Clinical Management of Congenital Hypogonadotropic Hypogonadism

PROKR2 mutations and SPRY4 variants with uncertain significance in a Kallmann syndrome family: Incomplete penetrance

Kallmann syndrome is a rare genetic disease characterized by the idiopathic hypogonadotropic hypogonadism with hyposmia or anosmia, which exhibits considerable heterogeneity in genotype and phenotype. Herein, we reported a 32-year-old male patient with Kallmann syndrome in a family associated with heterozygous mutations in PROKR2 and SPRY4 genes. The genotyping results indicated PROKR2 mutations and SPRY4 variants of uncertain significance, which might be incompletely penetrant in this family.

Biological pathways leading to septo-optic dysplasia: a review

BACKGROUND

The precise etiology of septo-optic dysplasia (SOD) remains elusive, to date a complex interaction between genetic predisposition and prenatal exposure to environmental factors is believed to come into play. Being SOD such a heterogeneous condition, disruption of many developmental steps in the early forebrain development might occur. The knowledge of genes possibly determining SOD phenotype should be improved, therefore in this review the authors attempt to highlight the genetic pathways and genes related to this clinical condition.

MAIN BODY

Literature search was conducted and updated in November 2023, using PubMed and Google Scholar to identify primary research articles or case reports with available full text using the following search string "case reports," "humans," "septo-optic dysplasia," "optic nerve hypoplasia," with a recognized genetic diagnosis. Moreover, a review of genetic pathways with an involvement in SOD etiology was conducted. This review thus represents the authors' perspective based on selected literature. The several pathways presented might be already associated to other disease phenotypes and interplay with genes and pathways known to have a role in SOD determination. Those pathways may converge and thus, the implicated genes may function as cascading regulators at multiple levels.

CONCLUSION

The present data suggest that genes other than HESX1, SOX2, SOX3, and OTX2 might be investigated in candidate individuals with a clinical diagnosis of SOD corresponding to the presence of at least two diagnostic criteria, particularly in the presence of additional syndromic anomalies.

Androgen receptor CAG repeat polymorphism might be a possible cause of familial constitutional delay of growth and puberty

BACKGROUND

Induction of puberty in boys with constitutional delay of growth and puberty (CDGP) through a short course of low-dose testosterone therapy indicates the critical interaction between testosterone and the androgen receptor (AR) during the activation and maturation of the hypothalamic-pituitary-gonadal axis at puberty onset. Previous studies have shown an inverse relationship between the CAG repeat length and the transactivation function or expression level of the AR gene.

OBJECTIVE

We aimed to investigate whether the AR CAG repeat polymorphism has any implications on pubertal delay.

SUBJECTS AND METHODS

Thirty-three male patients with CDGP were enrolled in the study group, while 53 age-matched healthy individuals who had entered puberty on time were included in the control group. The CAG repeat length was determined through direct DNA sequencing analysis.

RESULTS

The median chronological age of boys with CDGP was 14.2 (14.1-14.6) years, compared to 14.2 (13.65-14.8) years for healthy subjects (p = 0.5). In the CDGP group, 22 (66.7%) children had a family history of the condition. There was no significant difference between the groups in terms of AR CAG repeat length (median AR CAG repeat length: 21 (20-24.5) and 20 (20-24), respectively, p = 0.1). However, in boys with CDGP with a similar family history (n = 22), a significantly longer AR CAG repeat length was found compared to the control group (n = 53) (median AR CAG repeat length: 22 (20-25) and 20 (20-24), respectively, p = 0.03). The median AR CAG repeat length in boys without a family history was 21 (20-22) triplets. Although boys with a family history had a slightly longer AR CAG repeat length than those without, the difference was not statistically significant (p = 0.07). Additionally, no significant differences were observed between boys with non-familial CDGP and control subjects (p = 0.8). Furthermore, no significant differences in anthropometric characteristics or hormonal parameters were found when patients with CDGP were categorized by AR CAG repeat length quartiles.

CONCLUSION

This is the first study to investigate the role of AR CAG polymorphism in the etiopathogenesis of CDGP. Our findings suggest that the AR CAG repeat length may be associated with familial CDGP.

Gonadotropic axis following endoscopic surgery for pituitary neuroendocrine tumor in patients of reproductive age

PURPOSE

Pituitary neuroendocrine tumor (PitNET), excluding prolactinoma, often requires endoscopic endonasal surgery (EES). Identifying predictive factors for complications, and particularly rare ones such as hypogonadotropic hypogonadism (HH) that may affect fertility, is challenging. This study investigated de-novo postoperative HH and its potential impact on fertility.

METHODS

We conducted a retrospective study of 211 patients undergoing EES. HH was evaluated using age- and gender-specific criteria. The characteristics of patients of reproductive age were analyzed to identify risk factors for de-novo postoperative HH.

RESULTS

Twelve of the 60 patients of reproductive age with no preoperative HH (20%) developed de-novo HH within 4-6months' follow-up, with 7 (12%) presenting long-term HH (median: 893 days). De-novo HH was significantly associated with corticotroph adenoma (P=0.01). Median tumor size was greater in HH than non-HH patients (P<0.01).

CONCLUSION

De-novo HH is a frequent complication of pituitary surgery, affecting 1 in 5 patients in our cohort, and is persistent in most cases. While risk factors such as large tumor size and corticotroph subtype were identified, the condition is still difficult to predict. These findings underscore the importance of integrating this risk into preoperative counseling and follow-up.

Body Composition, Adipocytokine, and Metabolic Parameters in Men With Congenital Hypogonadotropic Hypogonadism

OBJECTIVE

This study aimed to evaluate the long-term effects of hormone therapies on the body composition, adipokines and metabolic parameters of adult men with congenital hypogonadotropic hypogonadism (CHH).

METHODS

Sixty-six patients with CHH and 21 healthy controls were recruited. Patients were divided into untreated (n = 33) and treated (n = 33) groups based on hormone therapy history. Body composition was assessed using dual-energy X-ray absorptiometry (DXA), and adipokines and metabolic parameters were measured in all participants.

RESULTS

Compared to the healthy control group, patients in the treated group had lower serum testosterone levels (p < 0.001), increased body fat percentage (BFP) and visceral adipose tissue (VAT) volume, decreased lean soft tissue (LST) and bone mineral content (BMC) (p < 0.05), increased serum leptin levels accompanied by decreased adiponectin (ADP) (p < 0.05), higher HOMA-IR with lower QUICKI (p < 0.05). Compared to the untreated group, patients in the treated group (therapy duration 4.8 ± 2.3 years) had higher serum testosterone levels (p < 0.001), decreased BFP and VAT volume, increased LST and BMC (p < 0.05), decreased serum leptin levels (p < 0.001), and decreased HOMA-IR accompanied by increased QUICKI (p < 0.05). Among them, VAT volume, LST, BMC, HOMA-IR and QUICKI reached healthy control levels (p > 0.05). Multiple stepwise linear regression analysis showed serum testosterone levels were negatively correlated with BFP (β = -0.564, p < 0.001) and VAT volume (β = -0.260, p = 0.045), positively correlated with LST (β = 0.305, p = 0.018) and BMC (β = 0.423, p = 0.001). Serum testosterone levels were independently negatively correlated with leptin levels (β = -0.277, p = 0.004).

CONCLUSIONS

Patients with untreated CHH had impaired body composition, adipokines and metabolic parameters. While hormone therapies can improve body composition and glucolipid metabolism in patients with CHH, this imperfect treatment does not fully rescue body composition abnormalities when compared to healthy individuals. Abnormal metabolic parameters in patients with CHH are associated with increased fat mass and abnormal serum leptin level. Serum testosterone levels were independently negatively correlated with leptin levels.

Comparison of outcomes between pulsatile gonadotropin releasing hormone and combined gonadotropin therapy of spermatogenesis in patients with congenital hypogonadotropic hypogonadism

BACKGROUND

To evaluate whether there was a difference in outcome between pulsatile gonadotropin releasing hormone (GnRH) therapy and human chorionic gonadotropin/human menopausal gonadotropin (hCG/HMG) therapy for induction of spermatogenesis in post-pubertal male patients with congenital hypogonadotropic hypogonadism (CHH).

METHODS

This was a single-center retrospective cohort study conducted at the Andrology Center of a university hospital. A total of 155 postpubertal CHH patients who met the inclusion criteria underwent spermatogenic induction at the same andrology center. All patients used pulsatile GnRH therapy or hCG/HMG therapy for at least 6 months. The effects of spermatogenic induction therapy and testicular growth were evaluated. Logistic regression analysis was used to identify statistically significant factors which could predict the outcome of treatment.

RESULTS

There was no difference in the efficiency of successfully inducing spermatogenesis between pulsatile GnRH therapy and hCG/HMG therapy (82.1% vs. 75.8%, P: 0.356), nor was there a difference in sperm concentration category (SCC) (P: 0.284). However, the mean time required for pulsatile GnRH therapy was shorter (12.34 vs. 14.74 months, P: 0.038). At the treatment endpoint, total testicular volume (TTV) was greater with pulsatile GnRH therapy compared with hCG/HMG therapy (15 vs. 12 ml, P: 0.010), and there was still no difference in SCC (P: 0.310). Multivariate logistic regression analysis showed that only baseline TTV was statistically significant predictor of induced spermatogenic success (odds ratio, OR: 1.156, 95% confidence interval, CI: 1.013, 1.319). The area under receiver operating characteristic curve was 0.635, a sensitivity of 0.661, and a specificity of 0.588. In addition, multiple linear regression analysis demonstrated that younger age at treatment initiation and higher baseline TTV were significantly associated with increased sperm concentration at the end of treatment.

