Congenital idiopathic hypogonadotropic hypogonadism: evidence of defects in the hypothalamus, pituitary, and testes

Evaluating Sperm Recovery Time and Efficacy of Monotherapy vs. Combination Therapies in Men with Congenital Hypogonadotropic Hypogonadism: A Systematic Review and Meta-Analysis

PURPOSE

There is a lack of pooled data exploring the time and rates for human chorionic gonadotropin (hCG) monotherapy vs. combination therapies (hCG+human menopausal gonadotropin or recombinant human follicle-stimulating hormone) to restore spermatogenesis in azoospermic men with congenital hypogonadotropic hypogonadism (CHH). We aimed to investigate the time and rates to recover spermatogenesis among azoospermic CHH men receiving monotherapy vs. combination therapy.

MATERIALS AND METHODS

We conducted a systematic review and meta-analysis following the PRISMA guidelines. The search was performed on PubMed, EMBASE, Web of Science, and Scopus databases up to November 2023. Forrest plots were generated to visually present the pooled effect sizes for time to recover spermatogenesis, specifically employing the standardized mean difference (SMD). Publication bias was assessed utilizing funnel plots. PROSPERO ID: CRD42023473615.

RESULTS

The search identified 720 studies meeting inclusion criteria. Our meta-analysis of 1,240 men with CHH revealed significant differences in the time to recover spermatogenesis between combination therapies and monotherapy. The weighted mean recovery time was significantly shorter for combination therapies (10 months) compared to monotherapy (33 months). The SMD under the common effect model was 8.8 for combination therapies and 24.98 for monotherapy, indicating a more rapid recovery with combination therapies, p<0.01. The rates of sperm recovery were 66.76% for combination therapies and 51.9% for monotherapy, p=0.03. Significant heterogeneity was observed in both groups (I²=86% for combination therapies and I²=68% for monotherapy), suggesting considerable variation in individual responses.

CONCLUSIONS

The present meta-analysis reveals that in men with CHH, combination therapies expedite spermatogenesis recovery more than monotherapy. Additionally, combination therapies yield a higher rate of sperm appearing in the ejaculate as compared to hCG monotherapy. The significant heterogeneity observed in both groups underscores the variability in individual responses, warranting further investigation and caution in interpreting these results.

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.

Lack of a genetic risk continuum between pubertal timing in the general population and idiopathic hypogonadotropic hypogonadism

Pubertal timing is a highly heritable trait in the general population. Recently, a large-scale exome-wide association study has implicated rare variants in six genes (KDM4C, MC3R, MKRN3, PDE10A, TACR3, and ZNF483) as genetic determinants of pubertal timing within the general population. Two of the genes (TACR3, MKRN3) are already implicated in extreme disorders of pubertal timing. This observation suggests that there may be a pervasive "genetic risk continuum" wherein genes that govern pubertal timing in the general population, by extension, may also be causal for rare Mendelian disorders of pubertal timing. Hence, we hypothesized that the four novel genes linked to pubertal timing in the population will also contribute to idiopathic hypogonadotropic hypogonadism (IHH), a genetic disorder characterized by absent puberty. Exome sequencing data from 1322 unrelated IHH probands were reviewed for rare sequence variants (RSVs) (minor allele frequency bins: <1%; <0.1%; <0.01%) in the six genes linked to puberty in the general population. A gene-based rare variant association testing (RVAT) was performed between the IHH cohort and a reference public genomic sequences repository-the Genome Aggregation Database (gnomAD). As expected, RVAT analysis showed that RSVs in TACR3, a known IHH gene, were significantly enriched in the IHH cohort compared to gnomAD cohort across all three MAF bins. However, RVAT analysis of the remaining five genes failed to show any RSV enrichment in the IHH cohort across all MAF bins. Our findings argue strongly against a pervasive genetic risk continuum between pubertal timing in the general population and extreme pubertal phenotypes. The biologic basis of such distinct genetic architectures' merits further evaluation.

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.

Congenital hypogonadotropic hypogonadism in a patient with a de novo POGZ mutation

OBJECTIVE

Congenital hypogonadotropic hypogonadism (CHH) is a rare, genetically heterogeneous reproductive disorder caused by gonadotropin-releasing hormone (GnRH) deficiency. Approximately half of CHH patients also have decreased or absent sense of smell, that is, Kallmann syndrome (KS). We describe a patient with White-Sutton syndrome (developmental delay and autism spectrum disorder) and KS due to a heterozygous de novo mutation in POGZ (c.2857C>T, p.(Gln953*)), a gene encoding pogo transposable element derived with zinc finger domain, which acts as a transcriptomic regulator of neuronal networks.

DESIGN AND METHODS

We modeled the role of POGZ in CHH by generating 2 clonal human pluripotent stem cell lines with CRISPR/Cas9, carrying either the heterozygous patient mutation (H11 line) or a homozygous mutation (c.2803-2906del; p.E935Kfs*7 encoding a truncated POGZ protein; F6del line).

RESULTS

During the differentiation to GnRH neurons, neural progenitors derived from F6del line displayed severe proliferation defect, delayed wound-healing capacity, downregulation of intermediate progenitor neuron genes TBR1 and TBR2, and immature neuron markers PAX6 and TUBB3 and gave rise to fewer neurons with shorter neurites and less neurite branch points compared to the WT and H11 lines (P < .005). Both lines, however, could be successfully differentiated to GnRH neurons.

CONCLUSIONS

In conclusion, this is the first report on the overlap between White-Sutton syndrome and CHH. POGZ mutations do not hinder GnRH neuron formation but may cause CHH/KS by affecting the size and motility of the anterior neural progenitor pool and neurite outgrowth.

Clinical Characteristics and Genetic Analyses of Patients with Idiopathic Hypogonadotropic Hypogonadism

Objective

Idiopathic hypogonadotropic hypogonadism (IHH) is classified into two groups-Kalman syndrome and normosmic IHH (nIHH). Half of all cases can be explained by mutations in >50 genes. Targeted gene panel testing with nexrt generation sequencing (NGS) is required for patients without typical phenotypic findings. The aim was to determine the genetic etiologies of patients with IHH using NGS, including 54 IHH-associated genes, and to present protein homology modeling and protein stability analyzes of the detected variations.

Methods

Clinical and demographic data of 16 patients (eight female), aged between 11.6-17.8 years, from different families were assessed. All patients were followed up for a diagnosis of nIHH, had normal cranial imaging, were without anterior pituitary hormone deficiency other than gonadotropins, had no sex chromosome anomaly, had no additional disease, and underwent genetic analysis with NGS between the years 2008-2021. Rare variants were classified according to the variant interpretation framework of the American College of Medical Genetics and Genomics (ACMG)/Association for Molecular Pathology. Changes in protein structure caused by variations were modeled using RoseTTAFold and changes in protein stability resulting from variation were analyzed.

Results

Half of the 16 had no detectable variation. Three (18.75%) had a homozygous (pathogenic) variant in the GNRHR gene, one (6.25%) had a compound heterozygous [likely pathogenic-variants of uncertain significance (VUS)] variant in PROK2 and four (25%) each had a heterozygous (VUS) variant in HESX1, FGF8, FLRT3 and DMXL2. Protein models showed that variants interpreted as VUS according to ACMG could account for the clinical IHH.

Conclusion

The frequency of variation detection was similar to the literature. Modelling showed that the variant in five different genes, interpreted as VUS according to ACMG, could explain the clinical IHH.

Reproductive Phenotypes and Genotypes in Men With IHH

CONTEXT

Isolated hypogonadotropic hypogonadism (IHH) is phenotypically and genetically heterogeneous.

OBJECTIVE

This work aimed to determine the correlation between genotypic severity with pubertal and neuroendocrine phenotypes in IHH men.

METHODS

A retrospective study was conducted (1980-2020) examining olfaction (Kallmann syndrome [KS] vs normosmic IHH [nHH]), baseline testicular volume (absent vs partial puberty), neuroendocrine profiling (pulsatile vs apulsatile luteinizing hormone [LH] secretion), and genetic variants in 62 IHH-associated genes through exome sequencing (ES).

RESULTS

In total, 242 men (KS: n = 131 [54%], nHH: n = 111 [46%]) were included. Men with absent puberty had significantly lower gonadotropin levels (P < .001) and were more likely to have undetectable LH (P < .001). Logistic regression showed partial puberty as a statistically significant predictor of pulsatile LH secretion (R2 = 0.71, P < .001, OR: 10.8; 95% CI, 3.6-38.6). Serum LH of 2.10 IU/L had a 95% true positive rate for predicting LH pulsatility. Genetic analyses in 204 of 242 IHH men with ES data available revealed 36 of 204 (18%) men carried protein-truncating variants (PTVs) in 12 IHH genes. Men with absent puberty and apulsatile LH were enriched for oligogenic PTVs (P < .001), with variants in ANOS1 being the predominant PTV in this genotype-phenotype association. Men with absent puberty were enriched for ANOS1 PTVs compared to partial puberty counterparts (P = .002). PTVs in other IHH genes imparted more variable reproductive phenotypic severity.

CONCLUSION

Partial puberty and LH greater than or equal to 2.10 IU/L are proxies for pulsatile LH secretion. ANOS1 PTVs confer severe reproductive phenotypes. Variable phenotypic severity in the face of severe genetic variants in other IHH genes point to significant neuroendocrine plasticity of the HPG axis in IHH men.

[Puberty induction in boys with congenital isolated hypogonadotropic hypogonadism]

BACKGROUND

Gonadotropin therapy in boys with congenital isolated hypogonadotropic hypogonadism helps to increase testes volume and induce spermatogenesis in comparison with testosterone therapy. However, difficulties with dose titration, partial therapy success, absence of generally accepted regimen protocols don't allow to use this therapy in order to induce puberty in adolescents with Kallmann syndrome or normosmic hypogonadotropic hypogonadism.

