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

EAA/EMQN best practice guidelines for molecular diagnosis of Y-chromosomal microdeletions: State of the art 2023

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

Azoospermia factor c microdeletions and outcomes of assisted reproductive technology: a systematic review and meta-analysis

OBJECTIVE

To investigate whether Azoospermia Factor c (AZFc) microdeletions affect Assisted Reproductive Technology (ART) outcomes.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENTS

Infertile men with and without AZFc microdeletions.

INTERVENTION(S)

Electronic databases were searched for case-control studies reporting sperm retrieval rates and outcomes of ART in infertile men with and without AZFc microdeletions from inception to April 2023. Study quality was assessed using the Newcastle-Ottawa Scale. Summary effect sizes (odds ratio [OR] with 95% confidence interval [CI]) were calculated for both categories of infertile men.

MAIN OUTCOME MEASURES

The primary outcome was successful sperm retrieval and the secondary outcomes were outcomes of ART.

RESULTS

Case-control studies reporting sperm retrieval rates and ART outcomes in men with AZFa and AZFb deletions were unavailable. On the basis of the data from 3,807 men, sperm retrieval rates were found to be higher in men with AZFc microdeletions compared to their non-deleted counterparts [OR = 1.82, 95% CI 0.97, 3.41], but the difference was not statistically significant. A significantly lower fertilization rate (OR = 0.61, 95% CI [0.50, 0.74]), clinical pregnancy rate (OR = 0.61, 95% CI [0.42, 0.89]), and live birth rate (OR = 0.54, 95% CI [0.40, 0.72]) were observed in men with AZFc deletions compared with men without deletions. There was no statistically significant difference in rates of embryo cleavage, blastocyst formation, good-quality embryos, implantation, and miscarriage between the two groups. On correcting for female factors, the fertilization rate (OR = 0.76, 95% CI [0.71, 0.82]), cleavage rate (OR = 0.54, 95% CI [0.41, 0.72]), clinical pregnancy rate (OR = 0.39, 95% CI [0.30, 0.52]), and live birth rate (OR = 0.48, 95% CI [0.35, 0.65]) were significantly lower in men with AZFc deletions compared with controls.

CONCLUSIONS

Presence of AZFc microdeletions adversely affects outcomes of ART in infertile men. Further in-depth studies delineating the role of the AZF genes in embryonic development are necessary to understand the full-impact of this finding.

CLINICAL TRIAL REGISTRATION NUMBER

CRD42022311738.

An analysis of Y-chromosome microdeletion in infertile Korean men with severe oligozoospermia or azoospermia

PURPOSE

Infertility affects 10% to 15% of couples, and male factor accounts for 50% of the cases. The relevant male genetic factors, which account for at least 15% of male infertility, include Y-chromosome microdeletions. We investigated clinical data and patterns of Y-chromosome microdeletions in Korean infertile men.

MATERIALS AND METHODS

A total of 919 infertile men whose sperm concentration was ≤5 million/mL in two consecutive analyses were investigated for Y-chromosome microdeletion. Among them, 130 infertile men (14.1%) demonstrated Y-chromosome microdeletions. Medical records were retrospectively reviewed.

RESULTS

In 130 men with Y-chromosome microdeletions, 90 (69.2%) had azoospermia and 40 (30.8%) had severe oligozoospermia. The most frequent microdeletions were in the azoospermia factor (AZF) c region (77/130, 59.2%), followed by the AZFb+c (30/130, 23.1%), AZFa (8/130, 6.2%), AZFb (7/130, 5.4%), AZFa+b+c (7/130, 5.4%), and AZFa+c (1/130, 0.7%) regions. In men with oligozoospermia, 37 (92.5%) had AZFc microdeletion. Chromosomal abnormalities were detected in 30 patients (23.1%). Higher follicle-stimulating hormone level (23.2±13.5 IU/L vs. 15.1±9.0 IU/L, p<0.001), higher luteinizing hormone level (9.7±4.6 IU/L vs. 6.0±2.2 IU/L, p<0.001), and lower testis volume (10.6±4.8 mL vs. 13.3±3.8 mL, p<0.001) were observed in azoospermia patients compared to severe oligozoospermia patients.

