Male Fertility · Male Endocrine and Genetic Factors
Abstract
Purpose
To develop and assess a novel custom next-generation sequencing (NGS) panel for male infertility genetic diagnosis.
Methods
A total of 241 subjects with diagnosis of idiopathic infertility ranging from azoospermia to normozoospermia were sequenced by a custom NGS panel including AR, FSHB, FSHR, KLHL10, NR5A1, NANOS1, SEPT12, SYCP3, TEX11 genes. Variants with minor allele frequency < 1% were confirmed by Sanger sequencing.
Results
Nineteen missense variants were detected in 23 subjects with abnormal sperm count, whilst no variants were identified in normozoospermic men. Of identified variants, we prioritized variants classified as pathogenic and of uncertain significance (VUS) (63.1%, 12/19). No missense variants were found in males with normal seminal parameters (0/67). Therefore, the prevalence of variants was significantly higher in patients with spermatogenic impairment (16/174 vs 0/67, p = 0.007).
Conclusion
This study confirms the utility to apply NGS panel for infertility diagnosis in order to find new genetic variants potentially linked to male infertility with much higher accuracy than standard tests suggested by guidelines. Indeed, based on biological significance, prevalence in the general population and clinical data of patients, it is plausible that identified variants in this study might be linked to quantitative spermatogenic impairment, although further studies are needed.
Topics
By this author
Semen Analysis · Sperm Function Testing
Preimplantation genetic testing for male factor infertility: lights and shadows
Mazzilli R et al., 2026 · Journal of endocrinological investigation
Male factor could contribute, alone or in combination with female factor, to the inability to conceive in a couple in more than half of cases. The effect of male factor infertility (MFI) on embryological assisted reproductive technology (ART) outcomes remains an ongoing discussion. to evaluate the impact of MFI on embryo aneuploidy rates, to better understand the role and possible indication for Preimplantation genetic testing for aneuploidies (PGT-A), considering the role of sperm characteristics, paternal age, sperm DNA fragmentation and sperm aneuploidies. this narrative review included all available articles, published up to January 2026. Available evidence, often based on heterogeneous and old-fashioned methodologies, suggests that MFI may impair embryonic development, particularly in terms of fertilization rate and blastulation rate, more than embryo euploidy; however, a comprehensive evaluation of MFI should be integrated into clinical practice in the context of couple infertility, to also optimize the efficiency and outcomes of ART. Promising results emerged from sperm DNA fragmentation as a tool to predict embryo euploidy, but further investigations involving larger sample sizes and improved standardization are required.
Male Factor Causes · Hormonal Causes
Pathophysiology-Based Classification of Male Infertility: Evidence from an 800-patient Prospective Cohort
Grande G et al., 2026 · The Journal of clinical endocrinology and metabolism · Free to read
Male factor infertility (MFI) is frequently labelled idiopathic when evaluation relies primarily on semen analysis, potentially overlooking endocrine and pathophysiological mechanisms relevant for targeted management. To phenotypically define MFI and develop a pathophysiology-based classification aimed at reducing idiopathic infertility following comprehensive evaluation. Prospective monocentric cohort study conducted at a tertiary referral academic centre. Eight hundred male partners of infertile couples evaluated between October 2024 and January 2026 after exclusion of isolated female factor infertility. Prevalence of MFI categories, hormonal patterns across phenotypes, and proportion of idiopathic infertility after comprehensive work-up. All patients underwent standardized clinical evaluation, hormonal assessment (total testosterone, FSH, LH), testicular ultrasound, and complete semen analysis. Microbiological testing, transrectal ultrasound, and genetic analyses were performed according to guidelines. Primary spermatogenic failure was the most prevalent category (56.0%), followed by infection/inflammation (22.4%) and hypogonadotropic hypogonadism (8.5%). Idiopathic infertility was identified in only 5.3% of cases. Distinct endocrine profiles were observed, with high-FSH spermatogenic failure representing the dominant phenotype. Comprehensive phenotyping markedly reduces the proportion of patients classified as having idiopathic infertility and identifies clinically relevant subgroups. This prospective study provides validation of a pathophysiology-based classification and supports a shift toward endocrine-integrated diagnostic strategies in male infertility, with potential implications for targeted management.
