Kallmann syndrome: phenotype and genotype of hypogonadotropic hypogonadism

A comprehensive review of the new FIGO classification of ovulatory disorders

BACKGROUND

The World Health Organization (WHO) system for the classification of disorders of ovulation was produced 50 years ago and, by international consensus, has been updated by the International Federation of Gynecology and Obstetrics (FIGO).

OBJECTIVE AND RATIONALE

This review outlines in detail each component of the FIGO HyPO-P (hypothalamic, pituitary, ovarian, PCOS) classification with a concise description of each cause, and thereby provides a systematic method for diagnosis and management.

SEARCH METHODS

We searched the published articles in the PubMed database in the English-language literature until October 2022, containing the keywords ovulatory disorders; ovulatory dysfunction; anovulation, and each subheading in the FIGO HyPO-P classification. We did not include abstracts or conference proceedings because the data are usually difficult to assess.

OUTCOMES

We present the most comprehensive review of all disorders of ovulation, published systematically according to the logical FIGO classification.

WIDER IMPLICATIONS

Improving the diagnosis of an individual's ovulatory dysfunction will significantly impact clinical practice by enabling healthcare practitioners to make a precise diagnosis and plan appropriate management.

A novel mutation in ANOS1 in a Chinese family with Kallmann syndrome: Case report

We reported a novel variant in Kallmann syndrome. It not only determines the clinical importance of whole exome sequencing for identification of genetic pathogenic variants, but also enriches the ANOS1 genetic spectrum of CHH patients in Chinese population.

Illuminating the terminal nerve: Uncovering the link between GnRH-1 neuron and olfactory development

During embryonic development, the olfactory placode (OP) generates migratory neurons, including olfactory pioneer neurons, cells of the terminal nerve (TN), gonadotropin-releasing hormone-1 (GnRH-1) neurons, and other uncharacterized neurons. Pioneer neurons from the OP induce olfactory bulb (OB) morphogenesis. In mice, GnRH-1 neurons appear in the olfactory system around mid-gestation and migrate via the TN axons to different brain regions. The GnRH-1 neurons are crucial in controlling the hypothalamic-pituitary-gonadal axis. Kallmann syndrome is characterized by impaired olfactory system development, defective OBs, secretion of GnRH-1, and infertility. The precise mechanistic link between the olfactory system and GnRH-1 development remains unclear. Studies in humans and mice highlight the importance of the prokineticin-2/prokineticin-receptor-2 (Prokr2) signaling pathway in OB morphogenesis and GnRH-1 neuronal migration. Prokr2 loss-of-function mutations can cause Kallmann syndrome (KS), and hence the Prokr2 signaling pathway represents a unique model to decipher the olfactory/GnRH-1 connection. We discovered that Prokr2 is expressed in the TN neurons during the critical period of GnRH-1 neuron formation, migration, and induction of OB morphogenesis. Single-cell RNA sequencing identified that the TN is formed by neurons distinct from the olfactory neurons. The TN neurons express multiple genes associated with KS. Our study suggests that the aberrant development of pioneer/TN neurons might cause the KS spectrum.

Shared features in ear and kidney development - implications for oto-renal syndromes

The association between ear and kidney anomalies has long been recognized. However, little is known about the underlying mechanisms. In the last two decades, embryonic development of the inner ear and kidney has been studied extensively. Here, we describe the developmental pathways shared between both organs with particular emphasis on the genes that regulate signalling cross talk and the specification of progenitor cells and specialised cell types. We relate this to the clinical features of oto-renal syndromes and explore links to developmental mechanisms.

Syndromic and Monogenic Obesity: New Opportunities Due to Genetic-Based Pharmacological Treatment

Obesity is a significant health problem with a continuously increasing prevalence among children and adolescents that has become a modern pandemic during the last decades. Nowadays, the genetic contribution to obesity is well-established. For this narrative review article, we searched PubMed and Scopus databases for peer-reviewed research, review articles, and meta-analyses regarding the genetics of obesity and current pharmacological treatment, published in the English language with no time restrictions. We also screened the references of the selected articles for possible additional articles in order to include most of the key recent evidence. Our research was conducted between December 2022 and December 2023. We used the terms "obesity", "genetics", "monogenic", "syndromic", "drugs", "autosomal dominant", "autosomal recessive", "leptin-melanocortin pathway", and "children" in different combinations. Recognizing the genetic background in obesity can enhance the effectiveness of treatment. During the last years, intense research in the field of obesity treatment has increased the number of available drugs. This review analyzes the main categories of syndromic and monogenic obesity discussing current data on genetic-based pharmacological treatment of genetic obesity and highlighting the necessity that cases of genetic obesity should follow specific, pharmacological treatment based on their genetic background.

Digenic CHD7 and SMCHD1 inheritance Unveils phenotypic variability in a family mainly presenting with hypogonadotropic hypogonadism

Objectives

CHARGE syndrome is a congenital hereditary condition involving multiple systems. Patients are easily misdiagnosed with idiopathic hypogonadotropic hypogonadism (IHH) due to the overlap of clinical manifestations. An accurate clinical diagnosis remains challenging when the predominant clinical manifestation resembles hypogonadotropic hypogonadism.

Methods

This original research is conducted based on the genetic finding and analysis of clinical cases. Whole-exome sequencing (WES) and in-silico analyse were performed on two sisters to investigate the pathogenesis in this family. Homology modelling was conducted to evaluate structural changes in the variants.

Results

WES and Sanger sequencing revealed two siblings carrying a nonsense mutation (NM_017780.4: c.115C > T) in exon 2 of CHD7 inherited from a mildly affected mother and a missense mutation (NM_015295.3: c.2582T > C) in exon 20 of SMCHD1 inherited from an asymptomatic father. The nonsense mutation in CHD7 was predicted to generate nonsense-mediated decay, whereas the missense mutation in SMCHD1 decreased protein stability.

Conclusions

We identified digenic CHD7 and SMCHD1 mutations in IHH-associated diseases for the first time and verified the synergistic role of oligogenic inheritance. It was also determined that WES is an effective tool for distinguishing diseases with overlapping features and establishing a molecular diagnosis for cases with digenic or oligogenic hereditary disorders, which is beneficial for timely treatment, and family genetic counseling.

Environmental and Genetic Traffic in the Journey from Sperm to Offspring

Recent advancements in the understanding of how sperm develop into offspring have shown complex interactions between environmental influences and genetic factors. The past decade, marked by a research surge, has not only highlighted the profound impact of paternal contributions on fertility and reproductive outcomes but also revolutionized our comprehension by unveiling how parental factors sculpt traits in successive generations through mechanisms that extend beyond traditional inheritance patterns. Studies have shown that offspring are more susceptible to environmental factors, especially during critical phases of growth. While these factors are broadly detrimental to health, their effects are especially acute during these periods. Moving beyond the immutable nature of the genome, the epigenetic profile of cells emerges as a dynamic architecture. This flexibility renders it susceptible to environmental disruptions. The primary objective of this review is to shed light on the diverse processes through which environmental agents affect male reproductive capacity. Additionally, it explores the consequences of paternal environmental interactions, demonstrating how interactions can reverberate in the offspring. It encompasses direct genetic changes as well as a broad spectrum of epigenetic adaptations. By consolidating current empirically supported research, it offers an exhaustive perspective on the interwoven trajectories of the environment, genetics, and epigenetics in the elaborate transition from sperm to offspring.

Investigation of subfertility in the female Nsmf knockout mouse

OBJECTIVE

To study if a pituitary or ovarian defect contributes to subfertility of the female Nsmf knockout (KO) mouse, an animal model of the hypogonadotropic hypogonadism gene NSMF.

DESIGN

Analysis of hypothalamic, pituitary and ovarian gene expression at baseline, serum gonadotropin levels before and after gonadotropin-releasing hormone (GnRH) stimulation, ovarian response and implantation after superovulation, gonadotropin effects after ovariectomy, and ovarian NSMF protein expression.

SETTING

University research laboratory.

PATIENTS

None; mice were used.

INTERVENTIONS

Gonadotropin-releasing hormone stimulation, superovulation, and ovariectomy in separate experiments.

MAIN OUTCOME MEASURES

Gene expression in the hypothalamus, pituitary, and ovary; ovarian response and implantation after superovulation; serum gonadotropins after GnRH stimulation and ovariectomy; Western blot to measure ovarian NSMF expression.

