

We diagnosed seven (7) deletions (16.2%) by PCR and 9 with MLPA (21%). In addition, we found five (5) duplications and a suggestive mosaic.

CONCLUSION

Our results demonstrate that MLPA technique is valuable in the investigation of microdeletions and microduplications. Besides deletions, duplications can cause instability of chromosome genes, possibly leading to infertility. Both studied techniques provide an advantageous diagnostic strategy, thus enabling a better genetic counseling.

Nonmosaic Trisomy 19p13.3p13.2 Resulting from a Rare Unbalanced t(Y;19)(q12;p13.2) Translocation in a Patient with Pachygyria and Polymicrogyria

Nonmosaic trisomy involving 19p13.3p13.2 is a very uncommon abnormality. At present, only 12 cases with this genetic condition have been reported in the literature. However, the size of the trisomic fragment is heterogeneous and thus, the clinical spectrum is variable. Herein, we report the clinical and cytogenetic characterization of a 5-year-old boy with nonmosaic trisomy 19p13.3p13.2 (7.38 Mb), generated by a derivative Y chromosome resulting from a de novo unbalanced translocation t(Y;19)(q12;p13.2). We demonstrated the integrity of the euchromatic regions in the abnormal Y chromosome to confirm the pure trisomy 19p. Our patient shares some clinical features described in other reported patients with pure trisomy 19p, such as craniofacial anomalies, developmental delay, and heart defects. Different to previous reports, our case exhibits frontal pachygyria and polymicrogyria. These additional features contribute to further delineate the clinical spectrum of trisomy 19p13.3p13.2.

Is the primary AZFc duplication a potential risk for male infertility?: A systematic review and meta-analysis

BACKGROUND

Numerous studies have been performed to investigate the association between the primary AZFc duplication and male infertility risk; however, the sample sizes have been small and the results have been controversial. A meta-analysis was performed to assess these associations.

METHODS

A systematic search was conducted to identify all relevant studies from the PubMed, Web of Science, Medline, CNKI, and Wanfang databases up to October 22, 2019. The odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the strength of associations. All of the statistical analyses were conducted by using RevMan 5.3.

RESULTS

Eleven studies were identified that involved 3140 infertile men and 2280 fertile men. Overall, there was a statistically significant association between the primary AZFc duplication and male infertility (OR = 1.66, 95% CI  = 1.29-2.14, P < .0001). In the subgroup analysis by ethnic group, a statistically significant association between the primary AZFc duplication and male infertility was observed in Asian men (OR  =  2.26, 95% CI  = 1.64-3.12, P < .00001), but not in European men (OR  =  0.90, 95% CI = 0.59-1.38, P = .64). For subtypes of the primary AZFc duplication, a statistically significant association was observed between the gr/gr duplication-only (OR  = 2.71, 95% CI  = 1.38-5.32, P = .004) and infertility in Asian men. Asian men with the primary AZFc duplication resulting in more than four DAZ genes were found to be at an increased risk for infertility (OR  = 2.70, 95% CI  = 1.49-4.89, P = .001).

CONCLUSION

Our meta-analysis provides an unprecedented illustration of how the association between the primary AZFc duplication and male infertility may be dependent on ethnicity or geographic location. Furthermore, gr/gr duplication or increased DAZ copy number can be detrimental to spermatogenesis in Asian men.

Utility of micro-TESE in the most severe cases of non-obstructive azoospermia

The use of intracytoplasmic sperm injection (ICSI) has been a major breakthrough in the treatment of male infertility. Even patients with non-obstructive azoospermia (NOA) may benefit from the ICSI technique to father a child as long as spermatogenesis is present. There are several techniques to recover testicular sperm in patients with NOA. However, retrieval of spermatozoa is unfortunately still only successful in a subset of patients with NOA, and the most superior sperm retrieval method is still under debate. A more recent technique, microdissection testicular sperm extraction (MD-TESE) with an operative microscope collecting larger and more opaque seminiferous tubules, is a non-blind sperm retrieval technique with theoretical benefits. The MD-TESE procedure seems to be feasible, effective, and safe in NOA patients but also more technically demanding and time-consuming compared with conventional blind techniques. In the present report, we describe our clinical experience and results from our first 159 MD-TESE procedures. The probability to retrieve sperm with the MD-TESE technique is high in NOA cases where earlier sperm retrieval with blind methods such as needle aspiration, percutaneous needle biopsy, or conventional TESE has failed.