CONCLUSIONS

Y-chromosome microdeletion is a common genetic cause of male infertility. Therefore, Y-chromosome microdeletion test is recommended for the accurate diagnosis of men with azoospermia or severe oligozoospermia. Appropriate genetic counseling is mandatory before the use of assisted reproduction technique in men with Y-chromosome microdeletion.

From Diagnosis to Treatment: Comprehensive Care by Reproductive Urologists in Assisted Reproductive Technology

Infertility is a global health concern, with male factors playing an especially large role. Unfortunately, however, the contributions made by reproductive urologists in managing male infertility under assisted reproductive technology (ART) often go undervalued. This narrative review highlights the important role played by reproductive urologists in diagnosing and treating male infertility as well as any barriers they face when providing services. This manuscript presents a comprehensive review of reproductive urologists' role in managing male infertility, outlining their expertise in diagnosing and managing male infertility as well as reversible causes and performing surgical techniques such as sperm retrieval. This manuscript investigates the barriers limiting urologist involvement such as limited availability, awareness among healthcare professionals, and financial constraints. This study highlights a decrease in male fertility due to lifestyle factors like sedentary behavior, obesity, and substance abuse. It stresses the significance of conducting an evaluation process involving both male and female partners to identify any underlying factors contributing to infertility and to identify patients who do not require any interventions beyond ART. We conclude that engaging urologists more effectively in infertility management is key to optimizing fertility outcomes among couples undergoing assisted reproductive technology treatments and requires greater education among healthcare providers regarding the role urologists and lifestyle factors that could have an effect on male fertility.

STK33 phosphorylates fibrous sheath protein AKAP3/4 to regulate sperm flagella assembly in spermiogenesis

Spermatogenesis defects are important for male infertility; however, the etiology and pathogenesis are still unknown. Herein, we identified two loss of function mutations of STK33 in 7 individuals with non-obstructive azoospermia. Further functional studies of these frameshift and nonsense mutations revealed that Stk33^-/KI male mice were sterile, and Stk33^-/KI sperm were abnormal with defects in the mitochondrial sheath (MS), fibrous sheath (FS), outer dense fiber (ODF) and axoneme. Stk33^KI/KI male mice were subfertile and had oligoasthenozoospermia. Differential phosphoproteomic analysis and in vitro kinase assay identified novel phosphorylation substrates of STK33, fibrous sheath components AKAP3 and AKAP4, whose expression levels decreased in testis after deletion of Stk33. STK33 regulated the phosphorylation of AKAP3/4, affected the assembly of fibrous sheath in the sperm, and played an essential role in spermiogenesis and male infertility.

[AZF gene microdeletions in azoospermic-oligozoospermic males]

BACKGROUND AND OBJECTIVE

The presence of microdeletions in the Y-chromosome azoospermia factor (AZF) region (YCMs) is considered the most frequent genetic cause of male infertility along with Klinefelter syndrome. The objective of this study was to investigate the frequencies and type of YCMs in infertile men in Aragon and to analyze the relationship between sex hormones, sperm count and microdeletions in them.

PATIENTS AND METHODS

Retrospective descriptive study of 644 men who during 2006-2019 were screened for YCMs using YChromStrip (Operón, Spain) by PCR+reverse hybridization, spermiogram, karyotype and quantification of sex hormones.

RESULTS

The frequency of YCMs was 3.88% (25/644), not being detected in any patient with mild or normospermic oligozoospermia, that is, in sperm counts higher than 5×10⁶/mL. The group of azoospermic patients was the one that presented a higher frequency of YCMs (14.58%, 14/96). Deletions in the AZFc region were the most frequent (68%). 20% (5/25) of patients with YCMs also presented some type of karyotype abnormality that included aneuploidies, deletions, duplications and/or translocations. Sperm count was significantly lower and FSH and LH concentrations significantly higher in the group of patients with YCMs.