AIM

To assess the effectiveness of combination hormonal replacement therapy via human chorionic gonadotropin and recombinant follicle stimulation hormone in adolescents with congenital isolated normosmic hypogonadotropic hypogonadism and with Kallmann syndromeMATERIALS AND METHODS: This is an open single-center prospective non-controlled study. Boys with hypogonadotropic hypogonadism were receiving hormonal replacement therapy for 12 months. Initial dose of human chorionic gonadotropin was 500 IU per week. Initial dose of recombinant follicle stimulation hormone was 37.5 IU per week. Doses were doubled in 6 months. Antropometric data, Tanner stage, testes volumes, inhibin B and anti-Mullerian hormone (AMH) levels were evaluated in all the patients before the treatment, after 6 and 12 months of the therapy.

RESULTS

8 boys with hypogonadotropic hypogonadism were included into the study. Median age before therapy initiation was 15.7 years [15.33; 16.41]. In 12 months after the therapy initiation puberty development, testosterone increase from 0.44 [0.34;0.62] to 4.39 [0.88;10.51] nmol/l (p=0.012), AMH decrease from 35.70 [18.00;59.00] to 14.41 [11.60;16.65] ng/ml were noted in all the patients (p=0.017). Testes volumes increase and inhibin B level increase were not statistically significant.

CONCLUSION

Gonadotropin therapy is effective in order to puberty initiation in adolescents with congenital hypogonadotropic hypogonadism. In helps to achieve not only androgenization, but also to Sertoli cells maturation.

The use of hormone stimulation in male infertility

Infertility affects 15% of couples worldwide and in approximately 50% of cases the cause is secondary to an abnormality of the sperm. However, treatment options for male infertility are limited and empirical use of hormone stimulation has been utilised. We review the contemporary data regarding the application of hormone stimulation to treat male infertility. There is strong evidence supporting the use of hormone stimulation in hypogonadotropic hypogonadism but there is inadequate evidence for all other indications.

Reversible hypogonadotropic hypogonadism in men with the fertile eunuch/Pasqualini syndrome: A single-center natural history study

Congenital hypogonadotropic hypogonadism (HH) is a heterogeneous genetic disorder characterized by disrupted puberty and infertility. In most cases, HH is abiding yet 10-15% undergo reversal. Men with HH and absent and partial puberty (i.e., testicular volume <4mL and >4mL respectively) have been well-studied, but the rare fertile eunuch (FE) variant remains poorly characterized. This natural history study of 240 men with HH delineates the clinical presentation, neuroendocrine profile, rate of reversal and genetics of the FE variant. We compared three HH groups: FE (n=38), absent puberty (n=139), and partial puberty (n=63). The FE group had no history of micropenis and 2/38 (5%) had cryptorchidism (p<0.0001 vs. other groups). The FE group exhibited higher rates of detectable gonadotropins, higher mean LH/FSH levels, and higher serum inhibin B levels (all p<0.0001). Neuroendocrine profiling showed pulsatile LH secretion in 30/38 (79%) of FE men (p<0.0001) and 16/36 (44%) FE men underwent spontaneous reversal of HH (p<0.001). The FE group was enriched for protein-truncating variants (PTVs) in GNRHR and FGFR1 and 4/30 (13%) exhibited oligogenic PTVs. Findings suggest men with the FE variant exhibit the mildest neuroendocrine defects of HH men and the FE sub-type represents the first identified phenotypic predictor for reversible HH.

Follicle-stimulating hormone signaling in Sertoli cells: a licence to the early stages of spermatogenesis

Follicle-stimulating hormone signaling is essential for the initiation and early stages of spermatogenesis. Follicle-stimulating hormone receptor is exclusively expressed in Sertoli cells. As the only type of somatic cell in the seminiferous tubule, Sertoli cells regulate spermatogenesis not only by controlling their own number and function but also through paracrine actions to nourish germ cells surrounded by Sertoli cells. After follicle-stimulating hormone binds to its receptor and activates the follicle-stimulating hormone signaling pathway, follicle-stimulating hormone signaling will establish a normal Sertoli cell number and promote their differentiation. Spermatogonia pool maintenance, spermatogonia differentiation and their entry into meiosis are also positively regulated by follicle-stimulating hormone signaling. In addition, follicle-stimulating hormone signaling regulates germ cell survival and limits their apoptosis. Our review summarizes the aforementioned functions of follicle-stimulating hormone signaling in Sertoli cells. We also describe the clinical potential of follicle-stimulating hormone treatment in male patients with infertility. Furthermore, our review may be helpful for developing better therapies for treating patients with dysfunctional follicle-stimulating hormone signaling in Sertoli cells.

International consensus statement on allergy and rhinology: Olfaction

BACKGROUND

The literature regarding clinical olfaction, olfactory loss, and olfactory dysfunction has expanded rapidly over the past two decades, with an exponential rise in the past year. There is substantial variability in the quality of this literature and a need to consolidate and critically review the evidence. It is with that aim that we have gathered experts from around the world to produce this International Consensus on Allergy and Rhinology: Olfaction (ICAR:O).

METHODS

Using previously described methodology, specific topics were developed relating to olfaction. Each topic was assigned a literature review, evidence-based review, or evidence-based review with recommendations format as dictated by available evidence and scope within the ICAR:O document. Following iterative reviews of each topic, the ICAR:O document was integrated and reviewed by all authors for final consensus.

RESULTS

The ICAR:O document reviews nearly 100 separate topics within the realm of olfaction, including diagnosis, epidemiology, disease burden, diagnosis, testing, etiology, treatment, and associated pathologies.

CONCLUSION

This critical review of the existing clinical olfaction literature provides much needed insight and clarity into the evaluation, diagnosis, and treatment of patients with olfactory dysfunction, while also clearly delineating gaps in our knowledge and evidence base that we should investigate further.

Cross-sectional, Neuromuscular Phenotyping Study of Arhinia Patients With SMCHD1 Variants

BACKGROUND AND OBJECTIVES

Facioscapulohumeral muscular dystrophy type 2 (FSHD2) and arhinia are two distinct disorders caused by pathogenic variants in the same gene, SMCHD1. The mechanism underlying this phenotypic divergence remains unclear. In this study, we characterize the neuromuscular phenotype of individuals with arhinia caused by SMCHD1 variants and analyze their complex genetic and epigenetic criteria to assess their risk for FSHD2.

METHODS

Eleven individuals with congenital nasal anomalies, including arhinia, nasal hypoplasia, or anosmia, underwent a neuromuscular exam, genetic testing, muscle ultrasound, and muscle MRI. Risk for FSHD2 was determined by combined genetic and epigenetic analysis of 4q35 haplotype, D4Z4 repeat length and methylation profile. We also compared expression levels of pathogenic DUX4 mRNA in primary myoblasts or dermal fibroblasts (upon myogenic differentiation or epigenetic transdifferentiation, respectively) in these individuals to those with confirmed FSHD2.

RESULTS

Among the eleven individuals with rare, pathogenic, heterozygous missense variants in exons 3-11 of SMCHD1, only a subset (n=3/11; 1 male, 2 females; age 25-51 years) met the strict genetic and epigenetic criteria for FSHD2 (D4Z4 repeat unit length <21 in cis with a 4qA haplotype, and D4Z4 methylation <30%). None of the 3 individuals had typical clinical manifestations or muscle imaging findings consistent with FSHD2. However, the arhinia patients meeting the permissive genetic and epigenetic criteria for FSHD2 displayed some DUX4 expression in dermal fibroblasts under the epigenetic de-repression by drug treatment and in the primary myoblasts undergoing myogenic differentiation.

DISCUSSION

In this cross-sectional study, we identified arhinia patients who meet the full genetic and epigenetic criteria for FSHD2 and display the molecular hallmark of FSHD, that is DUX4 de-repression and expression in vitro, but who do not manifest with the typical clinicopathologic phenotype of FSHD2. The distinct dichotomy between FSHD2 and arhinia phenotypes despite an otherwise poised DUX4 locus implies the presence of novel disease-modifying factors that seem to operate as a "switch", resulting in one phenotype and not the other. Identification and further understanding of these disease-modifying factors will likely provide valuable insight with therapeutic implications for both diseases.

Genetics of congenital olfactory dysfunction: a systematic review of the literature

Olfaction, as one of our 5 senses, plays an important role in our daily lives. It is connected to proper nutrition, social interaction, and protection mechanisms. Disorders affecting this sense consequently also affect the patients' general quality of life. Because the underlying genetics of congenital olfactory disorders (COD) have not been thoroughly investigated yet, this systematic review aimed at providing information on genes that have previously been reported to be mutated in patients suffering from COD. This was achieved by systematically reviewing existing literature on 3 databases, namely PubMed, Ovid Medline, and ISI Web of Science. Genes and the type of disorder, that is, isolated and/or syndromic COD were included in this study, as were the patients' associated abnormal features, which were categorized according to the affected organ(-system). Our research yielded 82 candidate genes/chromosome loci for isolated and/or syndromic COD. Our results revealed that the majority of these are implicated in syndromic COD, a few accounted for syndromic and isolated COD, and the least underly isolated COD. Most commonly, structures of the central nervous system displayed abnormalities. This study is meant to assist clinicians in determining the type of COD and detecting potentially abnormal features in patients with confirmed genetic variations. Future research will hopefully expand this list and thereby further improve our understanding of COD.

