Iron overload disorders: Growth and gonadal dysfunction in childhood and adolescence.

Hemochromatosis (HC) is characterized by the progressive accumulation of iron in the body, resulting in organ damage. Endocrine complications are particularly common, especially when the condition manifests in childhood or adolescence, when HC can adversely affect linear growth or pubertal development, with significant repercussions on quality of life even into adulthood. Therefore, a timely and accurate diagnosis of these disorders is mandatory, but sometimes complex for hematologists without endocrinological support. This is a narrative review focused on puberty and growth disorders during infancy and adolescence aiming to offer guidance for diagnosis, treatment, and proper follow-up. Additionally, it aims to highlight gaps in the existing literature and emphasizes the importance of collaboration among specialists, which is essential in the era of precision medicine.

Gonadal dysfunction and beyond: Clinical challenges in children, adolescents, and adults with 47,XXY Klinefelter syndrome.

Klinefelter syndrome (KS) is the most frequent sex chromosomal aneuploidy. The karyotype 47,XXY originates from either paternal or maternal meiotic nondisjunction during gametogenesis. KS males are very likely to exhibit marked gonadal dysfunctions, presenting both in severely attenuated spermatogenesis as well as hypergonadotropic hypogonadism. In addition, neurocognitive and psychosocial impairments, as well as cardiovascular, metabolic and bone disorders are often found in KS and might explain for an increased morbidity/mortality. All conditions in KS are likely to be induced by both gene overdosage effects resulting from supernumerary X-chromosomal genes as well as testosterone deficiency. Notwithstanding, the clinical features are highly variable between KS men. Symptoms can become obvious at infancy, childhood, or adolescence. However, the majority of KS subjects is diagnosed during adulthood. KS adolescents require specific attention regarding pubertal development, in order to exploit their remaining fertility potential and allow for timely and tailored testosterone replacement. The chances for sperm retrieval might decline with age and could be hampered by testosterone replacement; therefore, cryostorage of spermatozoa is an option during adolescence, before the decompensation of endocrine and exocrine testicular functions becomes more overt. Sperm from semen or surgically retrieved, in combination with intracytoplasmic sperm injection enables KS males to become biological fathers of healthy children. The aim of this article is to present the current knowledge on KS, to guide clinical care and to highlight research needs.

Effects of treatments on gonadal function in long-term survivors of pediatric hematologic malignancies: A cohort study.

BACKGROUND: Potentially gonadotoxic protocols are currently used for the treatment of childhood hematologic malignancies. This study aims to evaluate the prevalence of gonadal dysfunction and the most important associated risk factors in a cohort of hematologic malignancy survivors. PROCEDURE: We considered all patients referred to our long-term follow-up clinic for childhood cancer survivors, between November 2001 and December 2017. Inclusion criteria were: (a) previous diagnosis of hematologic malignancy; (b) age at hematologic malignancy diagnosis < 18 years; (c) at least five years after the end of anticancer treatments; (d) at least one evaluation of gonadal function after the 18th birthday. Patients diagnosed before January 1, 1990, were excluded. RESULTS: Three hundred twenty-seven survivors (males = 196) were included. Isolated spermatogenesis damage was found in 58/196 (29.6%) of males, whereas 18/196 (9.2%) had Leydig cell failure. In females, 35/131 (26.7%) experienced premature ovarian insufficiency. In both sexes, abdominopelvic irradiation and hematopoietic stem cell transplantation were strongly associated with the risk of gonadal dysfunction. For every 1000 mg/m2 increase in cyclophosphamide-equivalent dose exposure, the risk of spermatogenesis damage increased 1.52-fold and that of Leydig cell failure increased 1.34-fold, whereas the risk of premature ovarian insufficiency increased 1.80-fold. About 30% of those males who developed Leydig cell failure did so more than five years after the end of treatments. CONCLUSIONS: Gonadal dysfunction is still a significant late effect of therapies for pediatric hematologic malignancies. In males, the reevaluation of Leydig cell function may be useful even several years after the exposure to gonadotoxic treatments.

Anti-Müllerian hormone in dogs and cats reproduction.