RESULTS

We found increased hypothalamic Kiss1, Gnrh1, and Jak2 mRNA expression in female Nsmf KO vs. wild type (WT) mice. However, pituitary gonadotropin, and GnRH receptor gene expression was not affected, and serum gonadotropin levels were normal. Gonadotropins increased after ovariectomy for both groups. Baseline Kiss1, Fshr, Prkaca, Prkar1a, and Gdf9 ovarian mRNA expression was increased and Cyp19a1 expression was decreased in Nsmf KO mice, while superovulated Nsmf KO mice had reduced ovarian Kiss1r, Prkar1a, and Fshr mRNA expression, 50% less oocytes, and normal implantation. Western blot demonstrated NSMF protein expression in the ovary of WT mice.

CONCLUSIONS

Altered hypothalamic and ovarian gene expression was demonstrated in female Nsmf KO mice. It is possible that increased hypothalamic Gnrh1 and Kiss1 mRNA expression could compensate for reduced NSMF enabling a normal pituitary gonadotropin response. Impaired superovulation response, altered ovarian gene expression, and decreased number of oocytes indicate ovarian dysfunction, but a uterine factor cannot be excluded. These findings provide an anatomic basis for future mechanistic studies of subfertility in female Nsmf KO mice.

The genetic background of female reproductive disorders: a systematic review

PURPOSE OF REVIEW

Reproductive function is the interplay between environmental factors and the genetic footprint of each individual. The development in genetic analysis has strengthened its role in the investigation of female reproductive disorders, potential treatment options and provision of personalized care. Despite the increasing requirement of genetic testing, the evidence of the gene-disease relationships (GDR) is limited. We performed a systematic review exploring the associations between the most frequent female reproductive endocrine disorders associated with subfertility [including polycystic ovaries syndrome (PCOS), premature ovarian failure (POI) and hypogonadotropic hypogonadism] and their genetic background in order to summarize current knowledge.

METHODS

A systematic review of relevant literature in accordance with PRISMA guidelines was conducted until July 2022. Data sources that were used are PubMed and Embase.

RECENT FINDINGS

A total of 55 studies were included from the 614 articles identified in the original search. We identified 384 genes associated with one or more of the included female reproductive disorders. The highest number of genes was found to be associated with POI ( N  = 209), followed by hypogonadotropic hypogonadism ( N  = 88) and PCOS ( N  = 87). Four genes, including FSHR , LHβ , LEPR and SF1 were associated with multiple reproductive disorders implying common pathways in the development of those diseases.

SUMMARY

We provide an up-to-date summary of the currently known genes that are associated with three female reproductive disorders (PCOS, POI and hypogonadotropic hypogonadism). The role of genetic analysis in the field of impaired female reproduction may have a role in the diagnosis of female reproductive disorders and personalized patient care.

Clinical Manifestations, Genetic Variants and Therapeutic Evaluation in Sporadic Chinese Patients with Idiopathic Hypogonadotropic Hypogonadism

Purpose

Genetic factors account for a large proportion of idiopathic hypogonadotropic hypogonadism (IHH) etiologies, although not necessarily a complete genetic basis. This study aimed to characterize the clinical presentations, genetic variants, and therapeutic outcomes of patients with sporadic IHH, which may be helpful for genetic counseling and treatment decisions.

Patients and Methods

Eleven Chinese patients with IHH were retrospectively analyzed. Rare genetic variants were evaluated using whole-exome sequencing and bioinformatics analysis and were further classified according to the ACMG-AMP guidelines. The therapeutic responses of patients were further evaluated.

Results

Six heterozygous variants of SOX10, WDR11, PROKR2, CHD7 and FGF17 were detected in five Kallmann syndrome (KS) patients, whereas two heterozygous variants of CHD7 and PROKR2 were detected in two normosmic IHH (nIHH) patients. Among these variants, a novel likely pathogenic variant in the SOX10 (c.429-1G>C) was considered to cause the KS phenotype in patient 02, and two potential variants of uncertain significance (VUS) in CHD7 (c.3344G>A and c.7391A>G) possibly contributed to the KS phenotype in patient 05 and the nIHH phenotype in patient 07, which need to be confirmed by further evidence. Additionally, long-term testosterone or estradiol replacement treatment effectively improved the development of sexual characteristics in patients with IHH.

Conclusion

Next-generation sequencing is a powerful tool for identifying the molecular etiology and early diagnosis of IHH. Efficient therapeutic outcomes strongly indicate a need for timely treatment.

A Literature Review and a Proposed Classification of the Relationships between Ovulatory Infertility and Lifestyle Factors Based on the Three Groups of Ovulation Disorders Classified by WHO

Ovulatory infertility is a serious clinical problem whose direct causes are still largely unknown. In addition to pathologies that make it impossible for a couple to establish a pregnancy, there are a number of other factors that have a bearing on fertility, including lifestyle factors, and particularly diet. Although numerous studies have been performed linking such factors to ovulatory infertility, most of them lack the necessary clinical significance, instead focusing on observational data and suggesting or establishing associative relationships. This article consists of a literature review focusing on connections between lifestyle factors such as diet, physical exercise, oxidative stress, sleep, and supplementation, and ovulatory infertility. Special emphasis was given to issues such as obesity and insulin resistance and their mutual relationship with other factors linked to ovulatory infertility. In addition, based on the conclusions of the literature review, the authors have proposed a classification of relationships between ovulation disorders and lifestyle factors in ovulatory infertility within the framework of the WHO classification of ovulation disorders. Furthermore, areas that merit further research have been indicated as well as those that do not. WHO Group II disorders gained prominence in the results of the study as the number of links with lifestyle factors and ovulatory infertility found in the course of the review greatly exceeded those for Groups I and III. The data presented in the article show that the issues of proper diet and physical exercise are those that could benefit from robust clinical studies focused specifically on ovulation infertility, while studies concerning the relationship between oxidative stress, sleep, and supplementation and ovulatory infertility do not seem to be promising directions as far as clinical significance is concerned.

Illuminating the Terminal Nerve: Uncovering the Link between GnRH-1 and Olfactory Development

During embryonic development, the olfactory placode (OP) generates migratory neurons, including olfactory pioneer neurons, cells of the terminal nerve (TN), Gonadotropin-releasing hormone-1 (GnRH-1) neurons, and other uncharacterized neurons. Pioneer neurons from the olfactory placode induce olfactory bulb morphogenesis. In mice, GnRH-1 neurons appear in the olfactory system around mid-gestation and migrate via the terminal nerve axons to different brain regions. The GnRH-1 neurons are crucial in controlling the hypothalamic-pituitary-gonadal (HPG) axis. Kallmann syndrome is characterized by impaired olfactory system development, defective olfactory bulbs, defective secretion of GnRH-1, and infertility. The precise mechanistic link between the olfactory system and GnRH-1 development remains unclear. Studies in humans and mice highlight the importance of the Prokineticin-2/Prokineticin-Receptor-2 (Prokr2) signaling pathway in olfactory bulb morphogenesis and GnRH-1 neuronal migration. Prokr2 loss-of-function mutations can cause Kallmann syndrome, and hence the Prokr2 signaling pathway represents a unique model to decipher the olfactory/GnRH-1 connection. We discovered that Prokr2 is expressed in the TN neurons during the critical period of GnRH-1 neuron formation, migration, and induction of olfactory bulb morphogenesis. Single-cell RNA sequencing identified that the TN is formed by neurons that are distinct from the olfactory neurons. The TN neurons express multiple genes associated with KS. Our study suggests that the aberrant development of pioneer/TN neurons might cause the KS spectrum.

Key Points

1) Pioneer or terminal nerve neurons play a crucial role in initiating the development of the olfactory bulbs. We found that the Prokineticin Receptor-2 gene, associated with Kallmann syndrome, is expressed by the olfactory pioneer/terminal nerve neurons.2) We genetically traced, isolated, and conducted Single-cell RNA sequencing on terminal nerve neurons of rodents. This analysis revealed a significant enrichment of gene expression related to Kallmann syndrome.3) Our study indicates that the investigation of Pioneer/terminal nerve neurons should be a pivotal focal point for comprehending developmental defects affecting olfactory and GnRH-1 systems.

Bibliometric analysis of scientific publications on cryptorchidism: Research hotspots and trends between 2000 and 2022

Background

Cryptorchidism is defined as failure of unilateral or bilateral testicular descent, which increases the risk of infertility and testicular carcinoma. Although there is much research on cryptorchidism, few studies have used the bibliometric analysis method. The purpose of this study was to conduct a comprehensive analysis of cryptorchidism from muti-dimensional perspectives to summarize the research hotspots and trends in cryptorchidism research.

Methods

Relevant studies on cryptorchidism were retrieved from the Web of Science Core Collection (WoSCC) database from 2000 to 2022. A comprehensive bibliometric analysis of cryptorchidism was performed by using the CiteSpace, Tableau Public, and VOSviewer software, including the annual distributions of publications, countries, authors, institutions, journals, references, and keywords.