First custom next-generation sequencing infertility panel in Latin America: design and first results

Objective

To present the development of the first custom gene panel for the diagnosis of male and female infertility in Latin America.

Methods

We developed a next-generation sequencing (NGS) panel that assesses genes associated with infertility. The panel targeted exons and their flanking regions. Selected introns in the CFTR gene were also included. The FMR1 gene and Y chromosome microdeletions were analyzed with other recommended methodologies. An in-house developed bioinformatic pipeline was applied for the interpretation of the results. Clear infertility phenotypes, idiopathic infertility, and samples with known pathogenic variants were evaluated.

Results

A total of 75 genes were selected based on female (primary ovarian insufficiency, risk of ovarian hyperstimulation syndrome, recurrent pregnancy loss, oocyte maturation defects, and embryo development arrest) and male conditions (azoospermia, severe oligospermia, asthenozoospermia, and teratozoospermia). The panel designed was used to assess 25 DNA samples. Two of the variants found were classified as pathogenic and enable the diagnosis of a woman with secondary amenorrhea and a man with oligoasthenoteratozoospermia. Targeted NGS assay metrics resulted in a mean of 180X coverage, with more than 98% of the bases covered ≥20X.

Conclusion

Our custom gene sequencing panel designed for the diagnosis of male and female infertility caused by genetic defects revealed the underlying genetic cause of some cases of infertility. The panel will allow us to develop more precise approaches in assisted reproduction.

Role of genetics and epigenetics in male infertility

Male infertility is a complex condition with a strong genetic and epigenetic background. This review discusses the importance of genetic and epigenetic factors in the pathophysiology of male infertility. The interplay between thousands of genes, the epigenetic control of gene expression, and environmental and lifestyle factors, which influence genetic and epigenetic variants, determines the resulting male infertility phenotype. Currently, karyotyping, Y-chromosome microdeletion screening and CFTR gene mutation tests are routinely performed to investigate a possible genetic aetiology in patients with azoospermia and severe oligozoospermia. However, current testing is limited in its ability to identify a variety of genetic and epigenetic conditions that might be implicated in both idiopathic and unexplained infertility. Several epimutations of imprinting genes and developmental genes have been postulated to be candidate markers for male infertility. As such, development of novel diagnostic panels is essential to change the current landscape with regard to prevention, diagnosis and management. Understanding the underlying genetic mechanisms related to the pathophysiology of male infertility, and the impact of environmental exposures and lifestyle factors on gene expression might aid clinicians in developing individualised treatment strategies.

Genetische Diagnostik vor assistierter Reproduktion – Empfehlungen der neuen S2k-Leitlinie 2019

Genetische Ursachen sind für etwa 10–20 % der männlichen und 5–10 % der weiblichen In- oder Subfertilität verantwortlich. Bei Männern ist die andrologische Untersuchung Voraussetzung dafür, genetische Ursachen von Spermatogenesestörungen einordnen zu können. Außer Störungen der Geschlechtschromosomen können auch balancierte Chromosomenumbauten zu einer Fertilitätsminderung führen. Eine Azoospermiefaktoranalyse in Bezug auf Y‑chromosomale Mikrodeletionen ist bei Männern mit Azoospermie indiziert, da sie über den Erfolg einer assistierten Reproduktion entscheiden kann. Bei Verdacht auf obstruktive Azoospermie soll eine Analyse des CFTR-Gens zur Diagnostik einer zystischen Fibrose erfolgen. Bei endokrinen Auffälligkeiten sind genetische Ursachen des häufigeren hypergonadotropen Hypogonadismus von denen eines seltenen kongenitalen hypogonadotropen Hypogonadismus zu unterscheiden. Algorithmen zur genetischen Diagnostik sind in der aktuellen Leitlinie im internationalen Vergleich ausgeführt.