The anti-Müllerian hormone (AMH) is a glycoprotein secreted by Sertoli cells in males and granulosa cells in females. It has first been determined in blood serum of dogs and cats by Place et al. in 2011 with the use of a human-based ELISA test. Meanwhile, different immunoassays have been validated for AMH determination in animals and a variety of studies have demonstrated the clinical significance of AMH. This review summarizes the current knowledge about AMH in dogs and cats and describes future opportunities for its diagnostic use.

[Analysis of a case with gonadal mosaicism for COL1A2 variant].

OBJECTIVE: To explore the genetic basis for a couple with normal phenotype but repeated pregnancies with fetuses affected by osteogenesis imperfecta. METHODS: Whole exome sequencing (WES) was carried out on fetal specimens and parental DNA to detect potential pathologic variants. Suspected variants were verified by Sanger sequencing. Semen sample of the husband was collected for the extraction of genome DNA, and whole genome amplification (WGA) was performed for single sperms isolated from the sample. RESULTS: WES has identified a heterozygous c.1378G>A (p.G460S) variant of the COL1A2 gene in the fetus, which was predicted to be pathogenic but not detected in peripheral blood samples of both husband and wife. The heterozygotic variant was detected in semen DNA from the husband. Among 15 spermatozoa, 4 were found to harbor the variant. CONCLUSION: The fetus was diagnosed with osteogenesis imperfecta, and the gonadal mosaicism probably accounted for the repeated abnormal pregnancies. Possibility of gonadal mosaicism should be considered when counseling couples with normal phenotype and genotype but recurrent abnormal pregnancies and/or births of children with similar phenotypes and genetic variants.

Effect of the metabolic syndrome on organ damage and mortality in patients with systemic lupus erythematosus: a longitudinal analysis.

OBJECTIVES: To study the effect of the metabolic syndrome (MetS) on organ damage and mortality in patients with SLE. METHODS: Consecutive patients who fulfilled ≥4 ACR criteria for SLE were assessed for the MetS in October 2010. The MetS was defined by the updated joint consensus criteria, using the Asian criteria for central obesity. Longitudinal data on organ damage and mortality were retrieved. The association between MetS and new damage and mortality was studied by logistic regression. RESULTS: A total of 577 SLE patients were followed (93% women; age 41.2±13.4 years; SLE duration 9.3±7.2 years) and 85 (14.7%) patients qualified the MetS. After a follow-up of 66.3±1.8 month, new organ damage and vascular events developed in 128(22%) and 23(4.0%) patients, respectively. Thirty-nine (6.8%) patients succumbed. Patients with the MetS, compared to those without, had significantly more SLICC damage score accrual (0.70±1.0 vs 0.26±0.6; p<0.001), new vascular events (11% vs 2.8%; p=0.001), all-cause (14% vs 5.5%; p=0.003) and vascular (7.1% vs 0.2%; p<0.001) mortality. Logistic regression revealed that the MetS was significantly associated with new damage in the renal (OR 5.48[2.06-14.6]; p=0.001) and endocrine system (OR 38.0[4.50-321]; p=0.001), adjusted for age, sex, SLE duration, ever smoking, antiphospholipid antibodies and the new use of glucocorticoids or hydroxychloroquine since recruitment. Moreover, the presence of the MetS also significantly increased the risk of new vascular events (OR 3.38[1.31-8.74];p=0.01) and vascular mortality (OR 28.3[3.24-247]; p=0.002) after adjustment for the same covariates. CONCLUSION: In this longitudinal study, the MetS is significantly associated with new organ damage, vascular events and mortality in patients with SLE.

Wide spectrum of NR5A1-related phenotypes in 46,XY and 46,XX individuals.