Results

From January 1st, 2000 to May 17th, 2022, a total of 5023 papers concerning cryptorchidism were identified for analysis. The USA contributed the most publications (n = 1193) in this field, and the annual number of publications rose rapidly in China. The University of Melbourne published the largest number of papers (n = 131). "Hutson, John M." was the most core author ranked by publications (n = 51), and "Skakkebaek, Niels E." enjoyed the largest number of citations (4441). The JOURNAL OF UROLOGY published the largest number of papers (n = 225), while the average citations per publication of the 75 papers in HUMAN REPRODUCTION reached 62.38. Additionally, burstness analysis of references and keywords showed that cryptorchidism research was mainly focused on the exploration of the optimal mode of treatment for cryptorchidism, including hypogonadism such as Kallmann syndrome and Klinefelter syndrome.

Conclusion

Cryptorchidism has attracted continuous attention from the scientific community concerned. International collaboration in the field has witnessed significant growth in recent years and remains essential to further enhance collaborative efforts between scholars from different countries. In addition, the exploration of the optimal treatment modality for cryptorchidism, especially in the prevention of adult infertility, remains a major focus of future research. High-quality follow-up studies are also needed in the future. The pathogenesis (especially at the genetic level) and treatment of hypogonadism such as Kallmann syndrome and Klinefelter syndrome have attracted increasing attention recently, which may usher in some breakthroughs in coming years.

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.

A clinical case of identical twins with hypogonadotropic hypogonadism, primary empty sella syndrome and identified rare CHD7 gene variant

Key Clinical Message

Empty sella syndrome is a complex syndrome with a diverse clinical presentation. The combination with functional hypogonadotropic hypogonadism is a real challenge for the clinician. Mutations in the CHD7 gene could be a possible, yet unproven, cause of "empty sella" syndrome. Patients with hypogonadotropic hypogonadism should be examined for possible CHD7 mutations, even if they do not have any CHARGE syndrome characteristics.

Abstract

Empty sella is an anatomo-radiological finding characterized by arachnoid herniation into the sellar fossa with reduction of pituitary volume and/or pituitary stalk compression). We report a clinical case of 35-year-old identical male twins, admitted to the clinic of endocrinology and metabolic diseases with history of infertility, hormonal constellation of hyposomatotropism and hypogonadotropic hypogonadism. The patients presented with hyposmia. Magnetic resonance imaging (MRI) of the hypothalamic-pituitary region revealed the presence of partial empty sella. CHD7 gene variant was observed on genetic testing. CHD7 gene mutation was considered as a possible reason for the presence of central hypogonadism and yet unproven genetic cause of "empty sella" syndrome.

Reconsidering the olfactory and brain structures in Kallmann's syndrome: New findings in the analysis of volumetry

OBJECTIVE

Kallmann's syndrome (KS) is characterized by hypogonadotropic hypogonadism and olfactory disorders. The complementary exams for evaluating of patients with hypogonadotrophic hypogonadism are important for the diagnosis and management of these patients.

PATIENTS

We performed a well-established olfactory Sniffin' Stick test (SST) on 17 adult patients with KS and brain magnetic resonance imaging (MRI) to evaluate olfactory structures and further analysis by Freesurfer, a software for segmentation and volumetric evaluation of brain structures. We compared the Freesurfer results with 34 healthy patients matched for age and sex and performed correlations between the data studied.

RESULTS

More than half of the patients with KS reported preserved smell but had olfactory disorders in the SST. In the MRI, 16 patients showed changes in the olfactory groove, the olfactory bulb-tract complex was altered in all of them and 52% had symmetrical structural changes. Interestingly, the pituitary gland was normal in only 29%. Regarding correlations, symmetrical changes in the olfactory structures were related to anosmia in 100%, while asymmetric changes induced anosmia in only 50% (p = .0294). In Freesurfer's assessment, patients with KS, compared to controls, had lower brainstem volume. In those with aplastic anterior olfactory sulcus, the brainstem volume was lower than in hypoplasia (p = .0333).

CONCLUSIONS

Olfactory assessment and MRI proved to be important auxiliary tools for the diagnosis and management of patients with KS. New studies are needed to confirm the decrease in brainstem volume found by the Freesurfer software in patients with KS. Further studies are needed to confirm the decrease in brainstem volume found by the Freesurfer software in patients with KS.

Anosmia: Brighton Collaboration case definition and guidelines for data collection, analysis, and presentation of immunization safety data

This is a Brighton Collaboration case definition of anosmia to be used in the evaluation of adverse events following immunization, and for epidemiologic studies for the assessment of background incidence or hypothesis testing. The case definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of SARS-CoV-2 vaccines. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and defined levels of certainty, after an exhaustive review of the literature and expert consultation. The document underwent peer review by the Brighton Collaboration Network and by two expert reviewers prior to submission.

Mutation spectrum of Kallmann syndrome: identification of five novel mutations across ANOS1 and FGFR1

BACKGROUND

Kallmann syndrome (KS) is a common type of idiopathic hypogonadotropic hypogonadism. To date, more than 30 genes including ANOS1 and FGFR1 have been identified in different genetic models of KS without affirmatory genotype-phenotype correlation, and novel mutations have been found.

METHODS

A total of 35 unrelated patients with clinical features of disorder of sex development were recruited. Custom-panel sequencing or whole-exome sequencing was performed to detect the pathogenic mutations. Sanger sequencing was performed to verify single-nucleotide variants. Copy number variation-sequencing (CNV-seq) was performed to determine CNVs. The pathogenicity of the identified variant was predicted in silico. mRNA transcript analysis and minigene reporter assay were performed to test the effect of the mutation on splicing.

RESULTS

ANOS1 gene c.709 T > A and c.711 G > T were evaluated as pathogenic by several commonly used software, and c.1063-2 A > T was verified by transcriptional splicing assay. The c.1063-2 A > T mutation activated a cryptic splice acceptor site downstream of the original splice acceptor site and resulted in an aberrant splicing of the 24-basepair at the 5' end of exon 8, yielding a new transcript with c.1063-1086 deletion. FRFR1 gene c.1835delA was assessed as pathogenic according to the ACMG guideline. The CNV of del(8)(p12p11.22)chr8:g.36140000_38460000del was judged as pathogenic according to the ACMG & ClinGen technical standards.

CONCLUSIONS

Herein, we identified three novel ANOS1 mutations and two novel FGFR1 variations in Chinese KS families. In silico prediction and functional experiment evaluated the pathogenesis of ANOS1 mutations. FRFR1 c.1835delA mutation and del(8)(p12p11.22)chr8:g.36140000_38460000del were assessed as pathogenic variations. Therefore, our study expands the spectrum of mutations associated with KS and provides diagnostic evidence for patients who carry the same mutation in the future.

Clinical and Biochemical Characteristics of Male Idiopathic Hypogonadotropic Hypogonadism Patients: A Retrospective Cross Sectional Study

BACKGROUND

Idiopathic hypogonadotropic hypogonadism (IHH) is a medical condition where there is a deficiency or insensitivity of gonadotropin-releasing hormone (GnRH) without a known cause. Not only are the sexual characteristics of a person affected by this condition but also are the psychological and physical development, thus necessitating its early recognition and treatment. This research was carried out to identify the laboratory parameters and to present symptoms of the patients with complaints of IHH.

MATERIALS AND METHODS

This retrospective, center, single-center, cross-sectional study was carried out in Aga Khan University from December 2000 until December 2020 on the patients that presented to the clinic with IHH. The patients included in the study were those that presented with hypogonadism, a low concentration of sex steroid hormone, and an abnormal gonadotropin level without any expansive pituitary or hypothalamic lesion.

RESULTS

Seventy nine patients presenting with IHH were included with their mean age of 24.2 ± 7.5 years. Of these, 64 (81.0%) had genital atrophy, 50 (63.6%) showed an absence of secondary sexual characteristics, 53 (67.1%) complained of infertility, 44 (55.7%) had not shown signs of puberty, 52 (65.8%) had erectile dysfunction, 46 (58.2%) had a decrease in libido, 11(13.9%) had a previous familial history, 24 (30.3%) had gynecomastia, 9 (11.4%) had non-descended testes, and 6 (7.6%) had anosmia. These patients had serum testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels of 26.3 ± 60, 1.3 ± 2.4, and 2.7 ± 5.0 (IU/L), respectively.

CONCLUSION

Thus, it can be stated that small genitalia is the most common complaint among patients with IHH, followed by infertility and lack of secondary sexual characteristics. The testosterone level in serum is also found to be low among these patients.