Correlation Analysis of Genotypes and Phenotypes in Chinese Male Pediatric Patients With Congenital Hypogonadotropic Hypogonadism

Congenital hypogonadotropic hypogonadism (CHH) can be divided into Kallmann syndrome (KS) and normosmic HH (nHH). The clinical and genetic characteristics of CHH have been studied in adults, but less in pre-adults. The medical records of patients with CHH in our gonad disease database from 2008 to 2020 were evaluated. In total, 125 patients aged 0 to 18 years were enrolled in our study. KS patients had a higher incidence of micropenis compared with nHH (86.2% vs. 65.8%, p=0.009), and 7 patients (5.6%) had hypospadias. Among the 39 patients with traceable family history, delayed puberty, KS/nHH, and olfactory abnormalities accounted for 56.4%, 17.9%, and 15.4%, respectively. In total, 65 patients completed the hCG prolongation test after undergoing the standard hCG test, and the testosterone levels of 24 patients (22.9%) were still lower than 100 ng/dL. In 77 patients, 25 CHH-related genes were identified, including digenic and trigenic mutations in 23 and 3 patients, respectively. The proportion of oligogenic mutations was significantly higher than that in our previous study (27.7% vs. 9.8%). The most common pathogenic genes were FGFR1, PROKR2, CHD7 and ANOS1. The incidence rate of the genes named above was 21.3%, 18.1%, 12.8% and 11.7%, respectively; all were higher than those in adults (<10%). Most mutations in CHH probands were private, except for W178S in PROKR2, V560I in ANOS1, H63D in HS6ST1, and P191L and S671L in IL17RD. By analyzing family history and genes, we found that both PROKR2 and KISS1R may also be shared between constitutional delay of growth and puberty (CDGP) and CHH. L173R of PROKR2 accounts for 40% of the CHH population in Europe and the United States; W178S of PROKR2 accounts for 58.8% of Chinese CHH patients. Micropenis and cryptorchidism are important cues for CHH in children. They are more common in pediatric patients than in adult patients. It is not rare of Leydig cell dysfunction (dual CHH), neither of oligogenic mutations diagnosed CHH in children. Both PROKR2 and KISS1R maybe the potential shared pathogenic genes of CDGP and CHH, and W178S in PROKR2 may be a founder mutation in Chinese CHH patients.

Targeting trafficking as a therapeutic avenue for misfolded GPCRs leading to endocrine diseases

G protein-coupled receptors (GPCRs) are plasma membrane proteins associated with an array of functions. Mutations in these receptors lead to a number of genetic diseases, including diseases involving the endocrine system. A particular subset of loss-of-function mutant GPCRs are misfolded receptors unable to traffic to their site of function (i.e. the cell surface plasma membrane). Endocrine disorders in humans caused by GPCR misfolding include, among others, hypo- and hyper-gonadotropic hypogonadism, morbid obesity, familial hypocalciuric hypercalcemia and neonatal severe hyperparathyroidism, X-linked nephrogenic diabetes insipidus, congenital hypothyroidism, and familial glucocorticoid resistance. Several in vitro and in vivo experimental approaches have been employed to restore function of some misfolded GPCRs linked to endocrine disfunction. The most promising approach is by employing pharmacological chaperones or pharmacoperones, which assist abnormally and incompletely folded proteins to refold correctly and adopt a more stable configuration to pass the scrutiny of the cell's quality control system, thereby correcting misrouting. This review covers the most important aspects that regulate folding and traffic of newly synthesized proteins, as well as the experimental approaches targeted to overcome protein misfolding, with special focus on GPCRs involved in endocrine diseases.

[Molecular genetics and phenotypic features of congenital isolated hypogonadotropic hypogonadism]

Congenital isolated hypogonadotropic hypogonadism includes a group of diseases related to the defects of secretion and action of gonadotropin-releasing hormone (GNRH) and gonadotropins. In a half of cases congenital hypogonadism is associated with an impaired sense of smell. It's named Kallmann syndrome. Now 40 genes are known to be associated with function of hypothalamus pituitary gland and gonads. Phenotypic features of hypogonadism and therapy effectiveness are related to different molecular defects. However clinical signs may vary even within the same family with the same molecular genetic defect. Genotype phenotype correlation in patients with congenital malformations prioritizes the search for mutations in candidate genes. There are data of significant contribution of oligogenicity into the phenotype of the disease are presented in the review. Moreover, an issue of current isolated hypogonadotropic hypogonadism definition and classification revision is raised in the review due to hypogonadotropic hypogonadism development while there are mutations in genes not associated with GNRH neurons secretion and function.

Conditional Fgfr1 Deletion in GnRH Neurons Leads to Minor Disruptions in the Reproductive Axis of Male and Female Mice

In humans and mice, inactivating mutations in fibroblast growth factor receptor 1 (Fgfr1) lead to gonadotropin-releasing hormone (GnRH) deficiency and a host of downstream reproductive disorders. It was unclear if Fgfr1 signaling directly upon GnRH neurons critically drove the establishment of a functional GnRH system. To answer this question, we generated a mouse model with a conditional deletion of Fgfr1 in GnRH neurons using the Cre/loxP approach. These mice, called Fgfr1cKO mice, were examined along with control mice for their pubertal onset and a host of reproductive axis functions. Our results showed that Fgfr1cKO mice harbored no detectable defects in the GnRH system and pubertal onset, suffered only subtle changes in the pituitary function, but exhibited significantly disrupted testicular and ovarian morphology at 25 days of age, indicating impaired gametogenesis at a young age. However, these disruptions were transient and became undetectable in older mice. Our results suggest that Fgfr1 signaling directly on GnRH neurons supports, to some extent, the reproductive axis function in the period leading to the early phase of puberty, but is not critically required for pubertal onset or reproductive maintenance in sexually mature animals.

GnRH stimulation testing and serum inhibin B in males: insufficient specificity for discriminating between congenital hypogonadotropic hypogonadism from constitutional delay of growth and puberty

STUDY QUESTION

Are GnRH tests and serum inhibin B levels sufficiently discriminating to distinguish transient constitutional delay of growth and puberty (CDGP) from congenital hypogonadotropic hypogonadism (CHH) that affects reproductive health for life?

SUMMARY ANSWER

Both parameters lack the specificity to discriminate CDGP from CHH.

WHAT IS KNOWN ALREADY

GnRH tests and inhibin B levels have been proposed to differentiate CDGP from CHH. However, their diagnostic accuracies have been hampered by the small numbers of CHH included and enrichment of CHH patients with more severe forms.

STUDY DESIGN, SIZE, DURATION

The aim of this study was to assess the diagnostic performance of GnRH tests and inhibin B measurements in a large cohort of CHH male patients with the whole reproductive spectrum. From 2008 to 2018, 232 males were assessed: 127 with CHH, 74 with CDGP and 31 healthy controls.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The participants were enrolled in two French academic referral centres. The following measurements were taken: testicular volume (TV), serum testosterone, inhibin B, LH and FSH, both at baseline and following the GnRH test.

MAIN RESULTS AND THE ROLE OF CHANCE

Among CHH patients, the LH response to the GnRH test was very variable and correlated with TV. Among CDGP patients, the LH peak was also variable and 47% of CHH patients had peak LH levels overlapping with the CDGP group. However, no patients with CDGP had an LH peak below 4.0 IU/l, while 53% CHH patients had LH peak below this threshold. Among CHH patients, inhibin B levels were also variable and correlated with TV and peak LH. Inhibin B was significantly lower in CHH patients than in CDGP patients but 50% of CHH values overlapped with CDGP values. Interestingly, all patients with CDGP had inhibin B levels above 35 pg/ml but 50% of CHH patients also had levels above this threshold.

LIMITATIONS, REASONS FOR CAUTION

As CHH is very rare, an international study would be necessary to recruit a larger CHH cohort and consolidate the conclusion reached here.

WIDER IMPLICATIONS OF THE FINDINGS

Peak LH and basal inhibin B levels are variable in both CHH and CDGP with significant overlap. Both parameters lack specificity and sensitivity to efficiently discriminate CHH from CDGP. This reflects the varying degree of gonadotropin deficiency inherent to CHH. These two diagnostic procedures may misdiagnose partial forms of isolated (non-syndromic) CHH, allowing them to be erroneously considered as CDGP.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by Agence Française de Lutte contre le Dopage: Grant Hypoproteo AFLD-10 (to J.Y.); Agence Nationale de la Recherche (ANR): Grant ANR-09-GENO-017-01 (to J.Y.); European Cooperation in Science and Technology, COST Action BM1105; Programme Hospitalier de Recherche Clinique (PHRC), French Ministry of Health: PHRC-2009 HYPO-PROTEO (to J.Y.); and Programme Hospitalier de Recherche Clinique (PHRC) “Variété”, French Ministry of Health, N° P081216/IDRCB 2009-A00892-55 (to P.C.). There are no competing interests.

TRIAL REGISTRATION NUMBER

N/A

Spermatogenesis of Male Patients with Congenital Hypogonadotropic Hypogonadism Receiving Pulsatile Gonadotropin-Releasing Hormone Therapy Versus Gonadotropin Therapy: A Systematic Review and Meta-Analysis

Purpose

Pulsatile gonadotropin-releasing hormone (GnRH) therapy and gonadotropin therapy (GT) were widely used for male patients with congenital hypogonadotropic hypogonadism (CHH), but their efficacy was not well compared before. We conducted this meta-analysis to compare the efficacy of restoring fertility using these two therapies.

Materials and Methods

PubMed, Web of Science, and Scopus were systematically searched for comparative studies evaluating the efficiency of GnRH therapy and GT for male patients with CHH. For continuous outcomes, the weighted mean difference (WMD) was used to measure the difference, whereas the risk ratio with 95% confidence interval was calculated for binary variables.