CONCLUSIONS

YCMs screening is a key test in the diagnostic approach to male infertility. Obtaining an adequate result allows choosing suitable assisted reproduction techniques, preventing unnecessary treatments and the transmission of genetic defects to offspring.

Male fertility as a marker for health

Male reproduction is a complex biological process, and male factor infertility is increasingly recognized as a biomarker for overall male health. Emerging data suggest associations between male reproduction and medical disease (genetic, infectious, chronic comorbid conditions), psychological disease, environmental exposures, dietary habits, medications and substances of abuse, and even socioeconomic factors. There is also evidence that a diagnosis of male fertility is associated with future disease risk including cancer, metabolic disease and mortality. As such, there is a growing view that the male fertility evaluation is an opportunity to improve a man's health beyond his immediate reproductive goals, and also highlights the necessity of a multidisciplinary approach.

Karyotypic abnormalities and Y chromosome microdeletions: How do these impact in vitro fertilization outcomes, and how common are they in the modern in vitro fertilization practice?

Objective

To examine the outcomes of in vitro fertilization with intracytoplasmic sperm injection (IVF-ICSI) in couples in whom the male partner has a karyotypic abnormality or Y chromosome microdeletion (YCM).

Design

Retrospective cohort.

Setting

Single infertility center.

Patient(s)

Couples treated with IVF-ICSI from January 2014 to April 2019 with male factor infertility, sperm concentration of <5 × 10⁶ sperm/mL, and results for karyotype and/or YCM panel.

Intervention(s)

In vitro fertilization with intracytoplasmic sperm injection.

Main Outcome Measure(s)

In couples in whom the male partner had a karyotypic abnormality or YCM: live birth rate/ongoing pregnancy rate, lack of partner sperm for fertilization, complete fertilization failure, cycle cancellation, and no embryos for transfer. The prevalence of karyotypic abnormalities and YCMs in the IVF population was calculated.

Result(s)

The live birth rate/ongoing pregnancy rate for those using partner sperm was 51.4% per transfer. However, 8.5% of cycles that intended to use partner sperm and 22.2% of cycles that intended to use surgically extracted partner sperm had no sperm available. Of cycles that created embryos with partner sperm, 12.5% had no embryo to transfer. The prevalence of karyotypic abnormalities was similar to previous reports (6.0%), while that of YCMs was lower (4.4%). Azoospermia factor a and b mutations were not represented in this population.

Conclusion(s)

It is reasonable to attempt IVF-ICSI with partner sperm in patients with genetic causes of male infertility. Patients should be counseled regarding the possibility of no sperm being available from the male partner, poor/failed fertilization, and genetic implications for potential offspring. Contingency plans, including IVF with donor sperm backup or oocyte cryopreservation, need to be made for these scenarios.

European Association of Urology Guidelines on Male Sexual and Reproductive Health: 2021 Update on Male Infertility

CONTEXT

The European Association of Urology (EAU) has updated its guidelines on sexual and reproductive health for 2021.

OBJECTIVE

To present a summary of the 2021 version of the EAU guidelines on sexual and reproductive health, including advances and areas of controversy in male infertility.

EVIDENCE ACQUISITION

The panel performed a comprehensive literature review of novel data up to January 2021. The guidelines were updated and a strength rating for each recommendation was included that was based either on a systematic review of the literature or consensus opinion from the expert panel, where applicable.

EVIDENCE SYNTHESIS

The male partner in infertile couples should undergo a comprehensive urological assessment to identify and treat any modifiable risk factors causing fertility impairment. Infertile men are at a higher risk of harbouring and developing other diseases including malignancy and cardiovascular disease and should be screened for potential modifiable risk factors, such as hypogonadism. Sperm DNA fragmentation testing has emerged as a novel biomarker that can identify infertile men and provide information on the outcomes from assisted reproductive techniques. The role of hormone stimulation therapy in hypergonadotropic hypogonadal or eugonadal patients is controversial and is not recommended outside of clinical trials. Furthermore, there is insufficient evidence to support the widespread use of other empirical treatments and surgical interventions in clinical practice (such as antioxidants and surgical sperm retrieval in men without azoospermia). There is low-quality evidence to support the routine use of testicular fine-needle mapping as an alternative diagnostic and predictive tool before testicular sperm extraction (TESE) in men with nonobstructive azoospermia (NOA), and either conventional or microdissection TESE remains the surgical modality of choice for men with NOA.