Case report: A case of Culler-Jones syndrome caused by a novel mutation of GLI2 gene and literature review

Culler-Jones syndrome is a rare clinical phenomenon with diverse manifestations and is prone to misdiagnosis. We report one patient who presented with a 10-year history of anosmia and a 1-year history of epididymal pain. Kallmann syndrome was suspected initially. The results of his laboratory tests, imaging, and genetic testing, however, combined to provide a conclusive diagnosis of Culler-Jones syndrome. With the aid of high-throughput sequencing technology, the GLI2 gene c.527A>G (p.Tyr176Cys) heterozygous mutation in the child was identified. No published works have yet described this mutation site. We described Culler-Jones syndrome in a child at length. We recommend that Culler-Jones syndrome be taken into account when considering the spectrum of disorders associated with abnormal growth and development in children. Once diagnosed, individualized hormone replacement treatment is required for each patient.

An Indonesian male with congenital hypogonadotropic hypogonadism: A case report and literature review

Introduction

Congenital hypogonadotropic hypogonadism (CHH) is a rare disorder caused by insufficient gonadotropin-releasing hormone (GnRH) production.

Case presentation

An Indonesian adolescent, 22 years old, Javanese ethnic, complained of a small penis, low sexual desire, fatigue, and anosmia since childhood. Medical history stated that the patient had low testosterone levels 7 years ago and received testosterone once. Testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were decreased. The testicular ultrasound result was bilateral microtestis, suspicious of bilateral hypoplasia of the epididymis. Brain MRI also supports the diagnosis of hypogonadotropic hypogonadism, and the patient received Sustanon of 250 mg/2 weeks. The patient showed a good prognosis after 1 month of therapy.

Discussion

The success of CHH therapy must be explored to improve its management.

Conclusion

CHH in an Indonesian male shows a good prognosis with testosterone injection.

•

CHH diagnosis is difficult to confirm in low-resource settings.

•

Testosterone induction is a classic CHH therapy.

•

CHH has a poor prognosis.

Genetics of pubertal delay

The timing of pubertal development is strongly influenced by the genetic background, and clinical presentations of delayed puberty are often found within families with clear patterns of inheritance. The discovery of the underlying genetic regulators of such conditions, in recent years through next generation sequencing, has advanced the understanding of the pathogenesis of disorders of pubertal timing and the potential for genetic testing to assist diagnosis for patients with these conditions. This review covers the significant advances in the understanding of the biological mechanisms of delayed puberty that have occurred in the last two decades.

Male Idiopathic Hypogonadotropic Hypogonadism: Serum Insulin-like Growth Factor-1 and Oestradiol Levels

Background

Idiopathic hypogonadotropic hypogonadism (IHH) is a form of male infertility caused by a congenital defect in the secretion or action of gonadotropin-releasing hormone from the hypothalamus. Oestradiol emerged as the main sex steroid in the regulation of the hypothalamic-pituitary-testicular axis, reproductive function and growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis in men. Moreover, GH/IGF-1 axis has been suggested to play a role in IHH.

Aims

This study evaluated serum IGF-1 in IHH men and controls. Furthermore, we evaluated the association between serum total oestradiol (TE2) and IGF-1 levels in patients and controls. Parameters including age, body mass index and fertility history were analysed.

Settings and Design

This prospective study was conducted at the Royan institute.

Materials and Methods

In 20 men with IHH and 20 controls, serum IGF-1 levels were estimated using chemiluminescence immunoassay and serum E2 levels were assessed by means of the electrochemiluminescence method.

Statistical Analysis Used

Kolmogorov-Smirnov test, parametric t-test or the Mann-Whitney and the Pearson correlation coefficient were performed. SPSS version 22 was used for the analysis of data.

Results

There was a significant decrease in serum IGF-1 levels in IHH patients compared with controls (145.1 ± 8.9 ng/ml vs. 229.6 ± 7.3 ng/ml P < 0.001, respectively). Furthermore, a significant decrease was observed in TE2 levels in IHH male patients (12.3 ± 2.5 pg/ml) compared with controls (31.9 ± 5.3 pg/ml P < 0.001). A positive correlation was observed between serum IGF-1 and TE2 levels in the total number of participants, suggesting that E2 deficiency in IHH cases can explain the lower levels of serum IGF-1.

Conclusions

These findings suggest that the reduction in IGF-1 levels may be associated with the influence of E2 on the GH/IGF-1 axis, and may confirm the role of the GH/IGF-1 axis in IHH. Further investigations will be required to determine the exact mechanisms by which E2 and IGF-1 affect the reproductive neuroendocrine function.

Hypogonadism in Males With Genetic Neurodevelopmental Syndromes

Genetic syndromes that affect the nervous system may also disrupt testicular function, and the mechanisms for these effects may be interrelated. Most often neurological signs and symptoms predominate and hypogonadism remains undetected and untreated, while in other cases, a thorough evaluation of a hypogonadal male reveals previously unrecognized ataxia, movement disorder, muscle weakness, tremor, or seizures, leading to a syndromic diagnosis. Androgen deficiency in patients with neurological diseases may aggravate muscle weakness and fatigue and predispose patients to osteoporosis and obesity. The purpose of this mini review is to provide a current understanding of the clinical, biochemical, histologic, and genetic features of syndromes in which male hypogonadism and neurological dysfunction may coexist and may be encountered by the clinical endocrinologist.

Genetics of Obesity in Humans: A Clinical Review

Obesity is a complex multifactorial disorder with genetic and environmental factors. There is an increase in the worldwide prevalence of obesity in both developed and developing countries. The development of genome-wide association studies (GWAS) and next-generation sequencing (NGS) has increased the discovery of genetic associations and awareness of monogenic and polygenic causes of obesity. The genetics of obesity could be classified into syndromic and non-syndromic obesity. Prader–Willi, fragile X, Bardet–Biedl, Cohen, and Albright Hereditary Osteodystrophy (AHO) syndromes are examples of syndromic obesity, which are associated with developmental delay and early onset obesity. Non-syndromic obesity could be monogenic, polygenic, or chromosomal in origin. Monogenic obesity is caused by variants of single genes while polygenic obesity includes several genes with the involvement of members of gene families. New advances in genetic testing have led to the identification of obesity-related genes. Leptin (LEP), the leptin receptor (LEPR), proopiomelanocortin (POMC), prohormone convertase 1 (PCSK1), the melanocortin 4 receptor (MC4R), single-minded homolog 1 (SIM1), brain-derived neurotrophic factor (BDNF), and the neurotrophic tyrosine kinase receptor type 2 gene (NTRK2) have been reported as causative genes for obesity. NGS is now in use and emerging as a useful tool to search for candidate genes for obesity in clinical settings.

Treatment of congenital hypogonadotropic hypogonadism in male patients

Congenital hypogonadotropic hypogonadism (CHH) is characterized by complete or partial failure of pubertal development because of inadequate secretion of gonadotropic hormones. CHH consists of hypogonadotropic hypogonadism with anosmia or hyposmia, Kallmann syndrome, and the normosmic variation normosmic idiopathic hypogonadotropic hypogonadism. CHH is one of the few treatable diseases of male infertility, although men with primary testicular dysfunction have irreversibly diminished spermatogenic capacity. The approach to CHH treatment is determined by goals such as developing virilization or inducing fertility. This review focuses on the current knowledge of therapeutic modalities for inducing puberty and fertility in men with CHH.

Novel Genomic Variants, Atypical Phenotypes and Evidence of a Digenic/Oligogenic Contribution to Disorders/Differences of Sex Development in a Large North African Cohort

In a majority of individuals with disorders/differences of sex development (DSD) a genetic etiology is often elusive. However, new genes causing DSD are routinely reported and using the unbiased genomic approaches, such as whole exome sequencing (WES) should result in an increased diagnostic yield. Here, we performed WES on a large cohort of 125 individuals all of Algerian origin, who presented with a wide range of DSD phenotypes. The study excluded individuals with congenital adrenal hypoplasia (CAH) or chromosomal DSD. Parental consanguinity was reported in 36% of individuals. The genetic etiology was established in 49.6% (62/125) individuals of the total cohort, which includes 42.2% (35/83) of 46, XY non-syndromic DSD and 69.2% (27/39) of 46, XY syndromic DSD. No pathogenic variants were identified in the 46, XX DSD cases (0/3). Variants in the AR, HSD17B3, NR5A1 and SRD5A2 genes were the most common causes of DSD. Other variants were identified in genes associated with congenital hypogonadotropic hypogonadism (CHH), including the CHD7 and PROKR2. Previously unreported pathogenic/likely pathogenic variants (n = 30) involving 25 different genes were identified in 22.4% of the cohort. Remarkably 11.5% of the 46, XY DSD group carried variants classified as pathogenic/likely pathogenic variant in more than one gene known to cause DSD. The data indicates that variants in PLXNA3, a candidate CHH gene, is unlikely to be involved in CHH. The data also suggest that NR2F2 variants may cause 46, XY DSD.

