Male Fertility · Male Endocrine and Genetic Factors
Impact of FSHB and FSHR Genes Polymorphisms on Hormonal Profile and Sperm Retrieval Outcome in Men With Klinefelter Syndrome: A Clinical-Genetic Predictive Study
Genetic variability within the follicle-stimulating hormone (FSH)-related genes might contribute to phenotypic heterogeneity in patients with Klinefelter syndrome (KS), yet its clinical impact on sperm retrieval remains unclear.
Objectives
To investigate the association between FSHB c.211 G > T and FSHR polymorphisms (c.2039 A > G and c.29 G > A) and hormonal parameters, as well as their potential role in predicting sperm retrieval rate (SRR) in patients with KS undergoing testicular sperm extraction (TESE).
Materials and Methods
A retrospective cohort of patients with KS was analyzed. Only subjects not receiving testosterone replacement therapy were included (n = 417). Hormonal, anthropometric, and clinical variables were compared across genotypes using nonparametric tests. Additive genetic models were applied to evaluate allele-dose effects. Multivariable logistic regression was performed to identify independent predictors of SRR. Predictive performance of clinical and combined clinical-genetic models was assessed using ROC curve analysis.
Results
FSHB and FSHR genes polymorphisms were associated with variations in serum FSH concentrations, confirming a modulatory role of the FSH-related genes. In additive modeling, the FSHR c.29 G > A polymorphism emerged as an independent predictor of SRR (adjusted OR: 0.29; 95% CI, 0.09-0.97), whereas FSHB c.211 G > T showed a nonsignificant trend. The inclusion of genetic variants modestly improved predictive accuracy compared with clinical variables alone, as demonstrated by ROC analysis.
Discussion and Conclusions
Genetic variants within the genes involved in FSH action might contribute incremental information for the prediction of sperm retrieval in patients with KS. While the overall predictive gain remains moderate, additive genetic modeling highlights a potential allele-dose effect of FSHR c.29 G > A on reproductive outcome, supporting a role for integrated clinical-genetic assessment in this population, although external validation remains required.
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.
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.
Ponce MR et al., 2026·Andrology·Free full text on PubMed Central
Transgender individuals assigned male at birth (AMAB) may choose to preserve their fertility prior to starting gender-affirming hormone therapy (GAHT). However, limited data exist regarding the baseline reproductive and hormonal characteristics of this population before and after GAHT.
To characterize semen quality and hormonal profiles in transgender AMAB individuals prior to GAHT and compare findings with cisgender men and with transgender individuals who discontinued GAHT for at least 3 months.
This retrospective study included transgender AMAB individuals from two tertiary andrology centers who underwent sperm cryopreservation before GAHT initiation (treatment-naïve group). Clinical evaluation included anthropometric measures, testicular volume assessment, varicocele detection, and sex hormone measures. Semen parameters were analyzed according to WHO criteria and compared with those of cisgender men and previously treated transgender individuals.
Thirty-two treatment-naïve transgender AMAB individuals were included. Hormonal parameters were generally within reference ranges. Only 46.9% of treatment-naïve individuals met WHO criteria for normozoospermia, compared with 75.5% of cisgender controls. Compared with nine previously treated individuals, estradiol levels were higher and seminal volume lower. A higher frequency of seminal abnormalities was observed, although not statistically significant.
A substantial proportion of treatment-naïve transgender AMAB individuals exhibited impaired semen parameters prior to GAHT initiation. Prior GAHT exposure showed a trend toward poorer semen quality. These findings support early fertility counseling and preservation in transgender individuals prior to GAHT initiation.
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
To investigate whether sperm recovery is related to clinical features, hormone parameters and testosterone replacement therapy (TRT) in patients with Klinefelter syndrome (KS).
This study provides three interesting insights: (i) the probability to retrieve sperm is not related to testicular volume; (ii) TRT does not affect sperm retrieval rate (SRR); and (iii) reduced levels of LH and FSH represent a negative predictor of sperm retrieval in patients with TRT.
Classical KS shows a karyotype with one extra X chromosome in all of somatic cells and clinical manifestations characterized by hypergonadotropic hypogonadism and infertility.
STUDY DESIGN, We performed a retrospective cohort study. Data from 111 consecutive KS azoospermic patients undergoing testicular sperm extraction (TESE) were collected from 2005 to 2016.
PARTICIPANTS/MATERIALS, Data on anthropometric parameters, reproductive hormones and testicular volumes were collected. SRR was related to clinical characteristics and compared between TRT and untreated patients.
MAIN A total of 38 patients (34.2%) had successful sperm recovery. The comparison of clinical characteristics did not differ between patients with and without sperm recovery. Sperm retrieval was successful also in subjects with smaller testes. The comparison of SRR in patients with or without TRT was not different (33.3% vs 34.6%). In TRT group, LH and FSH levels were significantly lower in subjects with no sperm retrieval (P values, respectively, <.05 and <.001).