CONCLUSION

Pulsatile GnRH therapy was similar to hCG/HMG therapy in inducing spermatogenesis in post-pubertal CHH patients, but it took less time and was more beneficial to testicular development. Larger baseline TTV may mean a better spermatogenic outcome. It was necessary for patients to have more information about spermatogenesis therapy in order to make reasonable medical decisions.

CLINICAL TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry. ChiCTR2400086876. Retrospectively registered on July 5, 2024.

Clinical presentation of congenital hypogonadotropic hypogonadism in males with delayed puberty according to genetic etiology: a systematic review and meta-analysis after reclassification of gene variants

STUDY QUESTION

Which phenotypes can be confidently linked to a genetic etiology in males with congenital hypogonadotropic hypogonadism (CHH) resulting in absent or arrested puberty?

SUMMARY ANSWER

In this systematic review and reclassification of the disease-causing potential of gene variants using the recommendations of the American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP), we found that absent or arrested puberty in males with CHH was linked to 93 genes, of which 29 were unequivocally disease-causing.

WHAT IS KNOWN ALREADY

The number of genes and phenotype characterizations associated with CHH in males has rapidly increased since the advent of next-generation sequencing technologies; however, the quality of the evidence for the interpretation of the causal relationship of gene variants is limited due to the lack of systematic criteria applied to the assessment of the pathogenic potential of the variants.

STUDY DESIGN, SIZE, DURATION

We performed a systematic review of original articles indexed in PubMed until 5 October 2022 and using the search terms '(('hypogonadotropic hypogonadism' OR Kallmann) AND (sequencing OR mutation OR variant))' limited to 'Humans' and 'English'.

PARTICIPANTS/MATERIALS, SETTING, METHODS

After two investigators undertook the literature search independently, titles and abstracts of all records were reviewed by four of the authors to identify those articles to be included in the full-text review. Clinical data and the association with gene variants were extracted from males with delayed or arrested puberty due to CHH according to the article authors' criteria. Raw sequence variant information was used to reevaluate their pathogenic potential applying the ACMG/AMP guidelines for variant classification with InterVar. Subsequently, we considered the phenotype specificity criteria for sequence variant pathogenicity classification, based on curated genes associated with CHH, and classified patients into three categories: with monogenic disease-causing variants in genes associated with CHH, with variants in genes whose causality is unclear, and with variants that are not disease-causing.

MAIN RESULTS AND THE ROLE OF CHANCE

From a total of 1083 records, we included 245 publications with 775 male patients with CHH resulting in absent or arrested puberty, carrying 1001 variants in 93 genes. Gene variants were detected by Sanger sequencing in 61.8% of the cases and by next-generation sequencing (NGS) technologies in the rest. After variant reclassification of causality, 278 individuals were not considered to have a bona fide disease-causing gene variant, and 497 patients were reclassified as carrying at least one disease-causing variant associated with CHH. They carried 503 different disease-causing variants in 29 genes. Spontaneous puberty was absent in 85.5% and arrested in 14.5% of the 497 individuals with CHH carrying bona fide disease-causing variants. In males with absent puberty (complete hypogonadotrophic hypogonadism), FGFR1 and ANOS1 were the most frequently affected genes, accounting for 53.5% of the disease-causing variants. In males with incomplete spontaneous puberty (partial hypogonadotrophic hypogonadism), variants in FGFR1, NR0B1, and GNRHR were found in 70.3% of the cases. Micropenis, cryptorchidism and/or low testicular volume, considered 'red flags' for the diagnosis of CHH, were found in less than 30% of males, with cryptorchidism being more frequently observed in association with variants in FGFR1, ANOS1, KISS1R, SOX10, and GNRH1, and micropenis being more prevalent in patients with variants in TACR3, KISS1R, or GNRH1. Clinical manifestations in non-reproductive organs were found in 39.8% of the patients with bona fide disease-causing variants.

LIMITATIONS, REASONS FOR CAUTION

Because we included studies going back to the initial genetic reports of patients with CHH, results obtained by Sanger sequencing represent a significant proportion of the whole sample, which may be biased by the use of a candidate gene strategy. A subanalysis of cases studied by NGS modified the results only slightly.

WIDER IMPLICATIONS OF THE FINDINGS

This comprehensive synthesis will help clinicians in the guidance of reverse phenotyping once the precise genetic diagnosis is established, and researchers in the design of functional studies to clarify the role of specific sequence variants in the etiology of male CHH. A genetic etiology of CHH in males with absent or arrested puberty should be considered even in the absence of micropenis, cryptorchidism, and/or low testicular volume.

STUDY FUNDING/COMPETING INTEREST(S)

This work was partially funded by grants PICT I-A-2018-02972 of Fondo de Promoción Científica y Técnica (FONCYT), PICT A-CAT III2021-73 of Fondo Argentino Sectorial (FONARSEC) and Proyectos de Redes Federales de Alto Impacto 2023 #3 of Ministerio de Ciencia, Tecnología e Innovación, Argentina. Competing interests: None declared.

REGISTRATION NUMBER

None declared.

Regulatory Involvement of Kisspeptin in Energy Balance and Reproduction

The hypothalamic-pituitary-gonadal axis, which regulates steroidogenesis and germ cell formation, closely regulates the reproduction process. Nonetheless, other chemical mediators, such as kisspeptin, influence this axis. Kisspeptin is a hypothalamic neuropeptide that modulates the function of this axis and also plays a central role in energy balance. The present study reviews the impact and associated mechanisms of kisspeptin on male and female reproduction based on available evidence in the literature. Kisspeptin and its neurons exert anorexigenic activity, thus maintaining adequate energy balance for optimal reproductive function. Also, they stimulate the release of GnRH, resulting in the optimal performance of gonadal physiological processes viz. production of steroid sex hormones and germ cells. However, studies linking kisspeptin to reproduction are yet scanty. Hence, studies exploring the upstream and downstream signaling pathways activated by kisspeptin concerning reproduction in an attempt to better understand the associated mechanisms of the regulatory activities of kisspeptin on reproduction are recommended. In addition, potential factors that may modulate kisspeptin activities may be useful in the management of infertility and perhaps, in the development of contraceptives for those who do not intend to achieve conception.

Clinical Presentation of Congenital Hypopituitarism: Lessons From a Large Academic Centre

OBJECTIVE

Pituitary hormone deficiencies are associated with considerable morbidity, yet the variability of presentation and evolution of congenital hypopituitarism remains unexplored. This study investigated differences in presentation of congenital isolated pituitary hormone deficiency (cIPHD) versus congenital multiple pituitary hormone deficiency (cMPHD) and the progression of cIPHD to multiple deficiencies.

DESIGN/PATIENTS/MEASUREMENTS

We conducted a single centre retrospective chart review of children ≤ 3 years old with abnormal brain/pituitary imaging and ≥ 1 pituitary hormone deficiency. cIPHD was defined as 1 hormone deficiency diagnosed within 1 month of endocrine consultation; cMPHD was ≥ 2 deficiencies. Data were summarised by descriptive statistics; Wilcoxon tests (continuous variables) and chi-square or Fisher's exact tests (categorical variables) were used for comparisons with significance at p < 0.05.

RESULTS

Fifty-six individuals were identified; 46.4% presented with cIPHD and 53.6% with cMPHD. Those with cIPHD were older at initial endocrine consultation (median 62.5 days [IQR 7.3-240.8]) vs. those with cMPHD (10.0 days [6.3-26.5], p = 0.02). Reason for consultation (e.g., abnormal imaging or hypoglycemia) was associated with presentation as cIPHD or cMPHD (p = 0.01). The most common cIPHD at presentation was AVP deficiency (34.6%); the most common cMPHD at presentation was combined ACTH and TSH deficiencies (43.3%). Most individuals with cIPHD (65.4%) progressed to multiple hormone deficiencies by 3 years of age.

CONCLUSIONS

Individuals with cMPHD were more likely to be identified earlier and present with hypoglycemia than those with cIPHD. As the majority with cIPHD evolved to cMPHD, close monitoring is necessary to facilitate timely detection and treatment of evolving hormone deficiencies.

Efficacy of Gonadotropin Treatment for Induction of Spermatogenesis in Men With Pathologic Gonadotropin Deficiency: A Meta-Analysis

INTRODUCTION

Hypogonadotropic hypogonadism (HH) is a treatable cause of nonobstructive azoospermic male infertility. Gonadotropin treatment can successfully induce spermatogenesis in most patients, although comprehensive quantitative summary data on spermatogenic outcomes like those required to induce pregnancy is lacking in the literature.

MATERIALS AND METHODS

Systematic review and meta-analysis of outcomes related to male reproductive function following gonadotropin treatment.