ANOS1 variants in a large cohort of Chinese patients with congenital hypogonadotropic hypogonadism

OBJECTIVES

Congenital hypogonadotropic hypogonadism (CHH) is a rare congenital gonadal dysplasia caused by defects in the synthesis, secretion or signal transduction of hypothalamic gonadotropin releasing hormone. The main manifestations of CHH are delayed or lack puberty, low levels of sex hormones and gonadotropins, and may be accompanied with other clinical phenotypes. Some patients with CHH are also accompanied with anosmia or hyposmia, which is called Kalman syndrome (KS). ANOS1, located on X chromosome, is the first gene associated with CHH in an X-linked recessive manner. This study aims to provide a basis for the genetic diagnosis of CHH by analyzing the gene variant spectrum of ANOS1 in CHH and the relationship between clinical phenotype and genotype.

METHODS

In this study, whole exome sequencing (WES) was used to screen rare sequencing variants (RSVs) of ANOS1 in a Chinese cohort of 165 male CHH patients. Four commonly used in silico tools were used to predict the function of the identified RSVs in coding region, including Polyphen2, Mutation Taster, SIFT, and Combined Annotation Dependent Depletion (CADD). Splice Site Prediction by Neural Network (NNSPLICE) was employed to predict possibilities of intronic RSVs to disrupt splicing. American College of Medical Genetics and Genomics (ACMG) guidelines was used to assess the pathogenicity of the detected RSVs. The ANOS1 genetic variant spectrum of CHH patients in Chinese population was established. The relationship between clinical phenotype and genotype was analyzed by collecting detailed clinical data.

RESULTS

Through WES analysis for 165 CHH patients, ANOS1 RSVs were detected in 17 of them, with the frequency of 10.3%. A total of 13 RSVs were detected in the 17 probands, including 5 nonsense variants (p.T76X, p.R191X, p.W257X, p.R262X, and p.W589X), 2 splicing site variants (c.318+3A>C, c.1063-1G>C), and 6 missense variants (p.N402S, p.N155D, p.P504L, p.C157R, p.Q635P, and p.V560I). In these 17 CHH probands with ANOS1 RSVs, many were accompanied with other clinical phenotypes. The most common associated phenotype was cryptorchidism (10/17), followed by unilateral renal agenesis (3/17), dental agenesis (3/17), and synkinesia (3/17). Eight RSVs, including p.T76X, p.R191X, p.W257X, p.R262X, p.W589X, c.318+3A>C, c.1063-1G>C, and p.C157R, were predicted to be pathogenic or likely pathogenic ANOS1 RSVs by ACMG. Eight CHH patients with pathogenic or likely pathogenic ANOS1 variants had additional features. In contrast, only one out of nine CHH patients with non-pathogenic (likely benign or uncertain of significance) ANOS1 variants according to ACMG exhibited additional features. And function of the non-pathogenic ANOS1 variants accompanied with other CHH-associated RSVs.

CONCLUSIONS

The ANOS1 genetic spectrum of CHH patients in Chinese population is established. Some of the correlations between clinical phenotype and genotype are also established. Our study indicates that CHH patients with pathogenic or likely pathogenic ANOS1 RSVs tend to exhibit additional phenotypes. Although non-pathogenic ANOS1 variants only may not be sufficient to cause CHH, they may function together with other CHH-associated RSVs to cause the disease.

Olfactory Radioanatomical Findings in Patients With Cardiac Arrhythmias, COVID-19, and Healthy Controls

Background

Clinical hyposmia and anosmia are commonly seen, most frequently with either post-inflammatory, age-related, or idiopathic causes being most frequent. Actual anatomical abnormalities of the olfactory groove or olfactory bulb are far less common. A recent case report showing a possible link between congenital olfactory bulb agenesis and Wolff-Parkinson-White syndrome suggested that there may be a relationship between cardiac arrhythmia and olfactory bulb development. While Kallmann syndrome (KS) is the classic syndrome involving olfactory bulb agenesis and hypogonadotropic hypogonadism, this case report and a prior report noting isolated hypogonadotropic hypogonadism and the Wolff-Parkinson-White syndrome suggest there may be more rare associations between cardiac arrhythmia and olfactory groove abnormalities.

Methods

A retrospective study was conducted to attempt to elucidate whether there may be a link between cardiac arrhythmias and olfactory anatomical abnormalities. The olfactory bulb volume (OBV) and olfactory sulcus depth (OSD) of 44 patients with cardiac arrhythmias were compared to 43 healthy control patients. Additionally, 11 patients with acute COVID-19 were also compared in those groups. Patients were seen between September and December 2020. Available MRI images were utilized.

Results

The average right and left olfactory bulb volume was 29.42±18.17 mm³ and 25.67±15.29 mm³ for patients with cardiac arrhythmia, 40.79±30.65 mm³ and 38.95±21.87mm³ for healthy controls, and 21.30±15.23 mm³ and 17.75±9.63 mm³ for COVID-19 patients. The average right and left olfactory sulcus depth was 7.68±1.31 mm and 7.47±1.56 mm for patients with cardiac arrhythmia, 10.67±1.53 mm and 10.62±1.67 mm for controls, and 7.91±0.99 mm and 8.02±0.88 mm for COVID-19 patients. The right and left olfactory bulb volume difference versus controls was significant for cardiac arrhythmia patients (p=0.028 and p=0.0038) and for COVID-19 patients (p=0.047 and p=0.0029), and the right and left olfactory sulcus depth difference versus controls was significant for cardiac arrhythmia patients (p<0.0001 and p<0.0001) and for COVID-19 patients (p<0.0001 and p<0.0001). Both COVID-19 and cardiac arrhythmia patients were, on average, significantly older than controls. On multivariate analysis, cardiac arrhythmia or COVID-19 diagnosis did not significantly correlate with smaller olfactory bulb volume, but older age, cardiac arrhythmia diagnosis, and COVID-19 diagnosis did significantly correlate with smaller olfactory sulcus depth. On multivariate analysis, older age was significantly correlated with cardiac arrhythmia diagnosis and COVID-19 diagnosis.

Conclusions

Olfactory bulb volume and olfactory sulcus depth in both cardiac arrhythmia and COVID-19 patients appeared significantly smaller than in controls. Cardiac arrhythmia and COVID-19 patients were significantly older than controls. Age, as well as genetic predisposition, may contribute to a difference in the radiographic olfactory anatomical findings in patients with cardiac arrhythmias and COVID-19.

46,XY disorders of sex development: the use of NGS for prevalent variants

46,XY disorders of sex development (DSD) present with diverse phenotypes and complicated genetic causes. Precise genetic diagnosis contributes to accurate management, and targeted next-generation sequencing (NGS) and whole-exome sequencing are powerful tools for investigating DSD. However, the prevalent variants resulting in 46,XY DSD remain unclear, especially those associated with mild forms, such as isolated hypospadias, inguinal cryptorchidism, and micropenis. From 2019 to 2021, 74 patients with 46,XY DSD (48 typical and 26 mild) from the First Affiliated Hospital of Sun Yat-sen University were enrolled in our cohort study for targeted NGS or whole-exome sequencing. Our targeted 46,XY DSD panel included 108 genes involved in disorders of gonadal development and differentiation, steroid hormone synthesis and activation, persistent Müllerian duct syndrome, idiopathic hypogonadotropic hypogonadism, syndromic disorder, and others. Variants were classified as pathogenic, likely pathogenic, variant of uncertain significance, likely benign, or benign following the American College of Medical Genetics guidelines. As a result, 28 of 74 (37.8%) patients with pathogenic and/or likely pathogenic variants acquired genetic diagnoses. The Mild DSD patients acquired a diagnosis rate of 30.7%. We detected 44 variants in 28 DSD genes from 31 patients, including 33 novel and 11 reported variants. Heterozygous (65%) and missense (70.5%) variants were the most common. Variants associated with steroid hormone synthesis and activation were the main genetic causes of 46,XY DSD. In conclusion, 46,XY DSD manifests as a series of complicated polygenetic diseases. NGS reveals prevalent variants and improves the genetic diagnoses of 46,XY DSD, regardless of severity.

When anorexia nervosa symptoms mask Kallmann syndrome

BACKGROUND

Although anorexia nervosa might delay puberty, a structured assessment at its onset remains crucial in excluding congenital delayed puberty diseases.