Evaluation from a different perspective of 10-year results of infertile males with Y chromosome AZFc microdeletions compared with a control group

AZFc microdeletions will be evaluated upon being divided into partial and complete subgroups. The association of deletions with reactive oxidative stress (ROS) and sperm DNA fragmentation (SDFI) and the impact of their coexistence on fertility starting from the pregnancy process until live birth will be presented. Semen analyses, microbiological results, hormones, ROS and sperm TUNEL tests were checked. Preimplantation genetic testing (PGT) was planned for relevant patients. Intracytoplasmic sperm injection (ICSI) was applied. Their embryo fragmentation was monitored via time lapse. Their results were compared with those with no AZF deletion and no other genetic problems. Azoospermia rate was 71.5%, m-TESE success rate was 25%, pregnancy rate was 26% and live child rate was 2.2%. No difference was detected between the partial and total groups in terms of ROS and SDFI rates and no difference was identified with the control group. Better results were obtained in terms of live child rate in patients with partial AZFc and low ROS/SDFI. Spermatozoon was retrieved in AZFc deletions and pregnancy, and live child was identified. No AZFc impact was observed on ROS and SDFI in the results compared with the control groups in terms of their coexistence.

Clinical outcomes of microdissection testicular sperm extraction and intracytoplasmic sperm injection in Japanese men with Y chromosome microdeletions

PURPOSE

We investigated the clinical results of Japanese men with Y chromosome microdeletions.

METHODS

This study retrospectively examined 2163 azoospermic or severe oligozoospermic patients. We investigated the frequency of azoospermia factor (AZF) deletions and sperm retrieval rate (SRR) by microTESE in patients with these deletions, then analyzed the ICSI outcomes.

RESULTS

Azoospermia factor deletions were found in 201 patients. SRR was significantly higher than that of the control group (74.0% vs 20.4%, P < .001). Thirty-three couples underwent ICSI using testicular spermatozoa retrieved by microTESE, and eight couples underwent ICSI using ejaculatory spermatozoa. The fertilization rate and clinical pregnancy rate per embryo transfer cycle were significantly higher in the ejaculatory group than that of the testicular group (66.4% vs 43.7%, P < .001, 53.3% vs 24.7%, P = .03, respectively). When compared with the control group, the fertilization rate was significantly lower in the testicular group with AZFc microdeletions (43.7% vs 53.6%, P < .001).

CONCLUSIONS

Our study highlights that although microTESE in azoospermic men with AZFc microdeletions led to a higher SRR, ICSI outcomes of these men were worse than that of men without AZF deletions, even if testicular spermatozoa were retrieved.

Evaluation of chromosomal abnormalities and Y-chromosome microdeletions in 1696 Turkish cases with primary male infertility: A single-center study

OBJECTIVE

The aim of this study was to determine the frequencies of chromosomal abnormalities and Y-chromosome microdeletions in Turkish cases with primary male infertility in a single center.

MATERIAL AND METHODS

Chromosomal abnormalities and Y-chromosome microdeletions were investigated in 1696 cases with primary male infertility between 2012 and 2017. Karyotype analyzes and Y-chromosome microdeletions analyzes [azoospermia factor (AZF) regions] were performed in all cases by using standard cytogenetic methods and the multiplex polymerase chain reaction method, respectively.

RESULTS

Chromosomal abnormalities were found in 142 cases (8.4%; 142/1696). Y-chromosome microdeletions were detected in 46 cases (2.7%; 46/1696). Y-chromosome microdeletions in the AZFc region were found in 20 of 46 cases (43%).

CONCLUSION

This study is one of the few were a large number of cases was studied in Turkey. It indicates that cytogenetic and Y-chromosome microdeletion studies should be conducted in cases with primary male infertility prior to selecting assisted reproductive techniques.

Do partial AZFc deletions affect the sperm retrieval rate in non-mosaic Klinefelter patients undergoing microdissection testicular sperm extraction?

BACKGROUND

The purpose of this study is to evaluate the prognostic factors for sperm retrieval and determine if Y chromosome deletion is associated with deleterious effects on spermatogenesis in non-mosaic Klinefelter patients. Whether Y chromosome deletion determines the sperm retrieval rate in non-mosaic Klinefelter patients has not yet been addressed.

METHODS

We retrospectively collected medical records of azoospermic patients from Sep 2009 to Dec 2018, and enrolled 66 non-mosaic 47, XXY patients who were receiving mTESE. The predictive values of patients age, serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, prolactin, estradiol and Y chromosome deletion were assessed for successful sperm recovery.