RESULTS

Our search strategy identified 41 studies encompassing 1673 patients with a mean age of 25 (± 5) years. Average sperm concentration achieved after a median of 18 months of gonadotropin treatment was 11.6 M/mL of ejaculate (95% CI 8.4-14.9). Sperm concentrations > 0, > 1, > 5, > 10 and > 20 M/mL were achieved by 78%, 55%, 36%, 24% and 15% of patients, respectively. Mean sperm output and the proportion of patients achieving all sperm thresholds were significantly greater following combined hCG/FSH treatment compared with hCG monotherapy. When compared by diagnosis, patients with congenital HH (CHH) had significantly lower mean sperm output compared with patients with hypopituitarism or mixed patient cohorts that did not differentiate between CHH and hypopituitarism. Treatment-related increases in testosterone and testicular volume (TV) were not different between hCG and combined hCG/FSH treated patients, although increases in TV were lower in men with CHH compared with those with hypopituitarism.

CONCLUSIONS

Gonadotropin treatment successfully induced spermatogenesis in most men with pathological gonadotropin deficiency. Sperm outputs more consistent with those typically needed to induce a natural pregnancy were less commonly achieved. Despite similar effects on serum testosterone and TV, combined hCG/FSH appeared more efficacious than hCG alone at inducing spermatogenesis.

Pulsatile gonadotropin-releasing hormone therapy: comparison of efficacy between functional hypothalamic amenorrhea and congenital hypogonadotropic hypogonadism

OBJECTIVE

To compare the ongoing pregnancy rate per initiated cycle between patients with functional hypothalamic amenorrhea (FHA) and patients with congenital hypogonadotropic hypogonadism (CHH) treated with pulsatile gonadotropin-releasing hormone (GnRH) administration.

DESIGN

Retrospective monocentric cohort study conducted at the University Hospital of Lille from 2004 to 2022.

SUBJECTS

A total of 141 patients diagnosed with central suprapituitary amenorrhea during infertility evaluation and subsequently treated with pulsatile GnRH therapy. 111 and 30 patients were diagnosed with FHA or CHH, respectively.

EXPOSURE

Pulsatile GnRH administration.

MAIN OUTCOME MEASURE(S)

Ongoing pregnancy rate per initiated cycle.

RESULT(S)

Ongoing pregnancy rates per initiated cycle were comparable between groups: 21.5% in the FHA group vs. 22% in the CHH group. Comparison of baseline characteristics showed a more pronounced follicle-stimulating hormone (FSH) deficiency in patients with CHH than in those with FHA: 2.55 (0.6-4.92) vs. 4.80 (3.90-5.70) UI/L. Within the CHH group, basal FSH level was positively associated with the occurrence of ongoing pregnancies (odds ratio, 1.57; 95% confidence interval, 1.11-2.22). In the CHH group, the duration of treatment was higher than in the FHA group: 23.59 (± 8.02) vs. 18.16 (± 7.66) days.

CONCLUSION(S)

The baseline FSH level is lower in patients with CHH than in patients with FHA. The lower the FSH, the lower the chance of pregnancy in patients with CHH. These patients also require more days of GnRH administration. However, the rate of ongoing pregnancies is comparable between the two groups.

Diagnosis and treatment of hypogonadism in men seeking to preserve fertility - what are the options?

Male hypogonadism is a clinical syndrome that results in low testosterone levels and frequently leads to infertility. The syndrome occurs due to disruption at one or more levels of the hypothalamic-pituitary-gonadal axis. Testosterone replacement therapy (TRT) is the most common treatment utilised for male hypogonadism. However, long-acting forms of TRT leads to infertility and so is inappropriate for patients wishing to conceive. For patients who wish to remain fertile, nasal TRT, clomiphene citrate, exogenous gonadotropins, gonadotropin releasing hormone and aromatase inhibitors have been used as alternative treatment options with different degrees of success. A review of the literature was performed to identify the safety and efficacy of alternative treatment options. Gonadotropin releasing hormone can successfully induce spermatogenesis but is impractical to administer. Likewise, aromatase inhibitors have limited use due to inducing osteopenia. Nasal TRT may be a good treatment option for these patients, but its efficacy has so far only been demonstrated in small sample sizes. However, clomiphene citrate and exogenous gonadotropins are safe, offer good symptom control and can successfully induce fertility in hypogonadism patients.

Evaluation of testicular volume in males with congenital hypogonadotropic hypogonadism: a comparative analysis

INTRODUCTION

Estimating accurate testicular volume (TV) of congenital hypogonadotropic hypogonadism (CHH) individuals is challenging due to the typically small testicular size. Ultrasound (USG) emerges as a vital solution, enabling precise measurements and reproducible results. The purpose of the study was to assess the three-dimensional measurement of the testis using USG and its volume was estimated using Ellipsoid (E) and Lambert (L) formulae and compared these with the TV by Prader orchidometer (OrTV).

METHODS

This is an exploratory analysis of data taken from a clinical trial conducted from May 2022 to March 2024 which included 94 testes from 47 CHH participants. The OrTVs and USGTVs were assessed at baseline and every three months till the completion of the study making a total of 348 observations. The three-dimensional measurement of the testes was noted and TVs were calculated using the above formulae.

RESULTS

The mean age of the participants was 25.8 ± 6.14 years with a mean height of 169.9 ± 8.42 cm and body mass index (BMI) of 22.4 ± 4.72 kg/m2. The baseline mean OrTV, USGTV(E) and USGTV(L) were 2.15 ± 0.79 ml, 0.69 ± 0.43 ml and 0.93 ± 0.59 ml respectively. The smallest OrTV observed was 1 ml with its respective mean USGTV of 0.41 ± 0.2 ml(E) and 0.56 ± 0.27 ml(L). An OrTV of 4 ml had a mean USGTV of 1.11 ± 0.42 ml(E) and 1.51 ± 9.57 ml(L). At spermatogenesis, the mean OrTV was 8.84 ± 3.13 ml with the USGTV determined to be 4 ± 1.46 ml(E) and 5.46 ± 1.99 ml(L).

CONCLUSION

The study revealed that all CHH patients at diagnosis had OrTV < 4 ml. This corresponds to a USG TV cut-off of 1.11 ml using the Ellipsoid formula and 1.51 ml with the Lambert formula, which could serve as a USG diagnostic criterion for CHH.

Kallmann syndrome: Diagnostics and management

Kallmann syndrome is a genetic disorder characterized by delayed or absence of puberty and a reduced or absent sense of smell (anosmia). Kallmann syndrome is a form of hypogonadotropic hypogonadism due to lack of the production of sex hormones which is associated with development of secondary sexual characteristics. Kallmann Syndrome is a genetically heterogeneous disorder, characterized by the combination of hypogonadotropic hypogonadism (a deficiency in sex hormone production) and anosmia. Germline mutations in KAL1 gene causes deficiency in GnRH hormone followed by low level of circulating gonadotropin and testosterone which finally leads to the failure of puberty (development of secondary sexual characters). Kallmann Syndrome can be inherited in several manners including X-linked recessive (e.g., mutations within KAL1) and autosomal dominant and recessive forms. Germline mutation in KAL1 gene was identified among 8% of patients with Kallmann Syndrome. A review of the recent literature done reveals numerous clinical manifestations in Kallmann Syndrome patients with the KAL1 mutation, including microgenitalia, impotence, reduced libido, infertility, unilateral renal agenesis, and synkinesia. Genetic molecular diagnostics through prenatal diagnosis and preimplantation genetic testing are most significant way to reduce the risk of Kallmann syndrome in next generation. Complication associated with Kallmann syndrome can be prevented by early diagnosis, diet supplementation and medical therapy. Goal of therapeutic intervention is to the development of secondary sexual characteristics, build and sustain bone density as well as muscle mass and restore fertility. This review aims to explore the genetic diagnosis and management strategies for Kallmann Syndrome, particularly focusing on KAL1 gene mutations.

Oral and Maxillofacial Manifestations of Kallmann Syndrome: A Systematic Analysis of the Literature

AIMS

Kallmann syndrome (KS) is a rare genetic disorder characterized by congenital hypogonadotropic hypogonadism and varied clinical features. Despite its recognition, the oral and maxillofacial manifestations remain poorly understood. This study synthesized clinical aspects and management of KS-related oral and maxillofacial alterations.

METHODS

Searches were conducted in the PubMed, Web of Science, Scopus, Embase, and LILACS databases, supplemented by manual scrutiny and gray literature. Case series and/or case reports were included. The Joanna Briggs Institute tool was employed for critical appraisal of the studies.

RESULTS

A total of 46 studies comprising 108 cases were included. The mean age of individuals was 19.8 (±12.6) years, and there was a marked predominance of males (79.3%). Cleft lip/palate (32.7%) was the predominant oral condition, followed by high-arched palate (21.7%), and dental agenesis (19.8%). Oral treatment consisted of corrective surgery of the cleft lip and/or palate (n = 9), myoplasty (n = 1), and tooth extraction/orthodontic treatment (n = 1). Hyposmia/anosmia (71.3%) was the most frequently reported manifestation.

CONCLUSION

Early diagnosis and interdisciplinary collaboration are essential for addressing the complex nature of KS-related oral and maxillofacial alterations and improving patient outcomes. The scarcity of data on oral treatment underscores the need for additional research and clinical attention in this field.