Results

Overall, eight articles from seven studies with 420 patients enrolled were included in the analysis. Patients from the two different groups were determined to be comparable in age, proportion with Kallmann syndrome, percentage of cryptorchidism and pretreatment hormones (follicular-stimulating hormone, luteinizing hormone, and testosterone). GnRH therapy was related to a larger testicular volume (standardized mean difference=−1.43; p=0.01) and earlier spermatogenesis (WMD=−5.30 months; p=0.004) compared to GT. However, the difference in the rate of positive sperm detection (p=0.08), sperm concentration (p=0.37), and pregnancy rate (p=0.11) were not significant. Allergic reactions mostly occurred during GnRH therapy, while GT was related to a higher incidence of gynecomastia and acne.

Conclusions

Compared to GT, GnRH was related to earlier spermatogenesis and less estradiol-related adverse reactions, although there were no significant differences in spermatogenesis rate, sperm concentration, and pregnancy rate. High-quality randomized controlled trials are needed for future research.

Prospects for FSH Treatment of Male Infertility

CONTEXT

Despite the new opportunities provided by assisted reproductive technology (ART), male infertility treatment is far from being optimized. One possibility, based on pathophysiological evidence, is to stimulate spermatogenesis with gonadotropins.

EVIDENCE ACQUISITION

We conducted a comprehensive systematic PubMed literature review, up to January 2020, of studies evaluating the genetic basis of follicle-stimulating hormone (FSH) action, the role of FSH in spermatogenesis, and the effects of its administration in male infertility. Manuscripts evaluating the role of genetic polymorphisms and FSH administration in women undergoing ART were considered whenever relevant.

EVIDENCE SYNTHESIS

FSH treatment has been successfully used in hypogonadotropic hypogonadism, but with questionable results in idiopathic male infertility. A limitation of this approach is that treatment plans for male infertility have been borrowed from hypogonadism, without daring to overstimulate, as is done in women undergoing ART. FSH effectiveness depends not only on its serum levels, but also on individual genetic variants able to determine hormonal levels, activity, and receptor response. Single-nucleotide polymorphisms in the follicle-stimulating hormone subunit beta (FSHB) and follicle-stimulating hormone receptor (FSHR) genes have been described, with some of them affecting testicular volume and sperm output. The FSHR p.N680S and the FSHB -211G>T variants could be genetic markers to predict FSH response.

CONCLUSIONS

FSH may be helpful to increase sperm production in infertile men, even if the evidence to recommend the use of FSH in this setting is weak. Placebo-controlled clinical trials, considering the FSHB-FSHR haplotype, are needed to define the most effective dosage, the best treatment length, and the criteria to select candidate responder patients.

Insight Into the Ontogeny of GnRH Neurons From Patients Born Without a Nose

CONTEXT

The reproductive axis is controlled by a network of gonadotropin-releasing hormone (GnRH) neurons born in the primitive nose that migrate to the hypothalamus alongside axons of the olfactory system. The observation that congenital anosmia (inability to smell) is often associated with GnRH deficiency in humans led to the prevailing view that GnRH neurons depend on olfactory structures to reach the brain, but this hypothesis has not been confirmed.

OBJECTIVE

The objective of this work is to determine the potential for normal reproductive function in the setting of completely absent internal and external olfactory structures.

METHODS

We conducted comprehensive phenotyping studies in 11 patients with congenital arhinia. These studies were augmented by review of medical records and study questionnaires in another 40 international patients.

RESULTS

All male patients demonstrated clinical and/or biochemical signs of GnRH deficiency, and the 5 men studied in person had no luteinizing hormone (LH) pulses, suggesting absent GnRH activity. The 6 women studied in person also had apulsatile LH profiles, yet 3 had spontaneous breast development and 2 women (studied from afar) had normal breast development and menstrual cycles, suggesting a fully intact reproductive axis. Administration of pulsatile GnRH to 2 GnRH-deficient patients revealed normal pituitary responsiveness but gonadal failure in the male patient.

CONCLUSIONS

Patients with arhinia teach us that the GnRH neuron, a key gatekeeper of the reproductive axis, is associated with but may not depend on olfactory structures for normal migration and function, and more broadly, illustrate the power of extreme human phenotypes in answering fundamental questions about human embryology.

Follicle-stimulating Hormone (FSH) Action on Spermatogenesis: A Focus on Physiological and Therapeutic Roles

BACKGROUND

Human reproduction is regulated by the combined action of the follicle-stimulating hormone (FSH) and the luteinizing hormone (LH) on the gonads. Although FSH is largely used in female reproduction, in particular in women attending assisted reproductive techniques to stimulate multi-follicular growth, its efficacy in men with idiopathic infertility is not clearly demonstrated. Indeed, whether FSH administration improves fertility in patients with hypogonadotropic hypogonadism, the therapeutic benefit in men presenting alterations in sperm production despite normal FSH serum levels is still unclear. In the present review, we evaluate the potential pharmacological benefits of FSH administration in clinical practice.

METHODS

This is a narrative review, describing the FSH physiological role in spermatogenesis and its potential therapeutic action in men.

RESULTS

The FSH role on male fertility is reviewed starting from the physiological control of spermatogenesis, throughout its mechanism of action in Sertoli cells, the genetic regulation of its action on spermatogenesis, until the therapeutic options available to improve sperm production.

CONCLUSION

FSH administration in infertile men has potential benefits, although its action should be considered by evaluating its synergic action with testosterone, and well-controlled, powerful trials are required. Prospective studies and new compounds could be developed in the near future.

FSH for the Treatment of Male Infertility

Follicle-stimulating hormone (FSH) supports spermatogenesis acting via its receptor (FSHR), which activates trophic effects in gonadal Sertoli cells. These pathways are targeted by hormonal drugs used for clinical treatment of infertile men, mainly belonging to sub-groups defined as hypogonadotropic hypogonadism or idiopathic infertility. While, in the first case, fertility may be efficiently restored by specific treatments, such as pulsatile gonadotropin releasing hormone (GnRH) or choriogonadotropin (hCG) alone or in combination with FSH, less is known about the efficacy of FSH in supporting the treatment of male idiopathic infertility. This review focuses on the role of FSH in the clinical approach to male reproduction, addressing the state-of-the-art from the little data available and discussing the pharmacological evidence. New compounds, such as allosteric ligands, dually active, chimeric gonadotropins and immunoglobulins, may represent interesting avenues for future personalized, pharmacological approaches to male infertility.

Correlations Among Genotype and Outcome in Chinese Male Patients With Congenital Hypogonadotropic Hypogonadism Under HCG Treatment

BACKGROUND

Congenital hypogonadotropic hypogonadism (CHH) is a genetically heterogeneous disorder characterized by absent or incomplete puberty and infertility, and heterogeneous responses are often observed during treatment.

AIM

To investigate the role of CHH-associated variants in patients with CHH with poor responses to human chorionic gonadotropin (hCG).

METHODS

This retrospective study investigated 110 Chinese male patients with CHH undergoing genetic analysis and hCG treatment. CHH-associated rare sequence variants (RSVs) were identified by using a tailored next-generation sequencing panel and were interpreted in accordance with the American College of Medical Genetics and Genomics criteria. Clinical characteristics were recorded, and Kyoto Encyclopedia of Genes and Genomes analysis was conducted to assess pathways enriched in protein networks implicated in poor responses.

OUTCOMES

The outcomes include testicular volume, serum hormonal profiles, parameters of semen analysis, pathogenicity classification, and pathway enrichment.

RESULTS

Among the 110 patients, 94.55% achieved normal serum testosterone and 54.55% achieved seminal spermatozoa appearance (SSA). PLXNB1, ROBO3, LHB, NRP2, CHD7, and PLXNA1 RSVs were identified in patients who had an abnormal serum testosterone level during treatment. In spermatogenesis, the number of CHH-associated RSVs was not significantly strongly associated with delayed SSA. After pathogenicity classification, pathogenic/likely pathogenic (P/LP) RSVs were identified in 30% (33/110) of patients. Patients with P/LP RSVs showed delayed SSA compared with noncarriers, and P/LP PROKR2 RSVs showed the strongest association (48, 95% CI: 34.1-61.9 months, P = .043). Enriched pathways implicated in delayed SSA included neuroactive ligand-receptor interaction; Rap1, MAPK, PI3K-Akt signaling; and regulation of actin cytoskeleton.

CLINICAL IMPLICATIONS

Male patients with CHH harboring P/LP PROKR2 RSVs should be aware of a high probability of poor responses to hCG; If these patients desire fertility, it might be better to recommend hCG/human menopausal gonadotropin, hCG/recombinant follicle-stimulating hormone, or pulsatile GnRH administration before treatments start or as early as possible.

STRENGTHS & LIMITATIONS

Strengths are the standardized regimen and extensive follow-up (median time of 40 months). However, included patients in the study voluntarily chose hCG treatment because of the burden of drug cost and/or little fertility desire. Therefore, human menopausal gonadotropin or follicle-stimulating hormone was not added to this cohort. Our observed correlations should be further verified in patients with CHH undergoing other treatments.

CONCLUSION

Among all P/LP RSVs, P/LP PROKR2 RSVs might correlate with poor responses in CHH under hCG treatment; our study supports the pathogenicity assessment of American College of Medical Genetics and Genomics criteria in genetic counseling, to improve management of patients with CHH. Chen Y, Sun T, Niu Y, et al. Correlations AmongGenotype and Outcome in Chinese Male Patients WithCongenital Hypogonadotropic Hypogonadism Under HCG Treatment. J Sex Med 2020;17:645-657.