RESULTS

Testicular sperm recovery was successful in 24 (36.4%) of 66 men. The mean age (36.0 vs. 36.6 years), and levels of FSH (30.0 vs 36.9 IU/L), LH (17.7 vs 21.9 IU/L), testosterone (2.4 vs. 2.1 ng/ml), prolactin (9.1 vs. 8.8 ng/ml), and estradiol (19.4 vs. 22.3 pg/ml) did not show any significant difference when comparing patients with and without successful sperm retrieval. Partial deletion of azoospermic factor c (AZFc) was noted in 5 (20.8%) of 24 patients with successful sperm retrieval, including three b2/b3 and two gr/gr deletion cases, whereas 4 (9.5%) of 42 patients with unsuccessful sperm retrieval were noted to have AZFc partial deletion (one b2/b3, one sY1206 and two gr/gr deletion), though the difference was not statistically significant (p = 0.27).

CONCLUSION

According to present results, age and AZFc partial deletion status should not be a deterrent for azoospermic males with non-mosaic Klinefelter syndrome to undergo mTESE.

The association of gr/gr deletion in the Y chromosome and impaired spermatogenesis in Bulgarian males: a pilot study

Background

The microdeletions of the Y chromosome are associated with a decreased number of sperm cells in the ejaculate and male infertility. One such deletion is the gr/gr, which leads to reduction of the alleles in the DAZ gene. In order to evaluate its role, 30 patients with sperm count below 5 × 106/mL and 30 normal fertile men were genotyped for microdeletions in Azoospermia Factor (AZF) region, including gr/gr deletion.

Results

Twenty-one men (70.00%) from the males with impaired fertility had a normal genotype, seven men (23.33%) were carriers of a gr/gr deletion, and two men (6.67%) demonstrated a deletion of the AZFc region. From the control group, there were 22 men (73.33%) with no deletion, seven (23.33%) carried a gr/gr deletion, and one man (3.33%) carried a possible deletion in the b1-b4 region of the Y chromosome. The gr/gr deletion of the Y chromosome showed a statistically nonsignificant difference (p = 0.94, alpha < 0.05) with the control group (chi-square, degrees of freedom 0.006).

Conclusion

The results from the research show no association between this deletion and male infertility in the studied population. Despite the small sample size, the high frequency of the gr/gr deletion, found in the control group, suggests that this variant may not be associated with impaired spermatogenesis.

Functional characterization of the first missense variant in CEP78, a founder allele associated with cone-rod dystrophy, hearing loss, and reduced male fertility

Inactivating variants in the centrosomal CEP78 gene have been found in cone-rod dystrophy with hearing loss (CRDHL), a particular phenotype distinct from Usher syndrome. Here, we identified and functionally characterized the first CEP78 missense variant c.449T>C, p.(Leu150Ser) in three CRDHL families. The variant was found in a biallelic state in two Belgian families and in a compound heterozygous state-in trans with c.1462-1G>T-in a third German family. Haplotype reconstruction showed a founder effect. Homology modeling revealed a detrimental effect of p.(Leu150Ser) on protein stability, which was corroborated in patients' fibroblasts. Elongated primary cilia without clear ultrastructural abnormalities in sperm or nasal brushes suggest impaired cilia assembly. Two affected males from different families displayed sperm abnormalities causing infertility. One of these is a heterozygous carrier of a complex allele in SPAG17, a ciliary gene previously associated with autosomal recessive male infertility. Taken together, our data indicate that a missense founder allele in CEP78 underlies the same sensorineural CRDHL phenotype previously associated with inactivating variants. Interestingly, the CEP78 phenotype has been possibly expanded with male infertility. Finally, CEP78 loss-of-function variants may have an underestimated role in misdiagnosed Usher syndrome, with or without sperm abnormalities.

A different look at genetic factors in individuals with non-obstructive azoospermia or oligospermia in our research study: To whom, which threshold, when, in what way?

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.

Prenatal genetic analysis and differential pregnancy outcomes of two de novo cases showing mosaic isodicentric Y chromosome

Background

Fetal cells collected from the amniotic fluid of two pregnant women indicated sex chromosome abnormalities. Therefore, we performed G-banded chromosome karyotype analysis, single nucleotide polymorphism array (SNP array), fluorescence in situ hybridization (FISH), and sequence-tagged sites (STS) analysis of the Y chromosome to determine the rare molecular genetics of the two fetuses.