LIMITATIONS Well-designed controlled studies are necessary to confirm these data aimed to set the best therapeutic approach for fertility management in hypogonadal patients with nonmosaic KS.
Age at TESE, anthropometric measures, testis volume, sex hormones levels and semen parameters are not predictive parameters of SRR. Among TRT patients, reduced gonadotropin is related to failure in sperm retrieval.
Male Endocrine and Genetic Factors · Genetic Causes of Male Infertility
Pengo M et al., 2006·Reproductive biomedicine online
In women, single nucleotide polymorphisms (SNP) of the FSH receptor (FSHR) gene influence FSH concentrations and the sensitivity of the FSHR to FSH in vivo. In contrast, the significance of FSHR R gene SNP in the male is poorly understood. To this aim, the possible role of three FSHR SNP was evaluated in male infertility. SNP in exon 10 (codon 307 and 680) and in the core promoter region (at position -29) of the FSHR gene were analysed by polymerase chain reaction-restriction fragment length polymorphism technique in 150 men representative of the general population, 107 proven fathers, 92 normozoospermic controls, and 215 infertile patients classified according to sperm parameters (38 azoospermia, 53 severe oligozoospermia, 48 moderate oligozoospermia, and 76 slight oligozoospermia). Reproductive hormones were measured in infertile males and normozoospermic controls. No significant difference was found in allelic variants frequency and genotype distribution between each category of subjects when analysing the FSHR exon 10 SNP alone and in combination with the SNP at position -29. Serum FSH concentrations and other andrological parameters did not differ between subjects with different genotype within each group. The data showed that in the Italian population, FSHR genotypes have no influence on FSH concentrations both in normal and infertile males and do not associate with spermatogenetic impairment.
Male Endocrine and Genetic Factors · Genetic Causes of Male Infertility
Selice R et al., 2011·International journal of andrology
In the last years, follice-stimulating hormone (FSH) receptor (FSHR) gene polymorphisms have been studied as potential risk factors for spermatogenetic failure. In this study, we have evaluated the response of FSH treatment in terms of sperm production on the basis of Ala307Thr-Asn680Ser polymorphisms in the FSHR gene in a group of oligozoospermic subjects with hypospermatogenesis and normal FSH levels. Patients were randomized into two groups: 70 treated with recombinant FSH (150 IU thrice per week for 3months) and 35 without treatment. After 3months of treatment, we observed significant increase in total sperm count, sperm concentration, forward motility, percentage of normal morphology forms and total motile sperm. When 70 treated subjects were subdivided based on FSHR genotype, only subjects with at least one serine in position 680 showed a statistically significant increase in these sperm parameters, whereas subjects with homozygote Thr307-Asn680 showed no difference in any seminal parameters evaluated. Non-treated subjects showed no differences in any parameter evaluated. This study suggests that the analysis of this gene represents a valid pharmacogenetic approach to the treatment of male infertility, confirming also the importance of strict criteria for the selection of patients to be treated with FSH.
Male Endocrine and Genetic Factors · Genetic Causes of Male Infertility
To verify in another population (Italians) whether a single-nucleotide polymorphism in the FSHB gene promoter previously associated with serum FSH levels in Estonians is indeed associated with sperm count and FSH plasma levels, and especially to verify whether it could be a pharmacogenetic tool for the treatment of male infertility with FSH.
Cross-sectional and prospective study.
Infertility center at a university hospital.
PATIENT(S): Five hundred fourteen subjects with nonobstructive azoospermia and oligozoospermia and 248 subjects with normozoospermia.
INTERVENTION(S): None.
MAIN OUTCOME MEASURE(S): Semen parameters, reproductive hormone levels, and FSHB -211 G/T polymorphism (rs10835638).
RESULT(S): FSHB -211 TT genotype was associated with significantly lower FSH levels (mean ± SD: 3.3 ± 2.5 IU/L vs. 9.1 ± 8.9 IU/L in GG homozygotes). TT homozygotes were seen in 25% of subjects with azoo-oligozoospermia and low FSH levels (≤1.5 IU/L). We did not observe this genotype in men with high FSH levels (>8 IU/L) or in men with normozoospermia. Treatment with FSH induced a significantly higher improvement in sperm count and quality in TT homozygotes regarding carriers of the G allele.
CONCLUSION(S): FSHB -211 TT genotype might represent a novel treatable form of male infertility characterized by severe spermatogenic impairment and low or inappropriately normal FSH plasma levels. This genetic marker could represent a valid pharmacogenetic approach for identification of potential responders to FSH treatment.
Male Fertility › Male Endocrine and Genetic Factors › Genetic Causes of Male Infertility · Genetics and Immunology › Reproductive Genetics › Chromosomal Abnormalities
A Di Mambro
PMID 42157550 42157550 DOI 10.1111/andr.70262 10.1111/andr.70262 Graziani et al. 2026, Graziani 2026