CONCLUSIONS

All infertile men should undergo a comprehensive urological assessment to identify and treat any modifiable risk factors. Increasing data indicate that infertile men are at higher risk of cardiovascular mortality and of developing cancers and should be screened and counselled accordingly. There is low-quality evidence supporting the use of empirical treatments and interventions currently used in clinical practice; the efficacy of these therapies needs to be validated in large-scale randomised controlled trials.

PATIENT SUMMARY

Approximately 50% of infertility will be due to problems with the male partner. Therefore, all infertile men should be assessed by a specialist with the expertise to not only help optimise their fertility but also because they are at higher risk of developing cardiovascular disease and cancer long term and therefore require appropriate counselling and management. There are many treatments and interventions for male infertility that have not been validated in high-quality studies and caution should be applied to their use in routine clinical practice.

Detection and analysis of null alleles of amelogenin in gender identification

In this study, we located eight samples with null alleles of amelogenin out of 10,750 cases, and discussed the influence in gender identification and forensic personal identification. Amelogenin was detected and retested by several autosomal STR kits and sex chromosomal STR kits, and the causes were analyzed by chromosome karyotype analysis and Y chromosome microdeletion detection if necessary. Suspected AMEL-X loss was observed in five samples, but no abnormality was detected in the X-STR loci. AMEL-X was recovered when samples were retested by other detection systems designed with different primers. One sample had AMEL-X and X-STR loci loss, and the karyotype was chimeric 45,X0[70]/46,X,+mar[13].Two male samples lost AMEL-Y fragment, and both of them lost DYS522-DYS570-DYS576 loci, but no abnormalities were found in the STS loci of SRY and AZF regions. Therefore, when carrying out gender identification by using amelogenin, it is essential to focus on null alleles of amelogenin. In especially, deal with the samples collected from the individuals who had chromosomal hereditary disorders(e.g. Turner Syndrome and Oligospermia / Azoospermia). In order to achieve this, laboratories should have various techniques to verify the null alleles of amelogenin and ensure accurate genotyping. Accurate genotyping of amelogenin and DNA database establishment are vital for personal identification.

Male infertility due to testicular disorders

CONTEXT

Male infertility is defined as the inability to conceive following 1 year of regular unprotected intercourse. It is the causative factor in 50% of couples and a leading indication for assisted reproductive techniques (ART). Testicular failure is the most common cause of male infertility, yet the least studied to date.

EVIDENCE ACQUISITION

The review is an evidence-based summary of male infertility due to testicular failure with a focus on etiology, clinical assessment, and current management approaches. PubMed-searched articles and relevant clinical guidelines were reviewed in detail.

EVIDENCE SYNTHESIS/RESULTS

Spermatogenesis is under multiple levels of regulation and novel molecular diagnostic tests of sperm function (reactive oxidative species and DNA fragmentation) have since been developed, and albeit currently remain as research tools. Several genetic, environmental, and lifestyle factors provoking testicular failure have been elucidated during the last decade; nevertheless, 40% of cases are idiopathic, with novel monogenic genes linked in the etiopathogenesis. Microsurgical testicular sperm extraction (micro-TESE) and hormonal stimulation with gonadotropins, selective estrogen receptor modulators, and aromatase inhibitors are recently developed therapeutic approaches for men with the most severe form of testicular failure, nonobstructive azoospermia. However, high-quality clinical trials data is currently lacking.

CONCLUSIONS

Male infertility due to testicular failure has traditionally been viewed as unmodifiable. In the absence of effective pharmacological therapies, delivery of lifestyle advice is a potentially important treatment option. Future research efforts are needed to determine unidentified factors causative in "idiopathic" male infertility and long-term follow-up studies of babies conceived through ART.