Spontaneous fertility and variable spectrum of reproductive phenotype in a family with adult-onset X-linked adrenal insufficiency harboring a novel DAX-1/NR0B1 mutation

BACKGROUND

Adrenal hypoplasia congenita (AHC) is an X-linked disorder that affects the adrenal cortex and hypothalamus-pituitary-gonadal axis (HPG), leading to primary adrenocortical insufficiency (PAI) and hypogonadotropic hypogonadism. AHC is caused by a mutation in the DAX-1 gene (NR0B1). More commonly, this disease is characterized by early-onset PAI, with symptoms in the first months of life. However, a less severe phenotype termed late-onset AHC has been described, as PAI signs and symptoms may begin in adolescence and adulthood. Here we describe a family report of a novel mutation within NR0B1 gene and variable reproductive phenotypes, including spontaneous fertility, in a very late-onset X-linked AHC kindred.

CASE PRESENTATION

Three affected maternal male relatives had confirmed PAI diagnosis between 30 y and at late 64 y. The X-linked pattern has made the endocrinology team to AHC suspicion. Regarding the HPG axis, all males presented a distinct degree of testosterone deficiency and fertility phenotypes, varying from a variable degree of hypogonadism, oligoasthenoteratozoospermia to spontaneous fertility. Interestingly, the other five maternal male relatives unexpectedly died during early adulthood, most likely due to undiagnosed PAI/adrenal crisis as the probable cause of their premature deaths. Sequencing analysis of the NR0B1 gene has shown a novel NR0B1 mutation (p.Tyr378Cys) that segregated in three AHC family members.

CONCLUSIONS

NR0B1 p.Tyr378Cys segregates in an AHC family with a variable degree of adrenal and gonadal phenotypes, and its hemizygous trait explains the disease in affected family members. We recommend that NR0B1 mutation carriers, even those that are allegedly asymptomatic, be carefully monitored while reinforcing education to prevent PAI and consider early sperm banking when spermatogenesis still viable.

Clinical Characteristics and Spermatogenesis in Patients with Congenital Hypogonadotropic Hypogonadism Caused by FGFR1 Mutations

OBJECTIVE

The aim of this study was to investigate the clinical characteristics of patients diagnosed with congenital hypogonadotropic hypogonadism (CHH) caused by FGFR1 (fibroblast growth factor receptor 1) gene mutations and to evaluate the effect of gonadotropin or pulsatile gonadotropin-releasing hormone (GnRH) therapy on spermatogenesis.

METHODS

A retrospective study was conducted on CHH patients admitted to Peking Union Medical College Hospital from January 2012 to March 2020. Clinical features and laboratory results were recorded. Testicular volume and sperm count responding to gonadotropin and pulsatile GnRH therapy were compared between the FGFR1 mutation group and the mutation-negative group.

RESULTS

(1) FGFR1 mutation group included 14 patients who received sperm-induction therapy, and the mutation-negative group enrolled 25 CHH patients. (2) The incidence of cryptorchidism was 50.0% (7/14) and 12.0% (3/25) in the FGFR1 group and the mutation-negative group, respectively (p=0.019). The baseline testicular volume of the FGFR1 mutation group was smaller than that of the mutation-negative group, 1.6 (0.5-2.0) mL vs. 2 (1.75-4) mL (p=0.033). The baseline luteinizing hormone (LH), Follicle-stimulating hormone (FSH), and testosterone levels were similar between the two groups. (3) Using the Kaplan-Meier and log-rank tests for the analysis of spermatogenesis, it was found that there was no significant difference in the first sperm appearance between the FGFR1 mutation group and the mutation-negative group (χ ² = 1.974, p=0.160). The median time of spermatogenesis in the FGFR1 mutation group was longer than that in the mutation-negative group, 16 months vs. 10 months, respectively. The cumulative spermatogenesis success rate at 12 months in the FGFR1 mutation group (35.71%) was lower than that in the mutation-negative group (68.75%) (p=0.047). The sperm concentration in the mutation-negative group was more easily achieved for different thresholds compared with that in the FGFR1 mutation group, but no significant difference was observed (p > 0.05) between the two groups. The last follow-up examination showed that the testicular volume was 7.00 (4.75-12.00) mL and 10.56 ± 4.82 mL (p=0.098), the ejaculate volume of sperm was 2.20 (1.40-2.26) mL and 3.06 ± 1.42 mL (p=0.175), and the sperm concentration was 7.19 (1.00-9.91) million/mL and 18.80 (4.58-53.62) million/mL (p=0.038) in the FGFR1 mutation and mutation-negative groups, respectively, while the sperm motility (A%, A + B%, and A + B + C%) was similar for the two groups (p=0.839, 0.909, and 0.759, respectively). The testosterone level during treatment was 366.02 ± 167.03 ng/dL and 362.27 ± 212.86 ng/dL in the FGFR1 mutation and mutation-negative groups, respectively (p=0.956).

CONCLUSION

Patients with FGFR1 mutations have a higher prevalence of cryptorchidism and smaller testicular volume. Although patients with FGFR1 mutations have a similar rate of success for spermatogenesis compared to that of the mutation-negative patients, a longer treatment period was required and a lower sperm concentration was achieved.

Management of Hypopituitarism

Hypopituitarism includes all clinical conditions that result in partial or complete failure of the anterior and posterior lobe of the pituitary gland’s ability to secrete hormones. The aim of management is usually to replace the target-hormone of hypothalamo-pituitary-endocrine gland axis with the exceptions of secondary hypogonadism when fertility is required, and growth hormone deficiency (GHD), and to safely minimise both symptoms and clinical signs. Adrenocorticotropic hormone deficiency replacement is best performed with the immediate-release oral glucocorticoid hydrocortisone (HC) in 2–3 divided doses. However, novel once-daily modified-release HC targets a more physiological exposure of glucocorticoids. GHD is treated currently with daily subcutaneous GH, but current research is focusing on the development of once-weekly administration of recombinant GH. Hypogonadism is targeted with testosterone replacement in men and on estrogen replacement therapy in women; when fertility is wanted, replacement targets secondary or tertiary levels of hormonal settings. Thyroid-stimulating hormone replacement therapy follows the rules of primary thyroid gland failure with L-thyroxine replacement. Central diabetes insipidus is nowadays replaced by desmopressin. Certain clinical scenarios may have to be promptly managed to avoid short-term or long-term sequelae such as pregnancy in patients with hypopituitarism, pituitary apoplexy, adrenal crisis, and pituitary metastases.

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

BACKGROUND

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

DISCUSSION

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

CONCLUSION

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

Predictive factors for pituitary response to pulsatile GnRH therapy in patients with congenital hypogonadotropic hypogonadism

Pulsatile gonadotropin-releasing hormone (GnRH) may induce spermatogenesis in most patients with congenital hypogonadotropic hypogonadism (CHH) by stimulating gonadotropin production, while the predictors for a pituitary response to pulsatile GnRH therapy were rarely investigated. Therefore, the aim of our study is to investigate predictors of the pituitary response to pulsatile GnRH therapy. This retrospective cohort study included 82 CHH patients who received subcutaneous pulsatile GnRH therapy for at least 1 month. Patients were categorized into poor or normal luteinizing hormone (LH) response subgroups according to their LH level (LH <2 IU l⁻¹ or LH ≥2 IU l⁻¹) 1 month into pulsatile GnRH therapy. Gonadotropin and testosterone levels, testicular size, and sperm count were compared between the two subgroups before and after GnRH therapy. Among all patients, LH increased from 0.4 ± 0.5 IU l⁻¹ to 7.5 ± 4.4 IU l⁻¹ and follicle-stimulating hormone (FSH) increased from 1.1 ± 0.9 IU l⁻¹ to 8.8 ± 5.3 IU l⁻¹. A Cox regression analysis showed that basal testosterone level (β = 0.252, P = 0.029) and triptorelin-stimulated FSH_60min (β = 0.518, P = 0.01) were two favorable predictors for pituitary response to GnRH therapy. Nine patients (9/82, 11.0%) with low LH response to GnRH therapy were classified into the poor LH response subgroup. After pulsatile GnRH therapy, total serum testosterone level was 39 ± 28 ng dl⁻¹ versus 248 ± 158 ng dl⁻¹ (P = 0.001), and testicular size was 4.0 ± 3.1 ml versus 7.9 ± 4.5 ml (P = 0.005) in the poor and normal LH response subgroups, respectively. It is concluded that higher levels of triptorelin-stimulated FSH_60minand basal total serum testosterone are favorable predictors of pituitary LH response to GnRH therapy.

Similarities and differences in the reproductive phenotypes of women with congenital hypogonadotrophic hypogonadism caused by GNRHR mutations and women with polycystic ovary syndrome

STUDY QUESTION

Does the phenotype of women with normosmic congenital hypogonadotrophic hypogonadism (nCHH) and pituitary resistance to GnRH caused by biallelic mutations in the GnRH receptor (GNRHR) (nCHH/bi-GNRHR) differ from that of women with polycystic ovary syndrome (PCOS)?

SUMMARY ANSWER

Women with nCHH/bi-GNRHR have variable pubertal development but nearly all have primary amenorrhea and an exaggerated LH response to GnRH stimulation, similar to that seen in women with PCOS.

WHAT IS KNOWN ALREADY

Women with nCHH/bi-GNRHR are very rare and their phenotype at diagnosis is not always adequately documented. The results of gonadotrophin stimulation by acute GnRH challenge test and ovarian features have not been directly compared between these patients and women with PCOS.