A Therapeutic Proposal for Mini-Puberty in Male Infants with Hypogonadotropic Hypogonadism: A Retrospective Case Series

Background: Male patients with congenital hypogonadotropic hypogonadism (CHH) have impaired postnatal activation of the hypothalamic-pituitary-gonadal axis that occurs during mini-puberty. The aim of this study was to report our experience using gonadotropin replacement therapy for mini-puberty in male infants with CHH and to establish treatment recommendations. Methods: The patients included in this retrospective case series (n = 9) were diagnosed in the postnatal period due to micropenis, with two being accompanied by cryptorchidism and four with other associated hormonal deficits. All patients started treatment with gonadotropins early after diagnosis, between 2 weeks and 5 months of age, with a schedule of discontinuous injections with subcutaneous human chorionic gonadotropin (62.5-500 IU) two times per week and recombinant follicle-stimulating hormone-alpha (37.5-75 IU) three times per week. Results: The data from our study show an early response, ranging from almost undetectable levels of testosterone at diagnosis to elevated levels after starting treatment, as well as a positive clinical response with increases in testicular volume and penis size in all cases without requiring complementary treatment with testosterone esters and without adverse effects. Conclusions: Our results show that gonadotropin replacement therapy is a well-tolerated and effective treatment for testicular and penile problems in male patients with CHH.

Kallmann Syndrome: Functional Analysis of a CHD7 Missense Variant Shows Aberrant RNA Splicing

Kallmann syndrome is a rare disorder characterized by hypogonadotropic hypogonadism and an impaired sense of smell (anosmia or hyposmia) caused by congenital defects in the development of the gonadotropin-releasing hormone (GnRH) and olfactory neurons. Mutations in several genes have been associated with Kallmann syndrome. However, genetic testing of this disorder often reveals variants of uncertain significance (VUS) that remain uninterpreted without experimental validation. The aim of this study was to analyze the functional consequences of a heterozygous missense VUS in the CHD7 gene (c.4354G>T, p.Val1452Leu), in a patient with Kallmann syndrome with reversal of hypogonadism. The variant, located in the first nucleotide of exon 19, was analyzed using minigene assays to determine its effect on ribonucleic acid (RNA) splicing. These showed that the variant generates two different transcripts: a full-length transcript with the missense change (p.Val1452Leu), and an abnormally spliced transcript lacking exon 19. The latter results in an in-frame deletion (p.Val1452_Lys1511del) that disrupts the helicase C-terminal domain of the CHD7 protein. The variant was reclassified as likely pathogenic. These findings demonstrate that missense variants can exert more extensive effects beyond simple amino acid substitutions and underscore the critical role of functional analyses in VUS reclassification and genetic diagnosis.

Disorders of puberty and neurodevelopment: A shared etiology?

The neuroendocrine control of puberty and reproduction is fascinatingly complex, with up- and down-regulation of key reproductive hormones during fetal, infantile, and later childhood periods that determine the correct function of the hypothalamic-pituitary-gonadal axis and the timing of puberty. Neuronal development is a vital element of these processes, and multiple conditions of disordered puberty and reproduction have their etiology in abnormal neuronal migration or function. Although there are numerous documented cases across multiple conditions wherein patients have both neurodevelopmental disorders and pubertal abnormalities, this has mostly been described ad hoc and the associations are not clearly documented. In this review, we aim to describe the overlap between these two groups of conditions and to increase awareness to ensure that puberty and reproductive function are carefully monitored in patients with neurodevelopmental conditions, and vice versa. Moreover, this commonality can be explored for clues about the disease mechanisms in these patient groups and provide new avenues for therapeutic interventions for affected individuals.

Fgf17: A regulator of the mid/hind brain boundary in mammals

The Fibroblast growth factor (FGFs) family consists of at least 22 members that exert their function by binding and activating fibroblast growth factor receptors (FGFRs). The Fgf8/FgfD subfamily member, Fgf17, is located on human chromosome 8p21.3 and mouse chromosome 14 D2. In humans, FGF17 can be alternatively spliced to produce two isoforms (FGF17a and b) whereas three isoforms are present in mice (Fgf17a, b, and c), however, only Fgf17a and Fgf17b produce functional proteins. Fgf17 is a secreted protein with a cleavable N-terminal signal peptide and contains two binding domains, namely a conserved core region and a heparin binding site. Fgf17 mRNA is expressed in a wide range of different tissues during development, including the rostral patterning centre, midbrain-hindbrain boundary, tailbud mesoderm, olfactory placode, mammary glands, and smooth muscle precursors of major arteries. Given its broad expression pattern during development, it is surprising that adult Fgf17-/- mice displayed a rather mild phenotype; such that mutants only exhibited morphological changes in the frontal cortex and mid/hind brain boundary and changes in certain social behaviours. In humans, FGF17 mutations are implicated in several diseases, including Congenital Hypogonadotropic Hypogonadism and Kallmann Syndrome. FGF17 mutations contribute to CHH/KS in 1.1% of affected individuals, often presenting in conjunction with mutations in other FGF pathway genes like FGFR1 and FLRT3. FGF17 mutations were also identified in patients diagnosed with Dandy-Walker malformation and Pituitary Stalk Interruption Syndrome, however, it remains unclear how FGF17 is implicated in these diseases. Altered FGF17 expression has been observed in several cancers, including prostate cancer, hematopoietic cancers (acute myeloid leukemia and acute lymphoblastic leukemia), glioblastomas, perineural invasion in cervical cancer, and renal cell carcinomas. Furthermore, FGF17 has demonstrated neuroprotective effects, particularly during ischemic stroke, and has been shown to improve cognitive function in ageing mice.

Society for endocrinology guideline for understanding, diagnosing and treating female hypogonadism

Female hypogonadism (FH) is a relatively common endocrine disorder in women of premenopausal age, but there are significant uncertainties and wide variation in its management. Most current guidelines are monospecialty and only address premature ovarian insufficiency (POI); some allude to management in very brief and general terms, and most rely upon the extrapolation of evidence from the studies relating to physiological estrogen deficiency in postmenopausal women. The Society for Endocrinology commissioned new guidance to provide all care providers with a multidisciplinary perspective on managing patients with all forms of FH. It has been compiled using expertise from Endocrinology, Primary Care, Gynaecology and Reproductive Health practices, with contributions from expert patients and a patient support group, to help clinicians best manage FH resulting from both POI and hypothalamo-pituitary disorders, whether organic or functional.

Pharmacological therapies for male infertility

Male factor infertility is a multifaceted problem that affects approximately 50% of couples suffering from infertility. Causes of male infertility include endocrine disturbances, gonadotoxins, genetic abnormalities, varicocele, malignancies, infections, congenital or acquired urogenital abnormalities, iatrogenic factors, immunological factors, and idiopathic reasons. There are a variety of treatment options for male infertility, depending on the underlying cause(s). These can include surgical treatments, medical/hormonal therapies, and assisted reproductive techniques (ART), which can be combined with surgical sperm retrieval (SSR) if necessary. In this review article, the pharmacological therapies for male infertility are grouped by their underlying causes. Some of these therapies are targeted and specific, while others are used empirically to treat idiopathic male infertility. This will include treatments to optimize infertility in patients who have hypogonadism, ejaculatory dysfunction, infections, or idiopathic male infertility. Finally, we will provide an overview of the future directions of pharmacological therapies for male infertility. Significance Statement Male infertility is a significant worldwide problem. Detailed knowledge of the pharmacological therapies available will ensure the prescription of appropriate therapy and avoid the use of unnecessary or harmful treatments.

An Update on Advances in Hypopituitarism: Etiology, Diagnosis, and Current Management

This article provides an updated review of hypopituitarism (HP), an endocrine disorder characterized by a deficiency of one or more pituitary hormones. The various etiologies are reviewed, including pituitary neuroendocrine tumors (PitNETs), hypothalamic lesions, genetic mutations, and acquired factors such as head trauma, medications, neoplasms, and infiltrative diseases. It is noted that PitNETs are responsible for approximately half of the cases in adults, whereas in children the causes are predominantly congenital. Diagnosis is based on clinical evaluation and hormonal testing, with identification of the specific hormonal deficiencies essential for effective treatment. Laboratory tests present challenges and limitations that must be understood and addressed. Hormone replacement therapy is the mainstay of treatment, significantly improving patients' quality of life. It is important to know the possible interactions between hormone replacement therapies in HP. Recent advances in understanding the pathophysiology of HP and the importance of a multidisciplinary approach to the management of associated complications are discussed. This article emphasizes the need for comprehensive evaluation and continuous follow-up to optimize outcomes in patients with HP and highlights the importance of ongoing research to improve diagnostic and treatment strategies.