CASE PRESENTATION

During the follow-up of a 15-year-old girl suffering from anorexia nervosa, a change of treatment has led to a thorough medical history revealing the absence of the olfactory bulb. Kallmann syndrome diagnosis was made on a blood analysis and the patient was treated with a multidisciplinary approach.

CONCLUSION

After the diagnosis, our patient was relieved as it has clarified some of her symptoms including anosmia, poor height and maturational delay. Too often a delayed puberty is attributed to anorexia nervosa itself without considering medical history. This case definitely shows the importance of performing a case history and early diagnosis in pre-pubertal AN to rule out other rare diseases and avoid mid- and long-term sequelae.

LEVEL OF EVIDENCE

IV (case study).

The evaluation of ovarian function in normosmic idiopathic hypogonadotropic hypogonadism with a fibroblast growth factor receptor 1 mutation: a case report

Normosmic idiopathic hypogonadotropic hypogonadism (nIHH) is a rare disorder with pubertal delay, normal sense of smell. nIHH with a fibroblast growth factor receptor 1 mutation is much more common in adult males but is rarely reported in females. In addition, the assessment and monitoring of ovarian function in nIHH females has often been ignored. We report a 24-year-old nIHH female with the complaint of primary amenorrhea and delayed secondary sexual traits development. Whole-Exome Sequencing analysis revealed a novel mutation in the third exon of fibroblast growth factor receptor 1 gene (c.289 G > A), which resulted in the replacement of glycine acid with serine. Then the patient was recommended to start with the hormone therapy (HT). After several months of estrogen combined with progesterone replacement, the patient had regular menstruation. The breast development and genital development gradually became Tanner stage 5. Anti-Müllerian hormones (AMHs) were also evaluated and the serum AMH level keeps fluctuating within the normal reference range. We highlight the great variability of fibroblast growth factor receptor 1 mutation phenotypes and the evaluation of ovarian reserve in nIHH, and the hormone replacement therapy is necessary to improve secondary sexual development for patients with nIHH.

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.

Anosmin-1-Like Effect of UMODL1/Olfactorin on the Chemomigration of Mouse GnRH Neurons and Zebrafish Olfactory Axons Development

The impairment of development/migration of hypothalamic gonadotropin-releasing hormone (GnRH) neurons is the main cause of Kallmann's syndrome (KS), an inherited disorder characterized by hypogonadism, anosmia, and other developmental defects. Olfactorin is an extracellular matrix protein encoded by the UMODL1 (uromodulin-like 1) gene expressed in the mouse olfactory region along the migratory route of GnRH neurons. It shares a combination of WAP and FNIII repeats, expressed in complementary domains, with anosmin-1, the product of the ANOS1 gene, identified as the causative of KS. In the present study, we have investigated the effects of olfactorin in vitro and in vivo models. The results show that olfactorin exerts an anosmin-1-like strong chemoattractant effect on mouse-immortalized GnRH neurons (GN11 cells) through the activation of the FGFR and MAPK pathways. In silico analysis of olfactorin and anosmin-1 reveals a satisfactory similarity at the N-terminal region for the overall arrangement of corresponding WAP and FNIII domains and marked similarities between WAP domains’ binding modes of interaction with the resolved FGFR1–FGF2 complex. Finally, in vivo experiments show that the down-modulation of the zebrafish z-umodl1 gene (orthologous of UMODL1) in both GnRH3:GFP and omp2k:gap-CFPrw034 transgenic zebrafish strains leads to a clear disorganization and altered fasciculation of the neurites of GnRH3:GFP neurons crossing at the anterior commissure and a significant increase in olfactory CFP + fibers with altered trajectory. Thus, our study shows olfactorin as an additional factor involved in the development of olfactory and GnRH systems and proposes UMODL1 as a gene worthy of diagnostic investigation in KS.

Classification of CHD7 Rare Variants in Chinese Congenital Hypogonadotropic Hypogonadism Patients and Analysis of Their Clinical Characteristics

Purpose:CHD7 rare variants can cause congenital hypogonadotropic hypogonadism (CHH) and CHARGE syndrome. We aimed to summarize the genotype and phenotype characteristics of CHH patients with CHD7 rare variants.

Methods: Rare sequencing variants (RSVs) were detected by Sanger sequencing in a series of 327 CHH patients and were interpreted and grouped according to the American College of Medical Genetics and Genomics (ACMG) guideline. Detailed phenotyping and genotype-phenotype correlation were analyzed.

Results: The RSV detection rate was 11.01% (36/327) in the CHH patients. We identified 30 RSVs and 19 of them were novel. Following ACMG criteria, three variants were pathogenic (P), 4 were likely pathogenic (LP), 3 were of uncertain significance with paradoxical evidence (US1), and 20 were of uncertain significance without enough evidence (US2). All patients (4/4, 100%) with P or LP variants manifested extragonadal symptoms.

Conclusion: Addition of 19 novel CHD7 variants expanded the spectrum of variants, and pathogenic or likely pathogenic RSVs were more likely to cause syndromic CHH. For CHH patients carrying CHD7 RSVs, detailed genotyping and phenotyping can facilitate clinical diagnosis and therapy.

The NDNF-like factor Nord is a Hedgehog-induced extracellular BMP modulator that regulates Drosophila wing patterning and growth

Hedgehog (Hh) and Bone Morphogenetic Proteins (BMPs) pattern the developing Drosophila wing by functioning as short- and long-range morphogens, respectively. Here, we show that a previously unknown Hh-dependent mechanism fine-tunes the activity of BMPs. Through genome-wide expression profiling of the Drosophila wing imaginal discs, we identify nord as a novel target gene of the Hh signaling pathway. Nord is related to the vertebrate Neuron-Derived Neurotrophic Factor (NDNF) involved in congenital hypogonadotropic hypogonadism and several types of cancer. Loss- and gain-of-function analyses implicate Nord in the regulation of wing growth and proper crossvein patterning. At the molecular level, we present biochemical evidence that Nord is a secreted BMP-binding protein and localizes to the extracellular matrix. Nord binds to Decapentaplegic (Dpp) or the heterodimer Dpp-Glass-bottom boat (Gbb) to modulate their release and activity. Furthermore, we demonstrate that Nord is a dosage-dependent BMP modulator, where low levels of Nord promote and high levels inhibit BMP signaling. Taken together, we propose that Hh-induced Nord expression fine-tunes both the range and strength of BMP signaling in the developing Drosophila wing.

Identification and Functional Characterization of a Novel Variant in the SEMA3A Gene in a Chinese Family with Kallmann Syndrome

BACKGROUND

Kallmann syndrome (KS) is a rare genetic disease characterized by the reproductive system and olfactory dysplasia due to the defective migration of gonadotropin-releasing hormone (GnRH) neurons. However, this disorder is clinically heterogeneous and the genotype-phenotype relationship has not been determined.

OBJECTIVE

The present study aimed to identify the variant causing KS in a Chinese family and evaluate the functional consequences and phenotypes associated with the novel variant.

METHODS

A Chinese family with KS was screened for pathogenic variants by whole-exome sequencing (WES). Bioinformatic analysis was performed to predict the consequences of the identified variant. The expression of the mutant protein was examined in vitro.

RESULTS

A novel heterozygous variant (NM_006080.2 : c.814G > T) in SEMA3A was identified in the patient and his father, which caused the substitution of aspartic acid with tyrosine in codon 272. It was predicted to result in pathogenic significance with a high damaging score and seriously affect protein structure by bioinformatic analysis. In vitro experiments revealed this variant could significantly decrease the expression of SEMA3A. Furthermore, it may cause the disease by failing to induce the phosphorylation of focal adhesion kinase (FAK) in GnRH neurons.

CONCLUSION

Identification and functional characterization of this novel variant in the SEMA3A gene in a Chinese family with Kallmann syndrome extend the genetic variant spectrum of SEMA3A and provide more data about the heterogeneity of KS, which may provide further insights into the diagnosis of KS and help patients get additional data in genetic counseling and timely treatment.

New findings in oligogenic inheritance of congenital hypogonadotropic hypogonadism

INTRODUCTION

Congenital hypogonadotropic hypogonadism results from a dysfunction of the hypothalamic-pituitary-gonadal axis, which is essential for the development and function of the reproductive system. It may be associated with anosmia, referred to as Kallmann syndrome, or a normal sense of smell. Numerous studies have proven that hypogonadotropic hypogonadism is not simply a monogenic Mendelian disease, but that more than one gene may be involved in its pathogenesis in a single patient. The oligogenic complex architecture underlying the disease is still largely unknown.

MATERIAL AND METHODS

Targeted next-generation sequencing (NGS) was used to screen for DNA variants in a cohort of 47 patients with congenital hypogonadotropic hypogonadism. The NGS panel consists of over 50 well-known and candidate genes, associated with hypogonadotropic state.