STUDY DESIGN, SIZE, DURATION

We describe the phenotypic spectrum at nCHH/bi-GNRHR diagnosis in a series of 12 women. Their reproductive characteristics and acute responses to GnRH were compared to those of 70 women with PCOS.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients and controls (healthy female volunteers aged over 18 years) were enrolled in a single French referral centre. Evaluation included clinical and hormonal studies, pelvic ultrasonography and GnRH challenge test. We also functionally characterized two missense GNRHR mutations found in two new consanguineous families.

MAIN RESULTS AND THE ROLE OF CHANCE

Breast development was highly variable at nCHH/bi-GNRHR diagnosis, but only one patient had undeveloped breasts. Primary amenorrhea was present in all but two cases. In untreated nCHH/bi-GNRHR patients, uterine height (UH) correlated (P = 0.01) with the circulating estradiol level and was shorter than in 23 nulliparous post-pubertal age-matched controls (P < 0.0001) and than in 15 teenagers with PCOS under 20-years-old (P < 0.0001) in which PCOS was revealed by primary amenorrhea or primary-secondary amenorrhea. Unexpectedly, the stimulated LH peak response in nCHH/bi-GNRHR patients was variable, and often normal or exaggerated. Interestingly, the LH peak response was similar to that seen in the PCOS patients, but the latter women had significantly larger mean ovarian volume (P < 0.001) and uterine length (P < 0.001) and higher mean estradiol (P < 0.001), anti-Müllerian hormone (AMH) (P = 0.02) and inhibin-B (P < 0.001) levels. In the two new consaguineous families, the affected nCHH/bi-GNRHR women carried the T269M or Y290F GNRHR missense mutation in the homozygous state. In vitro analysis of GnRHR showed complete or partial loss-of-function of the T269M and Y290F mutants compared to their wildtype counterpart.

LIMITATIONS, REASONS FOR CAUTION

The number of nCHH/bi-GNRHR patients reported here is small. As this disorder is very rare, an international study would be necessary to recruit a larger cohort and consolidate the phenotypic spectrum observed here.

WIDER IMPLICATIONS OF THE FINDINGS

In teenagers and young women with primary amenorrhea, significant breast and uterine development does not rule out CHH caused by biallelic GNRHR mutations. In rare patients with PCOS presenting with primary amenorrhea and a mild phenotype, the similar exaggerated pituitary LH responses to GnRH in PCOS and nCHH/bi-GNRHR patients could lead to diagnostic errors. This challenge test should therefore not be recommended. As indicated by consensus and guidelines, careful analysis of clinical presentation and measurements of testosterone circulating levels remain the basis of PCOS diagnosis. Also, analysis of ovarian volume, UH and of inhibin-B, AMH, estradiol and androgen circulating levels could help to distinguish between mild PCOS and nCHH/bi-GNRHR.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the French National Research Agency (ANR) grant ANR-09-GENO-017 KALGENOPATH, France; and by the Italian Ministry of Education, University and Research (MIUR) grant PRIN 2012227FLF_004, Italy. The authors declare no conflict of interest.

Optimal treatment for spermatogenesis in male patients with hypogonadotropic hypogonadism

BACKGROUND

To compare the efficacies of gonadotropin-releasing hormone (GnRH) pulse subcutaneous infusion with combined human chorionic gonadotropin and human menopausal gonadotropin (HCG/HMG) intramuscular injection have been performed to treat male hypogonadotropic hypogonadism (HH) spermatogenesis.

METHODS

In total, 220 idiopathic/isolated HH patients were divided into the GnRH pulse therapy and HCG/HMG combined treatment groups (n = 103 and n = 117, respectively). The luteinizing hormone and follicle-stimulating hormone levels were monitored in the groups for the 1st week and monthly, as were the serum total testosterone level, testicular volume and spermatogenesis rate in monthly follow-up sessions.

RESULTS

In the GnRH group and HCG/HMG group, the testosterone level and testicular volume at the 6-month follow-up session were significantly higher than were those before treatment. There were 62 patients (62/117, 52.99%) in the GnRH group and 26 patients in the HCG/HMG (26/103, 25.24%) group who produced sperm following treatment. The GnRH group (6.2 ± 3.8 months) had a shorter sperm initial time than did the HCG/HMG group (10.9 ± 3.5 months). The testosterone levels in the GnRH and HCG/HMG groups were 9.8 ± 3.3 nmol/L and 14.8 ± 8.8 nmol/L, respectively.

CONCLUSION

The GnRH pulse subcutaneous infusion successfully treated male patients with HH, leading to earlier sperm production than that in the HCG/HMG-treated patients. GnRH pulse subcutaneous infusion is a preferred method.

Paediatric and adult-onset male hypogonadism

The hypothalamic-pituitary-gonadal axis is of relevance in many processes related to the development, maturation and ageing of the male. Through this axis, a cascade of coordinated activities is carried out leading to sustained testicular endocrine function, with gonadal testosterone production, as well as exocrine function, with spermatogenesis. Conditions impairing the hypothalamic-pituitary-gonadal axis during paediatric or pubertal life may result in delayed puberty. Late-onset hypogonadism is a clinical condition in the ageing male combining low concentrations of circulating testosterone and specific symptoms associated with impaired hormone production. Testosterone therapy for congenital forms of hypogonadism must be lifelong, whereas testosterone treatment of late-onset hypogonadism remains a matter of debate because of unclear indications for replacement, uncertain efficacy and potential risks. This Primer focuses on a reappraisal of the physiological role of testosterone, with emphasis on the critical interpretation of the hypogonadal conditions throughout the lifespan of the male individual, with the exception of hypogonadal states resulting from congenital disorders of sex development.

GPR37 Signaling Modulates Migration of Olfactory Ensheathing Cells and Gonadotropin Releasing Hormone Cells in Mice

Gonadotropin releasing hormone (GnRH) neurons, part of the hypothalamic-pituitary-gonadal axis, regulate reproduction. Prenatally, GnRH neurons migrate into the brain from the nasal placode along terminal nerve fibers, intermixed with olfactory sensory axons and olfactory ensheathing cells (OECs). An expression analysis from embryonic GnRH neurons identified the G protein-coupled receptor 37 (GPR37 or PAEL-r). GPR37 has been linked to (1) juvenile Parkinson's disease in humans, (2) oligodendrocyte differentiation, and (3) Wnt/β-catenin signaling during neurogenesis. In this study, the role of GPR37 was investigated in the developing GnRH/olfactory system. PCR and immunocytochemistry confirmed expression of GPR37 in migrating GnRH neurons as well as in OECs. Inhibition of GPR37 signaling in nasal explants attenuated GnRH neuronal migration and OEC movement. Examination of GPR37 deficient mice revealed a decrease in the olfactory bulb nerve layer and attenuated/delayed maturation and migration of GnRH neurons into the brain. These data demonstrate a developmental role for GPR37 signaling in neural migration.

SIGNIFICANCE STATEMENT

Reproduction is controlled by gonadotrophin releasing hormone (GnRH) neurons located in the central nervous system. Embryonically, GnRH neurons originate in the nasal/olfactory placode and migrate into the brain on axonal tracks from cells in the vomeronasal organ, intermixed with olfactory sensory axons and olfactory ensheathing cells (OECs). An expression analysis from embryonic GnRH neurons identified the G protein-coupled receptor 37. Here we show that inhibition of GPR37 signaling in nasal explants and mutant mice attenuated GnRH neuronal migration. Signaling via GPR37 also perturbed OEC movement, resulting in a decrease in the olfactory bulb nerve layer in vivo. Together, these results identify a new role for GPR37 signaling during development - modulating cell migration.

Comparing the role of anti-Müllerian hormone as a marker of FSH action in male and female fertility

INTRODUCTION

Originally limited to the assessment of disorders of sex development, anti-Müllerian hormone (AMH) measurement has more recently been extended to several conditions affecting the reproductive axis in males and females. Follicle-stimulating hormone (FSH) regulation of gonadal function has been extensively studied, but its role on AMH production has been explored only recently.

AREAS COVERED

We addressed the relationship between FSH action on the gonads and the usefulness of AMH as a marker in conditions affecting the reproductive axis.

EXPERT OPINION

Sertoli cells are the most active cell population in the prepubertal testis. Serum AMH is an excellent marker of FSH action on Sertoli cell proliferation and function in patients with hypogonadotropic hypogonadism. Low serum AMH is expected to predict low sperm production and prompts initial FSH treatment followed by human chorionic gonadotropin (hCG) or luteinizing hormone (LH) addition. Gonadotropin treatment may be more effective if installed to mimic the postnatal activation stage of the hypothalamic-pituitary-testicular axis. In females, AMH secretion by small antral follicles is stimulated by FSH. Elevated AMH indicates increased follicle numbers and should be considered as a potential contraindication of gonadotropin treatment in infertile patients due to an increased risk of developing ovarian hyperstimulation syndrome.

Mutation profiles and clinical characteristics of Chinese males with isolated hypogonadotropic hypogonadism

OBJECTIVE

To investigate the mutation profiles and clinical characteristics of Chinese males with isolated hypogonadotropic hypogonadism (IHH) and discover new pathogenic genes that cause IHH.

DESIGN

A gene panel, including 31 known IHH genes and 52 candidate genes, was used to perform semiconductor next-generation sequencing.

SETTING

University hospital.

PATIENTS

One hundred thirty-eight sporadic male IHH patients and 10 IHH families; 100 healthy men with normal fertility served as control subjects.

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

Targeted next-generation sequencing, polymerase chain reaction and sequencing, pedigree analysis, and bioinformatics analysis.