Case presentation

The karyotypes of the fetuses from patients 1 and 2 were mos 45,X[92]/46,X,+idic(Y)(q11.21)[8] and mos 45,X[20]/46,X,+idic(Y)(q11.223)[80], respectively. Fetus 1 had a 7.76 Mb deletion in Yq11.222q11.23 and a 15.68 Mb duplication in Yp11.2q11.21. Fetus 2 had 21 Mb of repetitive segments in Yp11.3q11.223. Azoospermia factor (AZF) detection by STS analysis revealed a missing AZFb+c region in fetus 1 and three functional AZF regions in fetus 2. The isodicentric Y chromosome (idic (Y)) in both fetuses arose de novo. The pregnancy of patient 1 was terminated, whereas the fetus of patient 2 was delivered and is now 10 months old with normal appearance and growth.

Conclusion

A combination of technologies such as chromosome karyotyping, FISH, SNP arrays, and STS analysis of the Y chromosome is important in prenatal diagnosis to reduce birth defect rates and improve the health of the Chinese population.

Evaluating genetic causes of azoospermia: What can we learn from a complex cellular structure and single-cell transcriptomics of the human testis?

Azoospermia is a condition defined as the absence of spermatozoa in the ejaculate, but the testicular phenotype of men with azoospermia may be very variable, ranging from full spermatogenesis, through arrested maturation of germ cells at different stages, to completely degenerated tissue with ghost tubules. Hence, information regarding the cell-type-specific expression patterns is needed to prioritise potential pathogenic variants that contribute to the pathogenesis of azoospermia. Thanks to technological advances within next-generation sequencing, it is now possible to obtain detailed cell-type-specific expression patterns in the testis by single-cell RNA sequencing. However, to interpret single-cell RNA sequencing data properly, substantial knowledge of the highly sophisticated data processing and visualisation methods is needed. Here we review the complex cellular structure of the human testis in different types of azoospermia and outline how known genetic alterations affect the pathology of the testis. We combined the currently available single-cell RNA sequencing datasets originating from the human testis into one dataset covering 62,751 testicular cells, each with a median of 2637 transcripts quantified. We show what effects the most common data-processing steps have, and how different visualisation methods can be used. Furthermore, we calculated expression patterns in pseudotime, and show how splicing rates can be used to determine the velocity of differentiation during spermatogenesis. With the combined dataset we show expression patterns and network analysis of genes known to be involved in the pathogenesis of azoospermia. Finally, we provide the combined dataset as an interactive online resource where expression of genes and different visualisation methods can be explored ( https://testis.cells.ucsc.edu/ ).

AZF deletions in Indian populations: original study and meta-analyses

PURPOSE

To identify the frequency of Y chromosome microdeletions in Indian populations and to quantitatively estimate the significance of association between these deletions and male infertility.

METHODS

A total of 379 infertile males (302 azoospermic and 77 oligozoospermic infertile males) and 265 normozoospermic fertile males were evaluated for Y chromosome microdeletions (YCD) using PCR amplification and gel electrophoresis. Meta-analyses were performed on AZFa (2079 cases and 1217 controls), AZFb (2212 cases and 1267 controls), AZFc (4131 cases and 2008 controls), and AZFb+c (1573 cases and 942 controls) deletions data to quantitatively estimate the significance of association between these deletions and male infertility in Indian populations.

RESULTS

The results revealed that out of 379 infertile azoospermic and oligozoospermic males, 38 (10.02%) had AZF deletions. No deletion was found in control samples. The highest percentage of deletions was observed in the AZFc region, followed by AZFa and AZFb. Qualitative analysis showed that AZF deletions were present in 0.59 to 32.62% (average 13.48%) of infertile cases in Indian populations. Meta-analysis revealed a significant association of AZFa (OR = 6.74, p value = 0.001), AZFb (OR = 4.694, p value = 0.004), AZFc (OR = 13.575, p value = 0.000), and AZFb+c (OR = 5.946, p value = 0.018) deletions with male infertility.

CONCLUSION

AZF deletions were seen in 10.02% of azoospermic and oligozoospermic cases with the highest frequency of AZFc deletions. Pooled analysis for all studies showed deletion frequency from 0.59 to 32.62% (average = 13.48%). Meta-analysis showed significant association of AZFa, AZFb, and AZFb+c deletions with male infertility. Analysis of Y chromosome microdeletions should be reckoned as an essential testing for diagnostic and therapeutic purposes.