Semen Analysis · Sperm Function Testing
Beyond semen analysis: in men with normal semen parameters telomere attrition and oxidative imbalance distinguish those fertile from those with infertility
Rocca MS et al., 2026 · Journal of translational medicine · Free to read
Standard semen analysis has little prognostic value in distinguishing fertile from infertile men. Furthermore, in men with semen parameters within the reference ranges, it cannot distinguish fertile men from infertile men, i.e. partners of couples with idiopathic infertility. Oxidative stress, mitochondrial dysfunction, sperm telomere shortening, and DNA fragmentation have been proposed as contributors to impaired male fertility. However, these biomarkers have not been evaluated as a whole in subjects with normal semen parameters, partners of fertile and infertile couples. To characterise a multidimensional panel of sperm biomarkers-including sperm telomere length (STL), mitochondrial DNA copy number (mtDNAcn), reactive oxygen species (ROS), lipid peroxidation (LP), sperm chromatin dispersion (SCD), and respiratory control ratio (RCR)-and to identify whether these parameters might discriminate, in men with normal semen parameters, infertile men from fertile controls. A total of 150 men with semen parameters within the normal ranges were enrolled: 47 male partners of couples with idiopathic infertility and 103 fertile controls. STL and mtDNAcn were quantified by qPCR; ROS were assessed using OxiSperm®II with semiquantitative imaging; LP was measured spectrophotometrically in seminal plasma; SCD was used to determine DNA fragmentation; and mitochondrial function was evaluated by oxygen consumption and RCR. Correlations between biomarkers and semen parameters were analysed using Pearson or Spearman coefficients, and intergroup comparisons were adjusted for age. Semen parameters did not differ significantly between male partners of fertile and infertile couples. compared to men of fertile couples, men of infertile couples exhibited significantly shorter STL (0.57 ± 0.59 vs 1.21 ± 1.13, p_adj = 0.001) and higher oxidative stress, with both ROS (8300.9 ± 4214.8 vs 6555.3 ± 3394.3, p_adj = 0.027) and LP (88.33 ± 55.50 vs 40.29 ± 46.98, p_adj < 0.001) markedly elevated. mtDNAcn, SCD, and RCR showed no difference between the groups. Across the entire cohort, STL correlated negatively with ROS and LP and positively with RCR. ROS correlated negatively with total sperm count, motility and RCR, and positively with LP. LP displayed the strongest pattern of associations, correlating negatively with concentration, total count, motility, STL and RCR, and positively with age and volume. Among men with normal semen analysis, partners of couples with idiopathic infertility exhibit a distinct sperm molecular profile characterised by telomere shortening and oxidative imbalance. STL, ROS and LP emerged as age-independent biomarkers associated with infertility status and showed promising discriminatory ability in this cohort, supporting their integration as second-level tests to complement routine semen analysis in cases of normozoospermia.
Neoplastic Risk in Patients With Klinefelter Syndrome
Graziani A et al., 2026 · Andrology · Free to read
Besides gonadal involvement (hypogonadism, male factor infertility, and testicular hypotrophy), patients with Klinefelter syndrome (KS) may suffer from several extra-gonadic complications, including neoplastic events. The aim of this review is to summarize all major clinical evidence dealing with the association between KS and neoplastic diseases and provide practical suggestions for the management of patients with KS regarding neoplastic risk. This narrative review was conducted through a comprehensive search of the PubMed database, using combinations of the following keywords: "Klinefelter syndrome," "cancer," "neoplasm," "breast cancer," "germ cell tumor," "lymphoma," and "testosterone replacement therapy". KS is associated with a higher risk of breast cancer and mediastinal germ cell tumors and an apparent higher risk of hematological malignancies, in particular non-Hodgkin lymphoma and leukemia. Evidence on testicular cancer is limited, with no clear increase in risk attributable to KS, while prostate cancer has a lower risk and lower mortality rate. Given the complexity of the syndrome and the limited available evidence, regular clinical follow-up with targeted investigations when clinically indicated may facilitate early diagnosis and management of associated comorbidities.
Related research
Male Endocrine and Genetic Factors · Genetic Causes of Male Infertility
New genetic markers for male infertility
Ferlin A et al., 2014 · Current opinion in obstetrics & gynecology
The purpose of this review is to highlight the most important advances in the field of genetics of male infertility, with particular attention to primary articles dealing with the identification of new genetic and epigenetic markers that could be translated into clinical practice in the near future. Copy number variations (CNVs) of the Y chromosome (gr/gr) deletions could already be included in the diagnostic workup of infertile men, although confirming studies are needed for CNVs on the X chromosome, as well for polymorphisms in some autosomal genes and telomere length in sperm. Methods need to be further standardized before sperm DNA analysis could be included in clinical practice, although they can help in defining some forms of idiopathic infertility. Epigenetic biomarkers are potentially important in elucidating the cause of idiopathic male infertility. Polymorphisms in FSHB/FSHR could be used in clinical practice to diagnose some forms of male infertility and as a pharmacogenetic marker for FSH treatment. New genetic causes and genetic risk factors have been identified in recent years and new technologies for genomic and postgenomic analyses (arrays, next-generation sequencing, proteomics, metabolomics, global methylome analysis and so on) are promising research fields. It is presumed that some of these genetic and epigenetic tests will be introduced in clinical practice in the near future.