RESULT(S)

Variants were distributed uniformly throughout 52 genes (52/83, 62.65%), including 16 (16/31, 51.61%) causal genes and 36 (36/52, 69.23%) candidate genes. Six new pathogenic variants and 52 likely pathogenic variants were identified in 16 genes known to cause nIHH/KS (normosmic IHH/Kallmann syndrome). In the 148 probands, PROKR2 (22/148, 14.86%), CHD7, FGFR1, and KAL1 had high mutation rates, and 8.78% (13/148) of the patients carried at least two variants in known genes. In addition, variants were identified in 36 candidate genes, and EGFR, ERBB4, PAX6, IGF1, SEMA4D, and SEMA7A should be prioritized for further research and genetic testing in IHH.

CONCLUSION(S)

The mutation frequency of IHH-causal genes in Chinese HAN males was different from the data reported in white populations. Oligogenic inheritance was a common phenomenon in IHH. Our study expands the mutation profile for IHH, and the new likely pathogenic genes identified in our study warrant further research in GnRH neuronal networks.

Gonadotropin-Induced Spermatogenesis in CHH Patients with Cryptorchidism

Congenital hypogonadotropic hypogonadism (CHH) patients with cryptorchidism history usually have poor spermatogenesis outcome, while researches focusing on this population are rare. This study retrospectively evaluated gonadotropin-induced spermatogenesis outcome in CHH patients with cryptorchidism (n = 40). One hundred and eighty-three CHH patients without cryptorchidism were served as control. All patients received combined gonadotropins therapy (HCG and HMG) and were followed up for at least 6 months. The median follow-up period was 24 (15, 33) months (totally 960 person-months). Sperm (>0/ml) initially appeared in semen at a median of estimated 24 months (95% confidence interval (CI) 17.8-30.2). Twenty (20/40, 50%) patients succeeded in producing sperms, and the average time to produce first sperm was 19 ± 8 months. Five pregnancies were achieved in 9 (5/9, 56%) couples who desired for children. Compared with CHH patients without cryptorchidism (n = 183), cryptorchid patients had longer median time for sperm appearance in semen (24 months vs. 15 months, P < 0.001), lower rate of spermatogenesis (50% vs. 67%, P=0.032), and lower mean sperm concentration (1.9 (0.5, 8.6) million/ml vs. 11.1(1.0, 25.0) million/ml, P=0.006) at the last visit. In conclusion, CHH patients with cryptorchidism require a longer period for gonadotropin-induced spermatogenesis. The successful rate and sperm concentration were lower than patients without cryptorchidism.

The Pulsatile Gonadorelin Pump Induces Earlier Spermatogenesis Than Cyclical Gonadotropin Therapy in Congenital Hypogonadotropic Hypogonadism Men

The objective of this study was to compare the effect of pulsatile gonadorelin pump (PGP) and cyclical gonadotropin (human chorionic gonadotropin [HCG]/human menopausal gonadotropin [HMG]) therapy (CGT) on spermatogenesis in congenital hypogonadotropic hypogonadism (CHH) men. Twenty-eight azoospermic CHH males were included in this nonrandomized study. Ten received PGP and 18 received CGT. The primary endpoint was the earliest time spermatogenesis occurred during 24 months of treatment. Spermatogenesis time was significant earlier in the PGP group than the CGT group (median of 6 and 14 months, respectively, χ² = 6.711, p = .01). Spermatogenesis occurred in 90% of the PGP group and 83.3% of the CGT group and showed statistically insignificant difference in the superiority analysis and the no-inferior test. Contributing factors significant for spermatogenesis were previous HCG/or testosterone treatment and the peak serum luteinizing hormone level of triptorelin stimulation test at baseline. Although testis volume and penile length increased significantly from baseline, the differences between the two therapies were not significant. There was a tendency for high serum testosterone level, associated with more facial acne and breast tenderness in the CGT group. Skin allergic erythema scleroma was a common side effect of the PGP. In summary, PGP resulted in earlier spermatogenesis and more desirable testosterone levels than CGT.

Recombinant Human FSH Treatment Outcomes in Five Boys With Severe Congenital Hypogonadotropic Hypogonadism

Context

Recombinant human FSH (r-hFSH), given to prepubertal boys with hypogonadotropic hypogonadism (HH), may induce Sertoli cell proliferation and thereby increase sperm-producing capacity later in life.

Objective

To evaluate the effects of r-hFSH, human chorionic gonadotropin (hCG), and testosterone (T) in such patients.

Design and Setting

Retrospective review in three tertiary centers in Finland between 2006 and 2016.

Patients

Five boys: ANOS1 mutation in two, homozygous PROKR2 mutation in one, FGFR1 mutation in one, and homozygous GNRHR mutation in one. Prepubertal testicular volume (TV) varied between 0.3 and 2.3 mL; three boys had micropenis, three had undergone orchidopexy.

Interventions

Two boys received r-hFSH (6 to 7 months) followed by r-hFSH plus hCG (33 to 34 months); one received T (6 months), then r-hFSH plus T (29 months) followed by hCG (25 months); two received T (3 months) followed by r-hFSH (7 months) or r-hFSH plus T (8 months).

Main Outcome Measures

TV, inhibin B, anti-Müllerian hormone, T, puberty, sperm count.

Results

r-hFSH doubled TV (from a mean ± SD of 0.9 ± 0.9 mL to 1.9 ± 1.7 mL; P < 0.05) and increased serum inhibin B (from 15 ± 5 ng/L to 85 ± 40 ng/L; P < 0.05). hCG further increased TV (from 2.1 ± 2.3 mL to 8.6 ± 1.7 mL). Two boys with initially extremely small testis size (0.3 mL) developed sperm (maximal sperm count range, 2.8 to 13.8 million/mL), which was cryopreserved.

Conclusions

Spermatogenesis can be induced with gonadotropins even in boys with HH who have extremely small testes, and despite low-dose T treatment given in early puberty. Induction of puberty with gonadotropins allows preservation of fertility.

New Biomarkers to Evaluate Hyperandrogenemic Women and Hypogonadal Men

Androgens can have variable effects on men and women. Women may be evaluated for androgen excess for several reasons. Typically, young premenopausal women present with clinical symptoms of hirsutism, alopecia, irregular menses, and/or infertility. The most common cause of these symptoms is polycystic ovary syndrome. After menopause, even though ovaries stop producing estrogen, they continue to produce androgen, and women can have new onset of hirsutism and alopecia. Laboratory evaluation involves measurement of the major ovarian and adrenal androgens. In women, age, phase of the menstrual cycle, menopausal status, obesity, metabolic health, and sex hormone-binding proteins significantly affect total-androgen levels and complicate interpretation. This review will summarize the clinically relevant evaluation of hyperandrogenemia at different life stages in women and highlight pitfalls associated with interpretation of commonly used hormone measurements. Hypogonadism in men is a clinical syndrome characterized by low testosterone and/or low sperm count. Symptoms of hypogonadism include decreased libido, erectile dysfunction, decreased vitality, decreased muscle mass, increased adiposity, depressed mood, osteopenia, and osteoporosis. Hypogonadism is a common disorder in aging men. Hypogonadism is observed rarely in young boys and adolescent men. Based on the defects in testes, hypothalamus, and/or pituitary glands, hypogonadism can be broadly classified as primary, secondary, and mixed hypogonadism. Diagnosis of hypogonadism in men is based on symptoms and laboratory measurement. Biomarkers in use/development for hypogonadism are classified as hormonal, Leydig and Sertoli cell function, semen, genetic/RNA, metabolic, microbiome, and muscle mass-related. These biomarkers are useful for diagnosis of hypogonadism, determination of the type of hypogonadism, identification of the underlying causes, and therapeutic assessment. Measurement of serum testosterone is usually the most important single diagnostic test for male hypogonadism. Patients with primary hypogonadism have low testosterone and increased luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Patients with secondary hypogonadism have low testosterone and low or inappropriately normal LH and FSH. This review provides an overview of hypogonadism in men and a detailed discussion of biomarkers currently in use and in development for diagnosis thereof.

Pulsatile gonadotropin-releasing hormone therapy is associated with earlier spermatogenesis compared to combined gonadotropin therapy in patients with congenital hypogonadotropic hypogonadism

Both pulsatile gonadotropin-releasing hormone (GnRH) infusion and combined gonadotropin therapy (human chorionic gonadotropin and human menopausal gonadotropin [HCG/HMG]) are effective to induce spermatogenesis in male patients with congenital hypogonadotropic hypogonadism (CHH). However, evidence is lacking as to which treatment strategy is better. This retrospective cohort study included 202 patients with CHH: twenty had received pulsatile GnRH and 182 had received HCG/HMG. Patients had received therapy for at least 12 months. The total follow-up time was 15.6 ± 5.0 months (range: 12–27 months) for the GnRH group and 28.7 ± 13.0 months (range: 12–66 months) for the HCG/HMG group. The median time to first sperm appearance was 6 months (95% confidence interval [CI]: 1.6–10.4) in the GnRH group versus 18 months (95% CI: 16.4–20.0) in the HCG/HMG group (P < 0.001). The median time to achieve sperm concentrations ≥5 × 10⁶ ml⁻¹ was 14 months (95% CI: 5.8–22.2) in the GnRH group versus 27 months (95% CI: 18.9–35.1) in the HCG/HMG group (P < 0.001), and the median time to concentrations ≥10 × 10⁶ ml⁻¹ was 18 months (95% CI: 10.0–26.0) in the GnRH group versus 39 months (95% CI unknown) in the HCG/HMG group. Compared to the GnRH group, the HCG/HMG group required longer treatment periods to achieve testicular sizes of ≥4 ml, ≥8 ml, ≥12 ml, and ≥16 ml. Sperm motility (a + b + c percentage) evaluated in semen samples with concentrations >1 × 10⁶ ml⁻¹ was 43.7% ± 20.4% (16 samples) in the GnRH group versus 43.2% ± 18.1% (153 samples) in the HCG/HMG group (P = 0.921). Notably, during follow-up, the GnRH group had lower serum testosterone levels than the HCG/HMG group (8.3 ± 4.6 vs 16.2 ± 8.2 nmol l⁻¹, P < 0.001). Our study found that pulsatile GnRH therapy was associated with earlier spermatogenesis and larger testicular size compared to combined gonadotropin therapy. Additional prospective randomized studies would be required to confirm these findings.