Effect of Y Chromosome Microdeletions on the Pregnancy Outcome of Assisted Reproduction Technology: a Meta-analysis

This systematic analysis aimed to summarize the effects of Y chromosome microdeletions (YCMs) on pregnancy outcomes of assisted reproductive technology (ART). This retrospective controlled meta-analysis evaluated the effect of YCMs on pregnancy outcomes of ART. Full-text retrieval was conducted in the PubMed, CBM, Web of Science, CNKI, VIP, and WANFANG databases. The pregnancy outcomes included fertilization rate, good embryo rate, clinical pregnancy rate, early miscarriage rate, miscarriage rate, live birth rate, and baby boy rate. The quality of these studies was evaluated using the Newcastle-Ottawa scale. Statistical software Review Manager 5.3 and STATA 14.0 were used. Twelve high-quality studies were included in the analysis. Compared with that in the normal group, the fertilization rate in the YCMs group decreased significantly (odds ratio [OR] = 0.75, 95% confidence interval [CI] [0.63, 0.88], P = 0.0006). However, there was no significant difference (P > 0.05) between groups in the good embryo rate (OR = 0.88, 95% CI [0.72, 1.07]), clinical pregnancy rate (OR = 0.94, 95% CI [0.78, 1.11]), early miscarriage rate (OR = 1.70, 95% CI [0.93, 3.10]), miscarriage rate (OR = 1.3, 95% CI [0.93, 1.91]), live birth rate (OR = 0.90, 95% CI [0.74, 1.08]), and baby boy rate (OR = 1.15, 95% CI [0.85, 1.56]). YCMs are associated with a reduced fertilization rate of ART, but they do not decrease the good embryo rate, clinical pregnancy rate, early miscarriage rate, miscarriage rate, live birth rate, or baby boy rate.

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.

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.

Multiscale analysis of SRY-positive 46,XX testicular disorder of sex development: Presentation of nine cases

46,XX testicular disorder of sex development (46,XX TDSD) is a relatively rare condition characterised by the presence of testicular tissue with 46,XX karyotype. The present study aims to reveal the phenotype to genotype correlation in a series of sex-determining region Y (SRY)-positive 46,XX TDSD cases. We present the clinical findings, hormone profiles and genetic test results of six patients with SRY-positive 46,XX TDSD and give the details and follow-up findings of our three of previously published patients. All patients presented common characteristics such as azoospermia, hypergonadotropic hypogonadism and an SRY gene translocated on the terminal part of the short arm of one of the X chromosomes. Mean ± standard deviation (SD) height of the patients was 164.78 ± 8.0 cm. Five patients had decreased secondary sexual characteristics, and three patients had gynaecomastia with varying degrees. Five of the seven patients revealed a translocation between protein kinase X (PRKX) and inverted protein kinase Y (PRKY) genes, and the remaining two patients showed a translocation between the pseudoautosomal region 1 (PAR1) of X chromosome and the differential region of Y chromosome. X chromosome inactivation (XCI) analysis results demonstrated random and skewed XCI in 5 cases and 1 case, respectively. In brief, we delineate the phenotypic spectrum of patients with SRY-positive 46,XX TDSD and the underlying mechanisms of Xp;Yp translocations.

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.

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.

New insights to guide patient care: the bidirectional relationship between male infertility and male health

Male reproduction is a complex process, and numerous medical conditions have the potential to alter spermatogenesis. In addition, male factor infertility may be a biomarker for future health. In the present review, we discuss the current literature regarding the association between systemic diseases and fertility, which may impact clinical outcomes or semen parameters. A number of conditions that have systemic consequences were identified, including genetic (e.g., cystic fibrosis, DNA mismatch repair alterations), obesity, psychological stress, exogenous testosterone, and a variety of common medications. As such, the infertility evaluation may offer an opportunity for health counseling beyond the discussion of reproductive goals. Moreover, male infertility has been suggested as a marker of future health, given that poor semen parameters and a diagnosis of male infertility are associated with an increased risk of hypogonadism, cardiometabolic disease, cancer, and even mortality. Therefore, male fertility requires multidisciplinary expertise for evaluation, treatment, and counseling.