The Role of Number of Copies, Structure, Behavior and Copy Number Variations (CNV) of the Y Chromosome in Male Infertility

The World Health Organization (WHO) defines infertility as the inability of a sexually active, non-contracepting couple to achieve spontaneous pregnancy within one year. Statistics show that the two sexes are equally at risk. Several causes may be responsible for male infertility; however, in 30–40% of cases a diagnosis of idiopathic male infertility is made in men with normal urogenital anatomy, no history of familial fertility-related diseases and a normal panel of values as for endocrine, genetic and biochemical markers. Idiopathic male infertility may be the result of gene/environment interactions, genetic and epigenetic abnormalities. Numerical and structural anomalies of the Y chromosome represent a minor yet significant proportion and are the topic discussed in this review. We searched the PubMed database and major search engines for reports about Y-linked male infertility. We present cases of Y-linked male infertility in terms of (i) anomalies of the Y chromosome structure/number; (ii) Y chromosome misbehavior in a normal genetic background; (iii) Y chromosome copy number variations (CNVs). We discuss possible explanations of male infertility caused by mutations, lower or higher number of copies of otherwise wild type, Y-linked sequences. Despite Y chromosome structural anomalies are not a major cause of male infertility, in case of negative results and of normal DNA sequencing of the ascertained genes causing infertility and mapping on this chromosome, we recommend an analysis of the karyotype integrity in all cases of idiopathic fertility impairment, with an emphasis on the structure and number of this chromosome.

The X chromosome and male infertility

The X chromosome is a key player in germ cell development, as has been highlighted for males in previous studies revealing that the mammalian X chromosome is enriched in genes expressed in early spermatogenesis. In this review, we focus on the X chromosome’s unique biology as associated with human male infertility. Male infertility is most commonly caused by spermatogenic defects to which X chromosome dosage is closely linked; for example, any supernumerary X chromosome as in Klinefelter syndrome will lead to male infertility. Furthermore, because males normally only have a single X chromosome and because X-linked genetic anomalies are generally only present in a single copy in males, any loss-of-function mutations in single-copy X-chromosomal genes cannot be compensated by a normal allele. These features make X-linked genes particularly attractive for studying male spermatogenic failure. However, to date, only very few genetic causes have been identified as being definitively responsible for male infertility in humans. Although genetic studies of germ cell-enriched X-chromosomal genes in mice suggest a role of certain human orthologs in infertile men, these genes in mice and humans have striking evolutionary differences. Furthermore, the complexity and highly repetitive structure of the X chromosome hinder the mutational analysis of X-linked genes in humans. Therefore, we conclude that additional methodological approaches are urgently warranted to advance our understanding of the genetics of X-linked male infertility.

Diagnosis and Treatment Before Assisted Reproductive Treatments. Guideline of the DGGG, OEGGG and SGGG (S2k Level, AWMF Register Number 015-085, February 2019) - Part 2, Hemostaseology, Andrology, Genetics and History of Malignant Disease

Introduction Supporting and counselling couples with fertility issues prior to starting ART is a multidisciplinary diagnostic and therapeutic challenge. The first German-language interdisciplinary S2k guideline on "Diagnosis and Therapy Before Assisted Reproductive Treatments (ART)" was published in February 2019. The guideline was developed in the context of the guidelines program of the German Society of Gynecology and Obstetrics (DGGG) in cooperation with the Swiss Society of Gynecology and Obstetrics (SGGG) and the Austrian Society of Gynecology and Obstetrics (OEGGG). Aim In one third of cases, the cause of involuntary childlessness remains unclear, even if the woman or man have numerous possible risk factors. Because the topic is still very much taboo, couples may be socially isolated and often only present quite late to a fertility center. There is no standard treatment concept for these patients at present, as there are currently no standard multidisciplinary procedures for the diagnostic workup and treatment of infertility. The aim of this guideline is to provide physicians with evidence-based recommendations for counselling, diagnosis and treatment. Methods This S2k guideline was developed on behalf of the Guidelines Commission of the DGGG by representative members from different professional medical organizations and societies using a structured consensus process. Recommendations This second part of the guideline describes the hematological workup for women as well as additional diagnostic procedures which can be used to investigate couples and which are carried out in cooperation with physicians working in other medical fields such as andrologists, geneticists and oncologists.

The Association of Partial Azoospermia Factor C Deletions and Male Infertility in Northwestern China

BACKGROUND

Male infertility is a major health issue worldwide. Y chromosome microdeletions are well-characterized genetic causes of male infertility. The association of partial AZFc deletions (gr/gr, b2/b3, and b1/b3) with male infertility is not well confirmed in diverse populations. The purpose of the present study was to investigate the frequency of partial AZFc deletions and their association with male infertility in a population from Northwestern China.