Male hypogonadism: pathogenesis, diagnosis, and management

Organic male hypogonadism due to irreversible hypothalamic-pituitary-testicular (HPT) pathology is easily diagnosed and treated with testosterone-replacement therapy. However, controversy surrounds the global practice of prescribing testosterone to symptomatic men with low testosterone and non-gonadal factors reducing health status, such as obesity, type 2 diabetes, and ageing (ie, functional hypogonadism), but without identifiable HPT axis pathology. Health optimisation remains the gold-standard management strategy. Nevertheless, in the last decade large clinical trials and an individual patient data meta-analysis of smaller clinical trials confirmed that testosterone therapy induces modest, yet statistically significant, improvements in sexual function without increasing short-term to medium-term cardiovascular or prostate cancer risks in men with functional hypogonadism. Although testosterone improves bone mineral density and insulin sensitivity in these men, trials from the last decade suggest insufficient evidence to determine the safety and effectiveness of use of this hormone for the prevention of fractures or type 2 diabetes. This Review discusses the pathogenesis and diagnosis of male hypogonadism and appraises the evidence underpinning the management of this condition.

Effect of Combined Low Dose Human Gonadotropic Hormone, Follicle Stimulating Hormone, and Testosterone Therapy (LFT Regimen) Versus Conventional High Dose Human Gonadotropic Hormone and Follicle Stimulating Hormone on Spermatogenesis and Biomarkers in Men With Hypogonadotropic Hypogonadism

OBJECTIVE

In male congenital hypogonadotropic hypogonadism (CHH), it was observed that lower dose human gonadotropic hormone (hCG) can maintain normal intratesticular testosterone levels. We propose this study to compare the low-dose hCG, follicle stimulating hormone (FSH), and Testosterone (T) [LFT Regimen] to conventional treatment to induce virilization and fertility.

DESIGN

This open-label randomized pilot study was conducted from June 2020 to December 2021.

SUBJECTS AND OUTCOME MEASURES

CHH were randomly assigned to either the LFT regimen (Group A)-low-dose hCG (500U thrice per week), FSH (150U thrice per week), and T(100 mg biweekly) or conventional therapy(GroupB) with high hCG dose(2000U thrice per week) and the same FSH dose. The hCG dosage was titrated to reduce anti-mullerian hormone (AMH) by 50% and normalization of plasma T in groups A and B, respectively. The primary objective was to compare the percentage of individuals who achieved spermatogenesis between the two groups.

RESULTS

Out of 30 patients, 23 (76·7%) subjects achieved spermatogenesis, and the median time was 12 (9-14·9) months. There was no difference in achieving spermatogenesis between the two groups (64·3% vs 7·5%,P = 0·204), and even the median time for spermatogenesis was similar (15months vs 12months,P = 0·248). Both groups had nonsignificant median plasma AMH at spermatogenesis, [6·6 ng/ml (3·3-9·76) vs4·41 ng/ml (2·3-6·47), P = 0·298]. Similarly, the median plasma Inhibin B at spermatogenesis between groups were comparable [152·4 pg/ml (101·7-198·0) vs49·1 pg/ml (128·7-237·3), P = 0·488].

CONCLUSIONS

A reasonable approach to induce fertility in male CHH is to initiate combination therapy using FSH, low-dose hCG targeting AMH <6·9 ng/ml, along with T to achieve normal range. Monitoring AMH could serve as a proxy indicator of spermatogenesis.

Behavior, attitude, perception, and knowledge regarding fertility preservation among Chinese pediatric oncologists: a survey in China

PURPOSE

Clinical specialists are supposed to inform childhood cancer patients of infertility risk and conduct fertility preservation (FP). However, little is known about whether doctors in China are fully prepared. This study aimed to investigate behavior, attitude, perception, and knowledge regarding FP among pediatric oncological specialists in a nation wide survey, to set the stage for improvements in current clinical practice patterns.

METHODS

This study was conducted on physicians and surgeons specialized in pediatric oncology using a questionnaire through the WeChat platform. The behavior, attitude, perception, and knowledge were assessed by Likert questions and results were quantified to obtain scores. Data were then described and analyzed using R and GraphPad.

RESULTS

Totally 373 specialists in pediatric tumors were included in the analysis. Hematologists, oncological surgeons, and reproductive medicine specialists won most trusts to be responsible for FP job. Most respondents did not have habits of delivering FP information or cooperating with FP specialists during treatment though they were well equipped with FP knowledge and desired for uniform national guideline for FP procedures. The severity of illness was regarded as the primary barrier of FP delivery. When a doctor was more educated and experienced, he was more likely to have better performance in FP. The total score, the knowledge score, and the single score concerning frequency of patients' inquiry showed aggregational trend on geographic distribution.

CONCLUSION

Chinese pediatric oncologists demonstrated unsatisfactory practice behaviors based upon this self-reporting survey, although their attitude towards FP was generally positive.

Genetic architecture of congenital hypogonadotropic hypogonadism: insights from analysis of a Portuguese cohort

STUDY QUESTION

What is the contribution of genetic defects in Portuguese patients with congenital hypogonadotropic hypogonadism (CHH)?

SUMMARY ANSWER

Approximately one-third of patients with CHH were found to have a genetic cause for their disorder, with causal pathogenic and likely pathogenic germline variants distributed among 10 different genes; cases of oligogenic inheritance were also included.

WHAT IS KNOWN ALREADY

CHH is a rare and genetically heterogeneous disorder characterized by deficient production, secretion, or action of GnRH, LH, and FSH, resulting in delayed or absent puberty, and infertility.

STUDY DESIGN SIZE DURATION

Genetic screening was performed on a cohort of 81 Portuguese patients with CHH (36 with Kallmann syndrome and 45 with normosmic hypogonadotropic hypogonadism) and 263 unaffected controls.

PARTICIPANTS/MATERIALS SETTING METHODS

The genetic analysis was performed by whole-exome sequencing followed by the analysis of a virtual panel of 169 CHH-associated genes. The main outcome measures were non-synonymous rare sequence variants (population allele frequency <0.01) classified as pathogenic, likely pathogenic, and variants of uncertain significance (VUS).

MAIN RESULTS AND THE ROLE OF CHANCE

A genetic cause was identified in 29.6% of patients. Causal pathogenic and likely pathogenic variants were distributed among 10 of the analysed genes. The most frequently implicated genes were GNRHR, FGFR1, ANOS1, and CHD7. Oligogenicity for pathogenic and likely pathogenic variants was observed in 6.2% of patients. VUS and oligogenicity for VUS variants were observed in 85.2% and 54.3% of patients, respectively, but were not significantly different from that observed in controls.

LARGE SCALE DATA

N/A.

LIMITATIONS REASONS FOR CAUTION

The identification of a large number of VUS presents challenges in interpretation and these may require reclassification as more evidence becomes available. Non-coding and copy number variants were not studied. Functional studies of the variants were not undertaken.

WIDER IMPLICATIONS OF THE FINDINGS

This study highlights the genetic heterogeneity of CHH and identified several novel variants that expand the mutational spectrum of the disorder. A significant proportion of patients remained without a genetic diagnosis, suggesting the involvement of additional genetic, epigenetic, or environmental factors. The high frequency of VUS underscores the importance of cautious variant interpretation. These findings contribute to the understanding of the genetic architecture of CHH and emphasize the need for further studies to elucidate the underlying mechanisms and identify additional causes of CHH.

STUDY FUNDING/COMPETING INTERESTS

This research was funded by the Portuguese Foundation for Science and Technology (grant numbers PTDC/SAU-GMG/098419/2008, UIDB/00709/2020, CEECINST/00016/2021/CP2828/CT0002, and 2020.04924.BD) and by Sidra Medicine-a member of the Qatar Foundation (grant number SDR400038). The authors declare no competing interests.

Restoring function to inactivating G protein-coupled receptor variants in the hypothalamic-pituitary-gonadal axis1

G protein-coupled receptors (GPCRs) are central to the functioning of the hypothalamic-pituitary-gonadal axis (HPG axis) and include the rhodopsin-like GPCR family members, neurokinin 3 receptor, kappa-opioid receptor, kisspeptin 1 receptor, gonadotropin-releasing hormone receptor, and the gonadotropin receptors, luteinizing hormone/choriogonadotropin receptor and follicle-stimulating hormone receptor. Unsurprisingly, inactivating variants of these receptors have been implicated in a spectrum of reproductive phenotypes, including failure to undergo puberty, and infertility. Clinical induction of puberty in patients harbouring such variants is possible, but restoration of fertility is not always a realisable outcome, particularly for those patients suffering from primary hypogonadism. Thus, novel pharmaceuticals and/or a fundamental change in approach to treating these patients are required. The increasing wealth of data describing the effects of coding-region genetic variants on GPCR function has highlighted that the majority appear to be dysfunctional as a result of misfolding of the encoded receptor protein, which, in turn, results in impaired receptor trafficking through the secretory pathway to the cell surface. As such, these intracellularly retained receptors may be amenable to 'rescue' using a pharmacological chaperone (PC)-based approach. PCs are small, cell permeant molecules hypothesised to interact with misfolded intracellularly retained proteins, stabilising their folding and promoting their trafficking through the secretory pathway. In support of the use of this approach as a viable therapeutic option, it has been observed that many rescued variant GPCRs retain at least a degree of functionality when 'rescued' to the cell surface. In this review, we examine the GPCR PC research landscape, focussing on the rescue of inactivating variant GPCRs with important roles in the HPG axis, and describe what is known regarding the mechanisms by which PCs restore trafficking and function. We also discuss some of the merits and obstacles associated with taking this approach forward into a clinical setting.