Divergent responses to kisspeptin in children with delayed puberty

BACKGROUND

The neuropeptide kisspeptin stimulates luteinizing hormone (LH) secretion in healthy adults but not in adults with idiopathic hypogonadotropic hypogonadism. We hypothesized that, in children presenting with delayed or stalled puberty, kisspeptin would elicit LH secretion in those children found on detailed nighttime neuroendocrine profiling to have evidence of emerging reproductive endocrine function.

METHODS

Eleven boys and four girls were admitted overnight to assess LH secretion at baseline, after a single intravenous bolus of kisspeptin, and after a single intravenous bolus of gonadotropin-releasing hormone (GnRH). Subjects then received exogenous pulsatile GnRH for 6 days and returned for a second visit to measure responses to kisspeptin and GnRH after this pituitary "priming." Responses to kisspeptin and GnRH were also measured in 5 healthy men.

RESULTS

Of the 15 children with delayed/stalled puberty, 6 exhibited at least one spontaneous LH pulse overnight; all of these subjects had clear responses to kisspeptin, as did one additional subject. Seven subjects had no response to kisspeptin, and one subject exhibited an intermediate response. In the children who responded to kisspeptin, the responses had features comparable to those of adult men.

CONCLUSION

In this first report of kisspeptin administration to pediatric subjects to our knowledge, children with delayed/stalled puberty showed a wide range of responses, with some showing a robust response and others showing little to no response. Further follow-up will determine whether responses to kisspeptin predict future pubertal entry for children with delayed puberty.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01438034 and NCT01952782.

FUNDING

NIH Eunice Kennedy Shriver National Institute of Child Health and Human Development (R01 HD043341, R01 HD090071, P50 HD028138), NIH National Center for Advancing Translational (UL1 TR001102), NIH National Institute of Diabetes and Digestive and Kidney Diseases (T32 DK007028), the Massachusetts General Hospital Executive Committee on Research Fund for Medical Discovery, Harvard Catalyst, Doris Duke Charitable Foundation (award 2013110), Charles H. Hood Foundation, Robert and Laura Reynolds MGH Research Scholar Program, and Harvard University. These funding sources had no role in the design of this study and did not have any role in conducting the study, analyses, interpretation of the data, or the decision to submit results.

Clinical and genetic features of 64 young male paediatric patients with congenital hypogonadotropic hypogonadism

CONTEXT

The diagnosis of congenital hypogonadotropic hypogonadism (CHH) in prepuberty has always been challenging. Here, we aimed at studying the clinical and genetic features of paediatric CHH, especially the phenotype of hypospadias and dual defects (patients showing hypothalamic and/or pituitary defects and testicular hypoplasia), so as to have a better understanding of CHH.

DESIGN

The clinical and genetic features of patients with CHH were analysed, and the relationships between hypospadias, dual defects and genetics were investigated.

PATIENTS

Patients who visited Beijing Children's Hospital and were positively diagnosed with CHH.

MEASUREMENTS

The collected data included sex hormones, MRI of the olfactory bulb, human chorionic gonadotrophin (hCG) test and genetic testing. We analysed clinical features and genetic results, especially hypospadias and dual defects, and compared the stimulated testosterone (T) levels in patients with and without cryptorchidism.

RESULTS

Sixty-four patients were positively diagnosed, and forty-seven (73.4%) had Kallmann syndrome (KS). Four patients (6.3%) had hypospadias, including 2 KS. Micropenis combined with cryptorchidism was the most common phenotype (39%). Approximately two-third of patients showed a poor response to hCG; 15 cases were diagnosed with dual defects, and there were no significant differences between those with and without cryptorchidism. Twenty-six cases (51%) of 51 patients were identified as having classical HH mutations, affecting 10 different genes, with oligogenic mutations in 5 cases (9.8%). The most common mutations were in PROKR2 (17.6%), FGFR1 (13.7%) and CHD7 (7.8%). The frequency of PROKR2 mutations was higher in dual HH when compared to other HH cases (6/15 vs 3/36, P = .021).

CONCLUSIONS

Micropenis and/or cryptorchidism can serve as important signs for the diagnosis of HH in paediatrics, and the coexistence of hypospadias does not exclude the diagnosis of CHH, including KS or normosmic isolated HH (nHH). Testicular function may be impaired earlier than expected, and PROKR2 mutations need to be evaluated to identify presumed dual defects.

Pulsatile GnRH Therapy May Restore Hypothalamus-Pituitary-Testis Axis Function in Patients With Congenital Combined Pituitary Hormone Deficiency: A Prospective, Self-Controlled Trial

CONTEXT

The effectiveness of pulsatile gonadotropin-releasing hormone (GnRH) therapy in patients with congenital combined pituitary hormone deficiency (CCPHD) has not been investigated because of the limited number of patients, as well as these patients' presumed pituitary hypoplasia, poor gonadotrophic cell reserve, and impaired gonadotrophic response to GnRH.

OBJECTIVE

To assess the pituitary response to pulsatile GnRH therapy in men with CCPHD.

DESIGN

Prospective, self-controlled, 3-month clinical trial.

SETTINGS

University endocrine clinic.

PATIENTS

Men with hypogonadotropic hypogonadism caused by CCPHD.

INTERVENTION

Pulsatile GnRH was administered subcutaneously for 3 months.

MAIN OUTCOME MEASURES

Primary endpoints were total serum testosterone, testicular volume, and luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels. Secondary endpoints included occurrence of spermatogenesis.

RESULTS

A total of 40 men with CCPHD completed the study. Of these, 60% (24 of 40) showed a good response to pulsatile GnRH treatment (response group). At 3 months, their LH and FSH levels increased to within the normal range and their testosterone levels increased to 8.67 ± 4.83 nmol/L. Of the patients in the response group, 33.3% (8 of 24) of them achieved spermatogenesis. The remaining 40% (16 of 40) of patients had a poor response to pulsatile GnRH treatment. Magnetic resonance imaging (MRI) did not reveal any correlation between pituitary response and pituitary height and/or integrity of the pituitary stalk.

CONCLUSIONS

This study suggests that gonadotrophs in patients with CCPHD can exist and be functional-even with MRI evidence of pituitary hypoplasia or dysplasia. Pulsatile GnRH therapy restored pituitary-testis axis function in 60% of patients with CCPHD. These results may directly guide the clinical therapeutic choice.

Targeted next generation sequencing approach identifies eighteen new candidate genes in normosmic hypogonadotropic hypogonadism and Kallmann syndrome

The genetic basis is unknown for ∼60% of normosmic hypogonadotropic hypogonadism (nHH)/Kallmann syndrome (KS). DNAs from (17 male and 31 female) nHH/KS patients were analyzed by targeted next generation sequencing (NGS) of 261 genes involved in hypothalamic, pituitary, and/or olfactory pathways, or suggested by chromosome rearrangements. Selected variants were subjected to Sanger DNA sequencing, the gold standard. The frequency of Sanger-confirmed variants was determined using the ExAC database. Variants were classified as likely pathogenic (frameshift, nonsense, and splice site) or predicted pathogenic (nonsynonymous missense). Two novel FGFR1 mutations were identified, as were 18 new candidate genes including: AMN1, CCKBR, CRY1, CXCR4, FGF13, GAP43, GLI3, JAG1, NOS1, MASTL, NOTCH1, NRP2, PALM2, PDE3A, PLEKHA5, RD3, and TRAPPC9, and TSPAN11. Digenic and trigenic variants were found in 8/48 (16.7%) and 1/48 (2.1%) patients, respectively. NGS with confirmation by Sanger sequencing resulted in the identification of new causative FGFR1 gene mutations and suggested 18 new candidate genes in nHH/KS.

Clinical Applications of Gonadotropins in the Male

The pituitary gonadotropins, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) play a pivotal role in reproduction. The synthesis and secretion of gonadotropins are regulated by complex interactions among several endocrine, paracrine, and autocrine factors of diverse chemical structure. In men, LH regulates the synthesis of androgens by the Leydig cells, whereas FSH promotes Sertoli cell function and thereby influences spermatogenesis. Gonadotropins are complex molecules composed of two subunits, the α- and β-subunit, that are noncovalently associated. Gonadotropins are decorated with glycans that regulate several functions of the protein including folding, heterodimerization, stability, transport, conformational maturation, efficiency of heterodimer secretion, metabolic fate, interaction with their cognate receptor, and selective activation of signaling pathways. A number of congenital and acquired abnormalities lead to gonadotropin deficiency and hypogonadotropic hypogonadism, a condition amenable to treatment with exogenous gonadotropins. Several natural and recombinant preparations of gonadotropins are currently available for therapeutic purposes. The difference between natural and the currently available recombinant preparations (which are massively produced in Chinese hamster ovary cells for commercial purposes) mainly lies in the abundance of some of the carbohydrates that conform the complex glycans attached to the protein core. Whereas administration of exogenous gonadotropins in patients with isolated congenital hypogonadotropic hypogonadism is a well recognized therapeutic approach, their role in treating men with normogonadotropic idiopathic infertility is still controversial. This chapter concentrates on the main structural and functional features of the gonadotropin hormones and how basic concepts have been translated into the clinical arena to guide therapy for gonadotropin deficit in males.