METHODS

Multiplex polymerase chain reaction was used to detect partial AZFc deletions in 228 infertile patients. We analyzed 141 cases of azoospermia (AS), 87 cases of oligozoospermia (OS), and 200 fertile controls.

RESULTS

Our data showed that the frequency of a b2/b3 deletion in infertile men, men with AS, men with OS, and controls was 3.51, 2.13, 5.75, and 0.00%, respectively. The frequency of this deletion was significantly different between the infertile group and the control group (3.51 vs. 0.00%, respectively, p = 0.021) and between the OS group and the control group (5.75 vs. 0.00%, respectively, p = 0.003). The frequency of a gr/gr deletion in each group was 11.84, 9.22, 16.09, and 7.50%, respectively. The frequency of a gr/gr deletion was significantly different between the OS group and the control group (16.09 vs. 7.50%, respectively, p = 0.026) but not between the infertile group and the control group (11.84 vs. 7.50%, p = 0.132) or the AS group and the control group (9.22 vs. 7.50%, p = 0.569). The frequency of a b1/b3 deletion was 0.44, 0.71, 0.00, and 3.00%, respectively. For this deletion, there was no significant difference between the infertile (0.44 vs. 3.00%, p = 0.089), AS (0.71 vs. 3.00%, p = 0.276), and OS groups (0.00 vs. 3.00%, p = 0.236) and the control group.

CONCLUSIONS

Our results suggest that the b2/b3 deletion might be associated with male infertility and that the gr/gr deletion might be associated with spermatogenic failure in men with OS in Northwestern China (Ningxia).

The current status and future of andrology: A consensus report from the Cairo workshop group

BACKGROUND

In attempting to formulate potential WHO guidelines for the diagnosis of male infertility, the Evidence Synthesis Group noted a paucity of high-quality data on which to base key recommendations. As a result, a number of authors suggested that key areas of research/evidence gaps should be identified, so that appropriate funding and policy actions could be undertaken to help address key questions.

OBJECTIVES

The overall objective of this Consensus workshop was to clarify current knowledge and deficits in clinical laboratory andrology, so that clear paths for future development could be navigated.

MATERIALS AND METHODS

Following a detailed literature review, each author, prior to the face-to-face meeting, prepared a summary of their topic and submitted a PowerPoint presentation. The topics covered were (a) Diagnostic testing in male fertility and infertility, (b) Male fertility/infertility in the modern world, (c) Clinical management of male infertility, and (d) The overuse of ICSI. At the meeting in Cairo on February 18, 2019, the evidence was presented and discussed and a series of consensus points agreed.

RESULTS

The paper presents a background and summary of the evidence relating to these four topics and addresses key points of significance. Following discussion of the evidence, a total of 36 consensus points were agreed.

DISCUSSION

The Discussion section presents areas where there was further debate and key areas that were highlighted during the day.

CONCLUSION

The consensus points provide clear statements of evidence gaps and/or potential future research areas/topics. Appropriate funding streams addressing these can be prioritized and consequently, in the short and medium term, answers provided. By using this strategic approach, andrology can make the rapid progress necessary to address key scientific, clinical, and societal challenges that face our discipline now and in the near future.

Sequence analysis of 37 candidate genes for male infertility: challenges in variant assessment and validating genes

BACKGROUND

The routine genetic analysis for diagnosing male infertility has not changed over the last twenty years, and currently available tests can only determine the etiology of 4% of unselected infertile patients. Thus, to create new diagnostic assays, we must better understand the molecular and genetic mechanisms of male infertility. Although next-generation sequencing allows for simultaneous analysis of hundreds of genes and the discovery of novel candidates related to male infertility, so far only a few gene candidates have enough sound evidence to support the gene-disease relationship.

OBJECTIVE

Since complementary studies are required to validate genes, we aimed to analyze the presence of potentially pathogenic rare variants in a set of candidate genes related to azoospermia in a hitherto understudied South American population.

SUBJECTS AND METHODS

We performed whole exome sequencing in a group of 16 patients with non-obstructive azoospermia from Ribeirão Preto, Brazil. Based on a recent systematic review of monogenic causes of male infertility, we selected a set of 37 genes related to azoospermia, Sertoli-Cell-Only histology, and spermatogenic arrest to analyze. The identified variants were confirmed by Sanger sequencing, and their functional consequence was predicted by in silico programs.