Genome sequencing reveals novel causative structural and single nucleotide variants in Pakistani families with congenital hypogonadotropic hypogonadism

BACKGROUND/OBJECTIVES

This study aims to elucidate the genetic causes of congenital hypogonadotropic hypogonadism (CHH), a rare genetic disorder resulting in GnRH deficiency, in six families from Pakistan.

METHODS

Eighteen DNA samples from six families underwent genome sequencing followed by standard evaluation for pathogenic single nucleotide variants (SNVs) and small indels. All families were subsequently analyzed for pathogenic copy number variants (CNVs) using CoverageMaster.

RESULTS

Novel pathogenic homozygous SNVs in known CHH genes were identified in four families: two families with variants in GNRHR, and two others harboring KISS1R variants. Subsequent investigation of CNVs in the remaining two families identified novel unique large deletions in ANOS1.

CONCLUSION

A combined, systematic analysis of single nucleotide and CNVs helps to improve the diagnostic yield for variants in patients with CHH.

Evidence for NR2F2/COUP-TFII involvement in human testis development

NR2F2 encodes COUP-TFII, an orphan nuclear receptor required for the development of the steroidogenic lineages of the murine fetal testes and ovaries. Pathogenic variants in human NR2F2 are associated with testis formation in 46,XX individuals, however, the function of COUP-TFII in the human testis is unknown. We report a de novo heterozygous variant in NR2F2 (c.737G > A, p.Arg246His) in a 46,XY under-masculinized boy with primary hypogonadism. The variant, located within the ligand-binding domain, is predicted to be highly damaging. In vitro studies indicated that the mutation does not impact the stability or subcellular localization of the protein. NR5A1, a related nuclear receptor that is a key factor in gonad formation and function, is known to physically interact with COUP-TFII to regulate gene expression. The mutant protein did not affect the physical interaction with NR5A1. However, in-vitro assays demonstrated that the mutant protein significantly loses the inhibitory effect on NR5A1-mediated activation of both the LHB and INSL3 promoters. The data support a role for COUP-TFII in human testis formation. Although mutually antagonistic sets of genes are known to regulate testis and ovarian pathways, we extend the list of genes, that together with NR5A1 and WT1, are associated with both 46,XX and 46,XY DSD.

Mini-Puberty, Physiological and Disordered: Consequences, and Potential for Therapeutic Replacement

There are 3 physiological waves of central hypothalamic-pituitary-gonadal (HPG) axis activity over the lifetime. The first occurs during fetal life, the second-termed "mini-puberty"-in the first months after birth, and the third at puberty. After adolescence, the axis remains active all through adulthood. Congenital hypogonadotropic hypogonadism (CHH) is a rare genetic disorder characterized by a deficiency in hypothalamic gonadotropin-releasing hormone (GnRH) secretion or action. In cases of severe CHH, all 3 waves of GnRH pulsatility are absent. The absence of fetal HPG axis activation manifests in around 50% of male newborns with micropenis and/or undescended testes (cryptorchidism). In these boys, the lack of the mini-puberty phase accentuates testicular immaturity. This is characterized by a low number of Sertoli cells, which are important for future reproductive capacity. Thus, absent mini-puberty will have detrimental effects on later fertility in these males. The diagnosis of CHH is often missed in infants, and even if recognized, there is no consensus on optimal therapeutic management. Here we review physiological mini-puberty and consequences of central HPG axis disorders; provide a diagnostic approach to allow for early identification of these conditions; and review current treatment options for replacement of mini-puberty in male infants with CHH. There is evidence from small case series that replacement with gonadotropins to mimic "mini-puberty" in males could have beneficial outcomes not only regarding testis descent, but also normalization of testis and penile sizes. Moreover, such therapeutic replacement regimens in disordered mini-puberty could address both reproductive and nonreproductive implications.

Single and multi-dose pharmacology of recombinant and urinary human chorionic gonadotrophin in men

OBJECTIVE

Human choriogonadotrophin (hCG) treatment of gonadotrophin-deficient infertile men uses hCG of urinary (uhCG) or recombinant (rhCG) origin, but these treatments have not been compared nor are there studies defining rhCG dosing in men.

DESIGN

hCG products were studied in randomized cross-over single-dose studies of standard (Study 1, 1500 IU and 62.5 µg, respectively) or high (Study 2, 5000 IU and 250 µg) dose and a multi-dose population pharmacology study of hCG use.

PARTICIPANTS

Eight (Study 1) and seven (Study 2) volunteers in cross-over and 52 gonadotrophin-deficient men in the multi-dose study MEASUREMENTS: In cross-over studies, serum testosterone (T), dihydrotestosterone (DHT) and estradiol by liquid chromatography-mass spectrometry (LCMS) and serum hCG, LH, FSH, SHBG and T (observational study) by immunoassays.

RESULTS

After standard and high-dose injection, serum hCG and testosterone responses had similar timing and peak concentrations except for a mildly lower early (<48 h) serum testosterone with uhCG. In the multi-dosing study, both hCGs had similar pharmacokinetics (pooled half-life 5.8 days, p < .001), while serum testosterone concentrations were stable after injection and did not differ between hCG products. Bench testing verified that 20% of pens from 4/10 individuals were used inappropriately.

CONCLUSIONS

Although hCG pharmacokinetics are not formally bioequivalent, the similar pharmacodynamic effects on serum testosterone indicate that at the doses tested both hCGs provide comparable clinical effects. The starting dose of rhCG for treating gonadotrophin-deficient men should be 62.5 µg (6 clicks) of the rhCG pen.

Clinical manifestations and spermatogenesis outcomes in Chinese patients with congenital hypogonadotropic hypogonadism caused by inherited or de novo FGFR1 mutations

Fibroblast growth factor receptor 1 ( FGFR1 ) mutations are associated with congenital hypogonadotropic hypogonadism (CHH) through inheritance or spontaneous occurrence. We detected FGFR1 mutations in a Chinese cohort of 210 CHH patients at Peking Union Medical College Hospital (Beijing, China) using next-generation and Sanger sequencing. We assessed missense variant pathogenicity using six bioinformatics tools and compared clinical features and treatment outcomes between inherited and de novo mutation groups. Among 19 patients with FGFR1 mutations, three were recurrent, and 16 were novel variants. Sixteen of the novel mutations were likely pathogenic according to the American College of Medical Genetics and Genomics (ACMG) guidelines, with the prevalent P366L variant. The majority of FGFR1 mutations was inherited (57.9%), with frameshift mutations exclusive to the de novo mutation group. The inherited mutation group had a lower incidence of cryptorchidism, short stature, and skeletal deformities. In the inherited mutation group, luteinizing hormone (LH) levels were 0.5 IU l -1 , follicle-stimulating hormone (FSH) levels were 1.0 IU l -1 , and testosterone levels were 1.3 nmol l -1 . In contrast, the de novo group had LH levels of 0.2 IU l -1 , FSH levels of 0.5 IU l -1 , and testosterone levels of 0.9 nmol l -1 , indicating milder hypothalamus-pituitary-gonadal axis (HPGA) functional deficiency in the inherited group. The inherited mutation group showed a tendency toward higher spermatogenesis rates. In conclusion, this study underscores the predominance of inherited FGFR1 mutations and their association with milder HPGA dysfunction compared to de novo mutations, contributing to our understanding of the genetic and clinical aspects of FGFR1 mutations.

Position statement on the diagnosis and management of congenital pituitary deficiency in adults: The French National Diagnosis and Treatment Protocol (NDTP)

Pituitary deficiency, or hypopituitarism, is a rare chronic disease. It is defined by insufficient synthesis of one or more pituitary hormones (growth hormone, TSH, ACTH, LH-FSH, prolactin), whether or not associated with arginine vasopressin deficiency (formerly known as diabetes insipidus). In adult patients, it is usually acquired (notably during childhood), but can also be congenital, due to abnormal pituitary development. The present study focuses on congenital pituitary deficiency in adults, from diagnosis to follow-up, including special situations such as pregnancy or the elderly. The clinical presentation is highly variable, ranging from isolated deficit to multiple deficits, which may be part of a syndromic form or not. Diagnosis is based on a combination of clinical, biological (assessment of all hormonal axes), radiological (brain and hypothalamic-pituitary MRI) and genetic factors. Treatment consists in hormonal replacement therapy, adapted according to the period of life and the deficits, which may be progressive. Comorbidities, risk of complications and acute decompensation, and the impact on fertility and quality of life all require adaptative multidisciplinary care and long-term monitoring.

Gonadotropic status in adult women with pituitary stalk interruption syndrome

OBJECTIVE

Pituitary stalk interruption syndrome (PSIS) is a rare cause of congenital hypopituitarism. Limited data exist on the gonadotropic status and fertility of adult women with PSIS. Our study aims to describe pubertal development and the evolution of gonadotropic function and fertility in adult women with PSIS.

DESIGN

A retrospective multicentric French study.

METHODS

We described gonadotropic function in 56 adult women with PSIS from puberty onward. We compared live birth rates per woman with PSIS with age-matched controls from the large French epidemiological cohort (CONSTANCES). Additionally, we assessed height, body mass index (BMI), blood pressure, other metabolic parameters, and socioeconomic status.