RESULTS

Here we report the identification of new oligogenic variants in SPRY4/SEMA3A, SRA1/SEMA7A, CHD7/SEMA7A, CCDC141/POLR3B/POLR3B, and PROKR2/SPRY4/NSMF. These genes are known to contribute to the phenotype of hypogonadotropic hypogonadism, yet our results point to potential new "partners" underlying digenic and trigenic patterns.

CONCLUSIONS

The finding supports the importance of oligogenic inheritance and demonstrates the complexity of genetic architecture in hypogonadotropic hypogonadism. It also underlines the necessity for developing fine-tuned guidelines to provide a tool for adequate and precise sequence variant classification in non-Mendelian conditions.

The diagnostic value of the olfactory evaluation for congenital hypogonadotropic hypogonadism

OBJECTIVE

The aim of this study was to evaluate the diagnostic accuracy of different olfactory evaluation tools in congenital hypogonadotropic hypogonadism (CHH) patients.

METHODS

Seventy-one CHH patients were prospectively recruited at Peking Union Medical College Hospital between November 2020 and July 2021. The Chinese Olfactory Function Test (COFT) and Self-reported Olfactory Scale (SROS) were adapted as the subjective tools for the evaluation of olfactory function, and magnetic resonance imaging of olfactory apparatus (MRI-OA) was the objective tool. The olfactory bulb volume (OBV) and the olfactory sulcus depth (OSD) were quantified.

RESULTS

Based on the COFT, 36 patients were categorized as having normosmic CHH (nCHH), and the other 35 patients were categorized as having Kallmann syndrome (KS). Among nCHH patients, 35 patients were classified as having normal olfaction and 1 patient had abnormal olfaction by SROS. For KS patients, there were 30 patients grouped into abnormal olfaction, while 5 patients had normal olfaction by SROS. For MRI-OA, 67% (18/27) of nCHH patients showed normal olfactory apparatus, and 33% (9/27) showed bilateral or unilateral olfactory bulb aplasia or hypoplasia. Among KS patients, 96% (27/28) of patients showed bilateral olfactory bulb hypoplasia or aplasia, and 4% (1/28) of patients showed normal olfactory apparatus. All six patients with unilateral olfactory bulb aplasia and three patients with bilateral olfactory bulb aplasia showed normal olfactory function. The accuracy of the SROS in the diagnosis of nCHH and KS was 91.5%, with a sensitivity of 0.857 and a specificity of 0.972, while the accuracy of MRI-OA is 92.7%, with a sensitivity of 0.964 and a specificity of 0.889.

CONCLUSION

SROS and MRI-OA both showed high accuracy to distinguish between KS and nCHH. The abnormal structure of the olfactory apparatus was relatively common in nCHH patients. CHH patients with unilateral olfactory bulb aplasia dysplasia usually had normal olfaction. Normal olfaction without apparent olfactory bulbs is rare but occurred in male CHH patients.

Endocrinopathies and Male Infertility

Male infertility is approaching a concerning prevalence worldwide, and inflicts various impacts on the affected couple. The hormonal assessment is a vital component of male fertility evaluation as endocrine disorders are markedly reversible causatives of male infertility. Precise hormonal regulations are prerequisites to maintain normal male fertility parameters. The core male reproductive event, spermatogenesis, entails adequate testosterone concentration, which is produced via steroidogenesis in the Leydig cells. Physiological levels of both the gonadotropins are needed to achieve normal testicular functions. The hypothalamus-derived gonadotropin-releasing hormone (GnRH) is considered the supreme inducer of the gonadotropins and thereby the subsequent endocrine reproductive events. This hypothalamic–pituitary–gonadal (HPG) axis may be modulated by the thyroidal or adrenal axis and numerous other reproductive and nonreproductive hormones. Disruption of this fine hormonal balance and their crosstalk leads to a spectrum of endocrinopathies, inducing subfertility or infertility in men. This review article will discuss the most essential endocrinopathies associated with male factor infertility to aid precise understanding of the endocrine disruptions-mediated male infertility to encourage further research to reveal the detailed etiology of male infertility and perhaps to develop more customized therapies for endocrinopathy-induced male infertility.

A recessive PRDM13 mutation results in congenital hypogonadotropic hypogonadism and cerebellar hypoplasia

The positive regulatory (PR) domain containing 13 (PRDM13) putative chromatin modifier and transcriptional regulator functions downstream of the transcription factor PTF1A, which controls GABAergic fate in the spinal cord and neurogenesis in the hypothalamus. Here, we report a recessive syndrome associated with PRDM13 mutation. Patients exhibited intellectual disability, ataxia with cerebellar hypoplasia, scoliosis, and delayed puberty with congenital hypogonadotropic hypogonadism (CHH). Expression studies revealed Prdm13/PRDM13 transcripts in the developing hypothalamus and cerebellum in mouse and human. An analysis of hypothalamus and cerebellum development in mice homozygous for a Prdm13 mutant allele revealed a significant reduction in the number of Kisspeptin (Kiss1) neurons in the hypothalamus and PAX2+ progenitors emerging from the cerebellar ventricular zone. The latter was accompanied by ectopic expression of the glutamatergic lineage marker TLX3. Prdm13-deficient mice displayed cerebellar hypoplasia and normal gonadal structure, but delayed pubertal onset. Together, these findings identify PRDM13 as a critical regulator of GABAergic cell fate in the cerebellum and of hypothalamic kisspeptin neuron development, providing a mechanistic explanation for the cooccurrence of CHH and cerebellar hypoplasia in this syndrome. To our knowledge, this is the first evidence linking disrupted PRDM13-mediated regulation of Kiss1 neurons to CHH in humans.

A novel heterozygous mutation of CHD7 gene in a Chinese patient with Kallmann syndrome: a case report

BACKGROUND

Variants of chromodomain helicase DNA binding protein 7 (CHD7) gene are commonly associated with Kallmann syndrome (KS) and account for 5-6% of idiopathic hypogonadotropic hypogonadism (IHH) cases. Here we report a novel mutation of CHD7 gene in a patient with KS, which may contribute to the better understanding of KS.

CASE PRESENTATION

A 29-year-old male patient with KS and a chief complaint of delayed puberty for 13 years (Tanner B Stage< 4) was admitted to the Department of Endocrinology of the First Affiliated Hospital of Zhejiang University (Hangzhou, China) in September 2019. Dual-energy X-ray absorptiometry (DEXA) showed low bone density in both lumbar spine (L1 ~ L5 mean Z-score - 3.0) and femoral neck (Z-score - 2.7). Dynamic contrast-enhanced magnetic resonance imaging (MRI) of pituitary and contrast-enhanced computed tomography (CT) showed no abnormal findings. Ophthalmological evaluation showed that his both eyes showed exotropia, and no sight loss was noted. Heterozygous c.1619G > T mutation of TCD7 gene (p.G4856V) was detected, whereas none of his family members had this mutation. Human chorionic gonadotropin (HCG) and human menopausal gonadotropin (HMG) were injected for three times/week to treat idiopathic hypogonadotropic hypogonadism (IHH). After several months of therapy, the patient's health condition improved. His testicles became larger, and his secondary sexual characteristics improved after treatment.

CONCLUSION

Exploration of the novel splice-site mutation of CHD7 may further our current understanding of KS.

Oligogenic Inheritance Underlying Incomplete Penetrance of PROKR2 Mutations in Hypogonadotropic Hypogonadism

The role of the prokineticin 2 pathway in human reproduction, olfactory bulb morphogenesis, and gonadotropin-releasing hormone secretion is well established. Recent studies have highlighted the implication of di/oligogenic inheritance in this disorder. In the present study, we aimed to identify the genetic mechanisms that could explain incomplete penetrance in hypogonadotropic hypogonadism (HH). This study involved two unrelated Tunisian patients with HH, which was triggered by identifying a homozygous p.(Pro290Ser) mutation in the PROKR2 gene in a girl (HH1) with Kallmann syndrome (KS). The functional effect of this variant has previously been well demonstrated. Unexpectedly, her unaffected father (HH1P) and brother (HH1F) also carried this genetic variation at a homozygous state. In the second family, we identified a heterozygous p.(Lys205del) mutation in PROKR2, both in a male patient with normosmic idiopathic IHH (HH12) and his asymptomatic mother. Whole-exome sequencing in the three HH1 family members allowed the identification of additional variants in the prioritized genes. We then carried out digenic combination predictions using the oligogenic resource for variant analysis (ORVAL) software. For HH1, we found the highest number of disease-causing variant pairs. Notably, a CCDC141 variant (c.2803C > T) was involved in 18 pathogenic digenic combinations. The CCDC141 variant acts in an autosomal recessive inheritance mode, based on the digenic effect prediction data. For the second patient (HH12), prediction by ORVAL allowed the identification of an interesting pathogenic digenic combination between DUSP6 and SEMA7A genes, predicted as “dual molecular diagnosis.” The SEMA7A variant p.(Glu436Lys) is novel and predicted as a VUS by Varsome. Sanger validation revealed the absence of this variant in the healthy mother. We hypothesize that disease expression in HH12 could be induced by the digenic transmission of the SEMA7A and DUSP6 variants or a monogenic inheritance involving only the SEMA7A VUS if further functional assays allow its reclassification into pathogenic. Our findings confirm that homozygous loss-of-function genetic variations are insufficient to cause KS, and that oligogenism is most likely the main transmission mode involved in Congenital Hypogonadotropic Hypogonadism.