RESULTS

We identified potential pathogenic variants in seven genes in six patients. Two variants, c.671A>G (p.(Asn224Ser)) in DMRT1 and c.91C>T (p.(Arg31Cys)) in REC8, have already been described in association with azoospermia. We also found new variants in genes that already have moderate evidence of being linked to spermatogenic failure (TEX15, KLHL10), in genes with limited evidence (DNMT3B, TEX14) and in one novel promising candidate gene that has no evidence so far (SYCE1L).

DISCUSSION

Although this study included a small number of patients, the process of rationally selecting genes allowed us to detect rare potentially pathogenic variants, providing supporting evidence for validating candidate genes associated with azoospermia.

Case of Inherited Partial AZFa Deletion without Impact on Male Fertility

Male factor infertility accounts for 40–50% of all infertility cases. Deletions of one or more AZF region parts in chromosome Y are one of the most common genetic causes of male infertility. Usually full or partial AZF deletions, including genes involved in spermatogenesis, are associated with spermatogenic failure. Here we report a case of a Caucasian man with partial AZFa region deletion from a couple with secondary infertility. Partial AZFa deletion, involving part of USP9Y gene appears to be benign, as we proved transmission from father to son. According to our results, it is recommended to revise guidelines on markers selected for testing of AZFa region deletion, to be more selective against DDX3Y gene and exclude probably benign microdeletions involving only USP9Y gene.

Chromosomal and Y-chromosome microdeletion analysis in 1,300 infertile males and the fertility outcome of patients with AZFc microdeletions

The present study investigated the frequency of chromosome aberrations and AZF microdeletions in infertile patients with nonobstructive azoospermia (NOA) or severe oligozoospermia. Additionally, the effect of the AZFc microdeletions on the success of microdissection testicular sperm extraction (microTESE) and intracytoplasmic sperm injection (ICSI) methods were evaluated. Peripheral blood samples were received from 1,300 infertile men with NOA and severe oligozoospermia. Karyotyping and FISH analysis were performed according to standard methods. AZF microdeletions were analysed using multiplex polymerase chain reaction or GML Y-chromosome Microdeletion Detection System consisting of 14 markers. The chromosomal aberrations and the AZF microdeletions frequency among 1,300 infertile men were 10.6% and 4.0% respectively. Either ejaculated spermatozoa or microTESE was performed on only in 19 out of 26 patients with AZFc deletions. Of the 19 patients, four had severe oligozoospermia and 15 had NOA. In eight out of 15 NOA patients, testicular mature spermatozoa were obtained (53.3%) and then ICSI was applied to mature oocytes. After undergoing ICSI treatment, clinical pregnancy and live birth outcome rates were found to be 37.5% and 25% respectively. These results suggest that infertile patients with AZFc microdeletion could achieve successful fertilisation pregnancies with the help of assisted reproductive technology.

Obstetric and perinatal outcomes of intracytoplasmic sperm injection for infertile men with Y chromosome microdeletions

BACKGROUND

To evaluate the safety of intracytoplasmic sperm injection (ICSI) for men with Y chromosome azoospermia factor (AZF) microdeletions.

METHODS

Twenty-five men with Y chromosome microdeletions and their partners underwent ICSI treatment. These subjects were matched against 50 ICSI cycles in which the patients had normal Y chromosomes.

RESULTS

Among the 25 couples, 17 achieved a clinical pregnancy of which 14 continued to a live birth. Sixteen men had deletions of AZFc markers (sY152, sY254, and sY255), 1 had a deletion of sY152, 3 had a deletion of sY254, sY255, 1 had a deletion of sY152, sY239, Sy242, sY254, and sY255, and 3 had deletions of sY152, sY254, sY255, and sY157. AZFb microdeletions (sY127, sY134, and sY143) were found in 1 patient. AZF microdeletions had no adverse effects on the clinical pregnancy, implantation or delivery rates, birth weight, gestational age, or sex ratio when compared with the control group. Overall, the multiple gestation and preterm delivery rates of the AZF microdeletion group were similar to those in the control group.

CONCLUSION

Men with AZF microdeletions can achieve the delivery of healthy children using ICSI. In this series, it produced good implantation rate and obstetric and perinatal outcomes.