RESULTS AND CONCLUSIONS

Among 56 women with PSIS, 36 did not experience spontaneous puberty. Of these, 13 underwent ovarian stimulation, resulting in 7 women having a total of 11 children. In the subgroup with spontaneous puberty (n = 20), 4 had a total of 8 pregnancies, while 6 developed secondary gonadotropic deficiency. Women with PSIS had fewer children than controls (0.33 vs 0.63, P = .04). Median height was also lower (160.5 vs 165.0 cm, P < .0001). Although mean blood pressure was lower in women with PSIS compared with controls (111.3/65.9 ± 11.2/8.1 vs 118.7/72.1 ± 10.1/7.7 mmHg, P < .001), there were no significant differences in other metabolic parameters, notably BMI and lipid profile. Employment/academic status was not different in the 2 groups, but fewer women with PSIS were in relationships (42% vs 57.6% in controls, P = .02). The fertility prognosis in patients with PSIS needs optimization. Patients should be informed about the likelihood of declining gonadotropic function over time.

Hormone Therapy During Infancy or Early Childhood for Patients with Hypogonadotropic Hypogonadism, Klinefelter or Turner Syndrome: Has the Time Come?

Managing patients unable to produce sex steroids using gonadotropins to mimic minipuberty in hypogonadotropic hypogonadism, or sex steroids in patients with Klinefelter or Turner syndrome, is promising. There is a need to pursue research in this area, with large prospective cohorts and long-term data before these treatments can be routinely considered.

Elevated chorionic gonadotropic hormone in transgenic mice induces parthenogenetic activation and ovarian teratomas

Both male and female reproductive functions are impacted by altered gonadotrophin secretion and action, which may also influence the development of endocrine tumours. To ascertain if chronic hypersecretion of human chorionic gonadotropin (hCG) contributes to the development of gonadal tumours, double transgenic (TG) mice that overexpress hCGα- and β-subunits were analysed. By the age of two months, ovarian tumours with characteristics of teratomas developed with 100% penetrance. Teratomas were also seen in wild-type ovaries orthotopically transplanted into TG mice, demonstrating an endocrine/paracrine mechanism for the hCG-induced ovarian tumorigenesis. Both in vitro and in vivo experiments showed oocyte parthenogenetic activation in TG females. In addition, ovaries showed reduced ovulatory gene expression, inhibited ERK1/2 phosphorylation, and impaired cumulus cell expansion. Hence, persistently high endocrine hCG activity causes parthenogenetic activation and development of ovarian teratomas, along with altered follicle development and impaired ERK1/2 signalling, offering a novel mechanism associated with the molecular pathogenesis of ovarian teratomas.

Hypogonadotropic Hypogonadism

Delayed puberty is defined as absent testicular enlargement in boys or breast development in girls at an age that is 2 to 2.5 SDS later than the mean age at which these events occur in the population (traditionally, 14 years in boys and 13 years in girls). One cause of delayed/absent puberty is hypogonadotropic hypogonadism (HH), which refers to inadequate hypothalamic/pituitary function leading to deficient production of sex steroids in males and females. Individuals with HH typically have normal gonads, and thus HH differs from hypergonadotropic hypogonadism, which is associated with primary gonadal insufficiency.

Hormone Regulation in Testicular Development and Function

The testes serve as the primary source of androgens and the site of spermatogenesis, with their development and function governed by hormonal actions via endocrine and paracrine pathways. Male fertility hinges on the availability of testosterone, a cornerstone of spermatogenesis, while follicle-stimulating hormone (FSH) signaling is indispensable for the proliferation, differentiation, and proper functioning of Sertoli and germ cells. This review covers the research on how androgens, FSH, and other hormones support processes crucial for male fertility in the testis and reproductive tract. These hormones are regulated by the hypothalamic-pituitary-gonad (HPG) axis, which is either quiescent or activated at different stages of the life course, and the regulation of the axis is crucial for the development and normal function of the male reproductive system. Hormonal imbalances, whether due to genetic predispositions or environmental influences, leading to hypogonadism or hypergonadism, can precipitate reproductive disorders. Investigating the regulatory network and molecular mechanisms involved in testicular development and spermatogenesis is instrumental in developing new therapeutic methods, drugs, and male hormonal contraceptives.

Pulsatile gonadotropin releasing hormone therapy for spermatogenesis in congenital hypogonadotropic hypogonadism patients who had poor response to combined gonadotropin therapy

Objective

Both pulsatile gonadotropin-releasing hormone (GnRH) and combined gonadotropin therapy are effective to induce spermatogenesis in men with congenital hypogonadotropic hypogonadism (CHH). This study aimed to evaluate the effect of pulsatile GnRH therapy on spermatogenesis in male patients with CHH who had poor response to combined gonadotropin therapy.

Materials and methods

Patients who had poor response to combined gonadotropin therapy ≥ 6 months were recruited and shifted to pulsatile GnRH therapy. The rate of successful spermatogenesis, the median time to achieve spermatogenesis, serum gonadotropins, testosterone, and testicular volume were used for data analysis.

Results

A total of 28 CHH patients who had poor response to combined gonadotropin (HCG/HMG) therapy for 12.5 (6.0, 17.75) months were recruited and switched to pulsatile GnRH therapy for 10.0 (7.25, 16.0) months. Sperm was detected in 17/28 patients (60.7%). The mean time for the appearance of sperm in semen was 12.0 (7.5, 17.5) months. Compared to those who could not achieve spermatogenesis during pulsatile GnRH therapy, the successful group had a higher level of LH60min (4.32 vs. 1.10 IU/L, P = 0.043) and FSH60min (4.28 vs. 1.90 IU/L, P = 0.021). Testicular size increased during pulsatile GnRH therapy, compared to previous HCG/ HMG therapy (P < 0.05).

Conclusion

For CHH patients with prior poor response to one year of HCG/ HMG therapy, switching to pulsatile GnRH therapy may induce spermatogenesis.

Classes and predictors of reversal in male patients with congenital hypogonadotropic hypogonadism: a cross-sectional study of six international referral centres

BACKGROUND

Although some male patients with congenital hypogonadotropic hypogonadism (CHH) undergo spontaneous reversal following treatment, predictors of reversal remain elusive. We aimed to assemble the largest cohort of male patients with CHH reversal to date and identify distinct classes of reversal.

METHODS

This multicentre cross-sectional study was conducted in six international CHH referral centres in Brazil, Finland, France, Italy, the UK, and the USA. Adult men with CHH (ie, absent or incomplete spontaneous puberty by age 18 years, low serum testosterone concentrations, and no identifiable cause of hypothalamic-pituitary-gonadal [HPG] axis dysfunction) were eligible for inclusion. CHH reversal was defined as spontaneous recovery of HPG axis function off treatment. Centres provided common data elements on patient phenotype, clinical assessment, and genetics using a structured, harmonised data collection form developed by COST Action BM1105. Latent class mixture modelling (LCMM) was applied to establish whether at least two distinct classes of reversal could be identified and differentially predicted, and results were compared with a cohort of patients without CHH reversal to identify potential predictors of reversal. The primary outcome was the presence of at least two distinct classes of reversal.

FINDINGS

A total of 87 male patients with CHH reversal and 108 without CHH reversal were included in the analyses. LCMM identified two distinct reversal classes (75 [86%] in class 1 and 12 [14%] in class 2) on the basis of mean testicular volume, micropenis, and serum follicle-stimulating hormone (FSH) concentration. Classification probabilities were robust (0·998 for class 1 and 0·838 for class 2) and modelling uncertainty was low (entropy 0·90). Compared with class 1, patients in class 2 had significantly larger testicular volume (p<0·0001), no micropenis, and higher serum FSH concentrations (p=0·041), consistent with the Pasqualini syndrome (fertile eunuch) subtype of CHH. Patients without CHH reversal were more likely to have anosmia (p=0·016), cryptorchidism (p=0·0012), complete absence of puberty (testicular volume <4 cm³; p=0·0016), and two or more rare genetic variants (ie, oligogenicity; p=0·0001). Among patients who underwent genetic testing, no patients (of 75) with CHH reversal had a rare pathogenic ANOS1 variant compared with ten (11%) of 95 patients without CHH reversal. Individuals with CHH reversal had a significantly higher rate of rare variants in GNRHR than did those without reversal (nine [12%] of 75 vs three [3%] of 95; p=0·025).

INTERPRETATION

Applying LCMM to a large cohort of male patients with CHH reversal uncovered two distinct classes of reversal. Genetic investigation combined with careful clinical phenotyping could help surveillance of reversal after withdrawing treatment, representing the first tailored management approach for male patients with this rare endocrine disorder.

FUNDING

National Institutes of Health National Center for Advancing Translational Sciences; Ministry of Health, Rome, Italy; Ministry of University, Rome, Italy; National Institutes of Health Eunice Kennedy Shriver National Institute of Child Health and Human Development; and the Josiah Macy Jr Foundation.

TRANSLATION

For the Italian translation of the abstract see Supplementary Materials section.