The Differential Roles for Neurodevelopmental and Neuroendocrine Genes in Shaping GnRH Neuron Physiology and Deficiency

Gonadotropin releasing hormone (GnRH) neurons are hypothalamic neuroendocrine cells that control sexual reproduction. During embryonic development, GnRH neurons migrate from the nose to the hypothalamus, where they receive inputs from several afferent neurons, following the axonal scaffold patterned by nasal nerves. Each step of GnRH neuron development depends on the orchestrated action of several molecules exerting specific biological functions. Mutations in genes encoding for these essential molecules may cause Congenital Hypogonadotropic Hypogonadism (CHH), a rare disorder characterized by GnRH deficiency, delayed puberty and infertility. Depending on their action in the GnRH neuronal system, CHH causative genes can be divided into neurodevelopmental and neuroendocrine genes. The CHH genetic complexity, combined with multiple inheritance patterns, results in an extreme phenotypic variability of CHH patients. In this review, we aim at providing a comprehensive and updated description of the genes thus far associated with CHH, by dissecting their biological relevance in the GnRH system and their functional relevance underlying CHH pathogenesis.

Optimizing the Diagnostic Accuracy and Treatment Decisions in Men with Testosterone Deficiency

OBJECTIVE

This narrative review offers a guideline-based approach to optimizing the diagnostic evaluation and treatment decision-making in men being evaluated for testosterone deficiency.

METHODS

A narrative review RESULTS: Testosterone deficiency is a clinical syndrome that results from the inability of the testes to produce normal amounts of testosterone, and is characterized by a constellation of symptoms and signs associated with consistently low testosterone concentrations. The diagnosis of testosterone deficiency is made by ascertainment of symptoms and signs; measurement of total and, if indicated, free testosterone levels, in early morning fasting samples on 2 or more days; measurement of LH and FSH to distinguish primary from secondary hypogonadism; and additional evaluation to ascertain the cause of testosterone deficiency. Non-specificity of symptoms and signs; variations in testosterone levels over time; inaccuracy in the measurement of total and free testosterone levels; variations in binding protein concentrations; and the suboptimal reference ranges contribute to diagnostic inaccuracy. Testosterone treatment is indicated for men with symptomatic testosterone deficiency. Testosterone treatment should be avoided in men with prostate or breast cancer, erythrocytosis, thrombophilia, increased risk of prostate cancer or severe lower urinary tract symptoms without prior urological evaluation, recent major adverse cardiovascular event, uncontrolled heart failure or severe untreated sleep apnea. Testosterone replacement therapy should be accompanied by a standardized monitoring plan.

CONCLUSION

The shared decision to treat should be guided by consideration of the burden of symptoms, potential benefits and risks, patient's values, and the cost and burden of long-term treatment and monitoring.

Two females presenting primary amenorrhea diagnosed with Kallmann syndrome caused by novel FGFR1 variants

Primary amenorrhea as the common symptom has a complicated etiology, and genetic disorders are non-negligible. Kallmann syndrome (KS) is a rare inherited disease characterized by hypogonadotropic hypogonadism and anosmia. KS is uncommon in women and is an unusual cause of primary amenorrhea. Herein, we described the clinical features in two female patients presenting primary amenorrhea without puberty. Magnetic resonance imaging showed dysplastic or absent olfactory bulbs and tracts. Eventually, they were diagnosed with KS caused by FGFR1 novel variants, c.315_317delCCCinsTT and c.1081G>A, using whole-exome sequencing (WES). We emphasize that KS should be considered in females presenting primary amenorrhea and anosmia, and recommend that WES should be a priority in the patients presenting primary amenorrhea without secondary sex characteristics.

Slipped Capital Femoral Epiphysis in an Adult with Panhypopituitarism: A Case Report

CASE

Our patient was a 31-year-old woman with previously undiagnosed panhypopituitarism who presented with bilateral slipped capital femoral epiphysis (SCFE). Together with endocrinology, her treatment plan involved medical management of her panhypopituitarism and surgical correction with femoral neck osteotomy. Hormone deficiencies were corrected 6 weeks after replacement therapy began, and the patient was cleared for surgery. By 5 months after osteotomy, examination revealed delayed union and prominent screws bilaterally. Hardware exchange and repeat internal fixation were then performed. At 8 weeks after revision, she presented with avascular necrosis, and the decision was made to proceed with total hip arthroplasty. A 5-year follow-up period was documented.

CONCLUSION

This case presented a rare look at SCFE in an adult patient with panhypopituitarism. Other systemic illnesses that can contribute to SCFE or other orthopaedic issues include, but are not limited to, multiple endocrine neoplasia syndromes, vitamin D deficiency, renal osteodystrophy, Kallmann syndrome, Klinefelter syndrome, and pathologies affecting the thyroid and pituitary gland.

Mechanisms of Central Hypogonadism

Reproductive function depends upon an operational hypothalamo–pituitary–gonadal (HPG) axis. Due to its role in determining survival versus reproductive strategies, the HPG axis is vulnerable to a diverse plethora of signals that ultimately manifest with Central Hypogonadism (CH) in all its many guises. Acquired CH can result from any pituitary or hypothalamic lesion, including its treatment (such as surgical resection and/or radiotherapy). The HPG axis is particularly sensitive to the suppressive effects of hyperprolactinaemia that can occur for many reasons, including prolactinomas, and as a side effect of certain drug therapies. Physiologically, prolactin (combined with the suppressive effects of autonomic neural signals from suckling) plays a key role in suppressing the gonadal axis and establishing temporary CH during lactation. Leptin is a further key endocrine regulator of the HPG axis. During starvation, hypoleptinaemia (from diminished fat stores) results in activation of hypothalamic agouti-related peptide neurons that have a dual purpose to enhance appetite (important for survival) and concomitantly suppresses GnRH neurons via effects on neural kisspeptin release. Obesity is associated with hyperleptinaemia and leptin resistance that may also suppress the HPG axis. The suppressibility of the HPG axis also leaves it vulnerable to the effects of external signals that include morphine, anabolic-androgenic steroids, physical trauma and stress, all of which are relatively common causes of CH. Finally, the HPG axis is susceptible to congenital malformations, with reports of mutations within >50 genes that manifest with congenital CH, including Kallmann Syndrome associated with hyposmia or anosmia (reduction or loss of the sense of smell due to the closely associated migration of GnRH with olfactory neurons during embryogenesis). Analogous to the HPG axis itself, patients with CH are often vulnerable, and their clinical management requires both sensitivity and empathy.

Advances in Genetic Diagnosis of Kallmann Syndrome and Genetic Interruption

Kallmann syndrome (KS) is a rare hereditary disease with high phenotypic and genetic heterogeneity. Congenital hypogonadotropic hypogonadism and hyposmia/anosmia are the two major characterized phenotypes of KS. Besides, mirror movements, dental agenesis, digital bone abnormalities, unilateral renal agenesis, midline facial defects, hearing loss, and eye movement abnormalities can also be observed in KS patients. Because of the phenotypic heterogeneity, genetic diagnosis become increasingly valuable to distinguish KS from other disorders including normosmic congenital hypogonadotropic hypogonadism, constitutional delay of growth and puberty, CHARGE syndrome, and functional hypogonadotropic hypogonadism. Application of next-generation sequencing has promoted the discovery of novel pathogenic genes in KS pedigrees. Prenatal diagnosis is an effective method in clinical settings to decrease birth defects and block transmission of genetic disorders. However, pregnant women may suffer from physical and psychological distress when fetuses are diagnosed with congenital defects. Preimplantation genetic testing (PGT) is a prospective approach during the in vitro fertilization process that helps to interrupt transmission of hereditary diseases to offspring at an early stage. Thus, genetic testing and counseling are recommended to KS patients with family histories, prenatal diagnosis and PGT are considered to be useful options.