Male Endocrine and Genetic Factors · Genetic Causes of Male Infertility
Molecular and clinical characterization of Y chromosome microdeletions in infertile men: a 10-year experience in Italy
Ferlin A et al., 2007 · The Journal of clinical endocrinology and metabolism
An explosive growth in Y chromosome long arm (Yq) microdeletion testing demand for male infertility occurred in the past few years. However, despite the progresses in the biology of this chromosome, a number of molecular and clinical concerns are not supported by definitive data. The objective was to provide information on the type and prevalence of microdeletions in infertile males, indication for testing, genotype-phenotype correlation, sperm aneuploidies, and genetic counseling. We performed a prospective study from January 1996 to December 2005 in an academic clinic. We studied 3073 consecutive infertile men, of which 625 were affected by nonobstructive azoospermia and 1372 were affected by severe oligozoospermia. Ninety-nine patients with microdeletions are described here. Yq microdeletions, seminal analysis, reproductive hormones, testicular cytology/histology, and sperm sex chromosomes aneuploidies were used as outcome measures. The prevalence of microdeletions was 3.2% in unselected infertile men, 8.3% in men with nonobstructive azoospermia, and 5.5% in men with severe oligozoospermia. Only 2 of 99 deletions were found in men with more than 2 million sperm/ml. No clinical data are useful to identify a priori patients with higher risk of Yq microdeletions. Most deletions are of the AZFc-b2/b4 subtype and are associated with variable spermatogenic phenotype, with sperm present in 72% of the cases. Complete AZFa and AZFb (P5/Proximal P1) deletions are associated with Sertoli cell-only syndrome and alterations in spermatocyte maturation, respectively, whereas partial deletions in these regions are associated with milder phenotype and frequent presence of sperm. Men with AZFc-b2/b4 deletions produce a higher percentage of sperm with nullisomy for the sex chromosomes and XY-disomy. This extensive clinical research expands the knowledge on genotype-phenotype relationships and confirms that the identification of Yq microdeletions has significant diagnostic and prognostic value, adding useful information for genetic counseling in these patients.
Male Endocrine and Genetic Factors · Genetic Causes of Male Infertility
Genetic abnormalities among severely oligospermic men who are candidates for intracytoplasmic sperm injection
Foresta C et al., 2005 · The Journal of clinical endocrinology and metabolism
Recent reports suggest that children born after intracytoplasmic sperm injection performed for male factor infertility are at increased risk of congenital malformations and chromosome aberrations. To explain these observations, we hypothesized that infertile men may be more likely than fertile men to have genetic abnormalities. We studied 750 severely oligozoospermic men (sperm count <5 million/ml) who were candidates for intracytoplasmic sperm injection, and 303 fertile men. We analyzed the peripheral blood karyotype, the Y chromosome long arm for detection of microdeletions in the azoospermia factors, and mutations in the cystic fibrosis gene and the androgen receptor gene. We also analyzed sperm for chromosome aneuploidies among the 421 men who subsequently entered the in vitro fertilization program. A total of 104 genetic abnormalities were diagnosed, corresponding to a frequency of 13.9% (104 of 750). Chromosomal aberrations were present in 5.6% (42 of 750) of infertile men and 0.3% of controls (one of 295), and they were in most cases alterations of the sex chromosomes. Y chromosome long-arm microdeletions were detected in 6.0% (45 of 750) of infertile men and most frequently included the azoospermia factor c, whereas no cases were found in controls (zero of 210). Mutations in the cystic fibrosis gene were diagnosed in 1.2% (nine of 750) of infertile men and 1.0% of controls (three of 303), and mutations in the androgen receptor gene were found in 1.1% (eight of 750) of infertile men and none of the 188 controls. Sperm sex chromosome aneuploidies were increased in men with karyotype anomalies and Y chromosome microdeletions as well as in subjects without constitutional genetic abnormalities. This study shows that the frequency of genetic alterations is increased among men with severe spermatogenic impairment. Genetic tests and genetic counseling should therefore be considered in oligozoospermic men who are candidates for intracytoplasmic sperm injection.
Male Endocrine and Genetic Factors · Genetic Causes of Male Infertility
The Genetics of Infertility: Current Status of the Field
Zorrilla M et al., 2014 · Curr Genet Med Rep · Free full text on PubMed Central
Infertility is a relatively common health condition, affecting nearly 7% of all couples. Clinically, it is a highly heterogeneous pathology with a complex etiology that includes environmental and genetic factors. It has been estimated that nearly 50% of infertility cases are due to genetic defects. Hundreds of studies with animal knockout models convincingly showed infertility to be caused by gene defects, single or multiple. However, despite enormous efforts, progress in translating basic research findings into clinical studies has been challenging. The genetic causes remain unexplained for the vast majority of male or female infertility patients. A particular difficulty is the huge number of candidate genes to be studied; there are more than 2,300 genes expressed in the testis alone, and hundreds of those genes influence reproductive function in humans and could contribute to male infertility. At present, there are only a handful of genes or genetic defects that have been shown to cause, or to be strongly associated with, primary infertility. Yet, with completion of the human genome and progress in personalized medicine, the situation is rapidly changing. Indeed, there are 10-15 new gene tests, on average, being added to the clinical genetic testing list annually.
Male Fertility › Male Endocrine and Genetic Factors › Genetic Causes of Male Infertility · Genetics and Immunology › Reproductive Genetics › Single Gene Conditions
Aichi Msaki, Ilaria Cosci, Kalliopi Pilichou, Rudy Celeghin
A Msaki, I Cosci, K Pilichou, R Celeghin
PMID 32242295 32242295 DOI 10.1007/s10815-020-01747-0 10.1007/s10815-020-01747-0 Rocca et al. 2020, Rocca 2020