Fertility outcomes in male adults with congenital hypogonadotropic hypogonadism treated during puberty with human chorionic gonadotropin and recombinant follicle stimulating hormone

AIM

Hormone replacement therapy with testosterone for pubertal induction in boys with congenital hypogonadotropic hypogonadism (CHH) achieves virilization but not spermatogenesis. By contrast, human chorionic gonadotropin (hCG) and recombinant follicle stimulating hormone (rFSH) provides both virilization and spermatogenesis. Fertility outcomes of boys treated with recombinant therapy during adolescence have been infrequently described. We report fertility induction and pregnancy outcomes in CHH patients treated with recombinant gonadotropins during puberty.

METHODS

Data of six subjects with CHH (n = 3 Kallmann syndrome & n = 3 Isolated hypogonadotropic hypogonadism) treated with hCG and FSH for pubertal induction were reviewed. Of these, five underwent subsequent fertility induction while one desired fertility at the end of pubertal induction.

RESULTS

Partners of all subjects achieved pregnancies using hCG and rFSH, all with full term live births. All infants were clinically normal.

CONCLUSION

This study provides early evidence of proof of concept of use of gonadotropin induction of puberty being beneficial in subsequent fertility outcome.

Frequency, morbidity and equity - the case for increased research on male fertility

Currently, most men with infertility cannot be given an aetiology, which reflects a lack of knowledge around gamete production and how it is affected by genetics and the environment. A failure to recognize the burden of male infertility and its potential as a biomarker for systemic illness exists. The absence of such knowledge results in patients generally being treated as a uniform group, for whom the strategy is to bypass the causality using medically assisted reproduction (MAR) techniques. In doing so, opportunities to prevent co-morbidity are missed and the burden of MAR is shifted to the woman. To advance understanding of men's reproductive health, longitudinal and multi-national centres for data and sample collection are essential. Such programmes must enable an integrated view of the consequences of genetics, epigenetics and environmental factors on fertility and offspring health. Definition and possible amelioration of the consequences of MAR for conceived children are needed. Inherent in this statement is the necessity to promote fertility restoration and/or use the least invasive MAR strategy available. To achieve this aim, protocols must be rigorously tested and the move towards personalized medicine encouraged. Equally, education of the public, governments and clinicians on the frequency and consequences of infertility is needed. Health options, including male contraceptives, must be expanded, and the opportunities encompassed in such investment understood. The pressing questions related to male reproductive health, spanning the spectrum of andrology are identified in the Expert Recommendation.

Improved phenotypic classification of male infertility to promote discovery of genetic causes

An increasing number of genes are being described in the context of non-syndromic male infertility. Linking the underlying genetic causes of non-syndromic male infertility with clinical data from patients is important to establish new genotype-phenotype correlations. This process can be facilitated by using universal nomenclature, but no standardized vocabulary is available in the field of non-syndromic male infertility. The International Male Infertility Genomics Consortium aimed at filling this gap, providing a standardized vocabulary containing nomenclature based on the Human Phenotype Ontology (HPO). The "HPO tree" was substantially revised compared with the previous version and is based on the clinical work-up of infertile men, including physical examination and hormonal assessment. Some causes of male infertility can already be suspected based on the patient's clinical history, whereas in other instances, a testicular biopsy is needed for diagnosis. We assembled 49 HPO terms that are linked in a logical hierarchy and showed examples of morphological features of spermatozoa and testicular histology of infertile men with identified genetic diagnoses to describe the phenotypes. This work will help to record patients' phenotypes systematically and facilitate communication between geneticists and andrologists. Collaboration across institutions will improve the identification of patients with the same phenotypes, which will promote the discovery of novel genetic causes for non-syndromic male infertility.

Outcomes and experiences of adults with congenital hypogonadism can inform improvements in the management of delayed puberty

Patients with congenital hypogonadism will encounter many health care professionals during their lives managing their health needs; from antenatal and infantile periods, through childhood and adolescence, into adult life and then old age. The pubertal transition from childhood to adult life raises particular challenges for diagnosis, therapy and psychological support, and patients encounter many pitfalls. Many patients with congenital hypogonadism and delayed or absent puberty are only diagnosed and treated after long diagnostic journeys, and their management across different centres and countries is not well standardised. Here we reconsider the management of pubertal delay, whilst addressing problematic diagnostic issues and highlighting the limitations of historic pubertal induction protocols - from the perspective of both an adult and a paediatric endocrinologist, dealing in our everyday work with the long-term adverse consequences to our hypogonadal patients of an incorrect and/or late diagnosis and treatment in childhood.

Additional mutation in PROKR2 and phenotypic differences in a Kallmann syndrome/normosmic congenital hypogonadotropic hypogonadism family carrying FGFR1 missense mutation

Congenital hypogonadotropic hypogonadism (CHH) is a genetically and clinically diverse disorder encompassing Kallmann syndrome (KS) and normosmic CHH (nCHH). Although mutations in numerous genes account for nearly 50% of CHH cases, a significant portion remains genetically uncharacterized. While most mutations follow the traditional Mendelian inheritance patterns, evidence suggests oligogenic interactions between CHH genes, acting as modifier genes to explain variable expressivity and incomplete penetrance associated with certain mutations.In this study, the proband presented with nCHH, while his son exhibited KS. We employed whole-exome sequencing (WES) to investigate the genetic differences between the two, and Sanger sequencing was used to validate the results obtained from WES.Genetic analysis revealed that both the proband and his son harboured a mutation in FGFR1 gene. Notably, an additional rare mutation in PROKR2 gene was exclusively identified in the son, which suggests the cause of the phenotypic difference between KS and nCHH.

The Emerging Therapeutic Potential of Kisspeptin and Neurokinin B

Kisspeptin (KP) and neurokinin B (NKB) are neuropeptides that govern the reproductive endocrine axis through regulating hypothalamic gonadotropin-releasing hormone (GnRH) neuronal activity and pulsatile GnRH secretion. Their critical role in reproductive health was first identified after inactivating variants in genes encoding for KP or NKB signaling were shown to result in congenital hypogonadotropic hypogonadism and a failure of pubertal development. Over the past 2 decades since their discovery, a wealth of evidence from both basic and translational research has laid the foundation for potential therapeutic applications. Beyond KP's function in the hypothalamus, it is also expressed in the placenta, liver, pancreas, adipose tissue, bone, and limbic regions, giving rise to several avenues of research for use in the diagnosis and treatment of pregnancy, metabolic, liver, bone, and behavioral disorders. The role played by NKB in stimulating the hypothalamic thermoregulatory center to mediate menopausal hot flashes has led to the development of medications that antagonize its action as a novel nonsteroidal therapeutic agent for this indication. Furthermore, the ability of NKB antagonism to partially suppress (but not abolish) the reproductive endocrine axis has supported its potential use for the treatment of various reproductive disorders including polycystic ovary syndrome, uterine fibroids, and endometriosis. This review will provide a comprehensive up-to-date overview of the preclinical and clinical data that have paved the way for the development of diagnostic and therapeutic applications of KP and NKB.

Identification and Analysis of Genes Related to Testicular Size in 14-Day-Old Piglets

The RNA-Seq technology was used to screen the key genes that affect the early development of the testes of Duroc × Landrace × Yorkshire piglets, to determine the regulatory pathway and provide reference for subsequent reproductive performance research, breeding, and other production practices. This study selected 14-day-old Duroc × Landrace × Yorkshire piglets as the trial animals. Testes from piglets with similar weights and no pathological changes were divided into small testis (ST) and large testis (LT) groups, and the RNA-Seq screening of differentially expressed genes (DEGs) was performed to find candidate genes and regulatory pathways related to early testicular development. The results show that 570 DEGs were found in the ST and LT groups, with 281 upregulated and 289 downregulated. The DEGs were mainly enriched on 47 gene ontology (GO) functional items. The Kyoto encyclopedia of genes and genotypes (KEGG) enrichment analysis found that there were 44 significantly enriched KEGG signal pathways, and the regulation of testicular development mainly focused on the arachidonic acid metabolism, Wnt signaling pathway and GnRH secretion pathways. The PTGES, SFRP1, SPP1, PLA2G4E, KCNJ5, PTGS2, and HCN1 genes were found to be as closely related to the testicular development of these Duroc × Landrace × Yorkshire piglets, and the differential gene expression was consistent with the real-time quantitative reverse transcription PCR (real-time qRT-PCR) validation results. This study was validated by high-throughput sequencing analysis and real-time qRT-PCR, and showed that the PTGES, SFRP1, SPP1, PLA2G4E, KCNJ5, PTGS2, and HCN1 genes may be involved in the regulation of germ cell development, spermatogenesis and semen traits. These should be further studied as candidate genes for early testicular development and reproductive trait regulation in boars.

Clinical challenge: When is delayed puberty more than a "late bloomer"?

Delayed puberty is a common reason for adolescents seeking consultation; most have constitutional delay of puberty (CDP) and will initiate puberty spontaneously although later than their peers. However, some individuals will not initiate or progress through puberty (i.e., congenital hypogonadotropic hypogonadism [CHH]). Differentiating CDP from CHH is diagnostically challenging. This article provides a high-level overview of this clinical challenge, underscores the importance of clinical ‘red flags’ facilitating diagnosis, and highlights a holistic, comprehensive approach to care.