Steroidogenic factor 1 (NR5A1, SF-1, Ad4BP) is a transcriptional regulator of genes involved in adrenal and gonadal development and function. Mutations in NR5A1 have been among the most frequently identified genetic causes of gonadal development disorders and are associated with a wide phenotypic spectrum. In 46,XY individuals, NR5A1-related phenotypes may range from disorders of sex development (DSD) to oligo/azoospermia, and in 46,XX individuals, from 46,XX ovotesticular and testicular DSD to primary ovarian insufficiency (POI). The most common 46,XY phenotype is atypical or female external genitalia with clitoromegaly, palpable gonads, and absence of Müllerian derivatives. Notably, an undervirilized external genitalia is frequently seen at birth, while spontaneous virilization may occur later, at puberty. In 46,XX individuals, NR5A1 mutations are a rare genetic cause of POI, manifesting as primary or secondary amenorrhea, infertility, hypoestrogenism, and elevated gonadotropin levels. Mothers and sisters of 46,XY DSD patients carrying heterozygous NR5A1 mutations may develop POI, and therefore require appropriate counseling. Moreover, the recurrent heterozygous p.Arg92Trp NR5A1 mutation is associated with variable degrees of testis development in 46,XX patients. A clear genotype-phenotype correlation is not seen in patients bearing NR5A1 mutations, suggesting that genetic modifiers, such as pathogenic variants in other testis/ovarian-determining genes, may contribute to the phenotypic expression. Here, we review the published literature on NR5A1-related disease, and discuss our findings at a single tertiary center in Brazil, including ten novel NR5A1 mutations identified in 46,XY DSD patients. The ever-expanding phenotypic range associated with NR5A1 variants in XY and XX individuals confirms its pivotal role in reproductive biology, and should alert clinicians to the possibility of NR5A1 defects in a variety of phenotypes presenting with gonadal dysfunction. Birth Defects Research (Part C) 108:309-320, 2016. © 2016 The Authors Birth Defects Research Part C: Embryo Today: Reviews Published by Wiley Periodicals, Inc.

Why boys will be boys and girls will be girls: Human sex development and its defects.

Among the most defining events of an individual's life, is the development of a human embryo into male or a female. The phenotypic sex of an individual depends on the type of gonad that develops in the embryo, a process which itself is determined by the genetic setting of the individual. The development of the gonads is different from any other organ, as they possess the potential to differentiate into two functionally distinct organs, testes, or ovaries. Sex development can be divided into two distinctive processes, "sex determination," which is the commitment of the undifferentiated gonad into either a testis or an ovary, a process that is genetically programmed in a critically timed manner and "sex differentiation," which takes place through hormones produced by the gonads, once the developmental sex determination decision has been made. Disruption of any of the genes involved in either the testicular or ovarian development pathway could lead to disorders of sex development. In this review, we provide an insight into the factors important for sex determination, their antagonistic actions and whenever possible, references on the "prismatic" clinical cases are given. Birth Defects Research (Part C) 108:365-379, 2016. © 2016 Wiley Periodicals, Inc.

Review disorders of sex development: The evolving role of genomics in diagnosis and gene discovery.

Disorders of Sex Development (DSDs) are a major paediatric concern and are estimated to occur in around 1.7% of all live births (Fausto-Sterling, Sexing the Body: Gender Politics and the Construction of Sexuality, Basic Books, New York, 2000). They are often caused by the breakdown in the complex genetic mechanisms that underlie gonadal development and differentiation. Having a genetic diagnosis can be important for patients with a DSD: it can increase acceptance of a disorder often surrounded by stigma, alter clinical management and it can assist in reproductive planning. While Massively Parallel Sequencing (MPS) is advancing the genetic diagnosis of rare Mendelian disorders, it is not yet clear which MPS assay is best suited for the clinical diagnosis of DSD patients and to what extent other established methods are still relevant. To complicate matters, DSDs represent a wide spectrum of disorders caused by an array of different genetic changes, many of which are yet unknown. Here we discuss the different genetic lesions that are known to contribute to different DSDs, and review the utility of a range of MPS approaches for diagnosing DSD patients. Birth Defects Research (Part C) 108:337-350, 2016. © 2016 Wiley Periodicals, Inc.

Minichromosome maintenance complex component 8 (MCM8) gene mutations result in primary gonadal failure.

BACKGROUND: Primary gonadal failure is characterised by primary amenorrhoea or early menopause in females, and oligospermia or azoospermia in males. Variants of the minichromosome maintenance complex component 8 gene (MCM8) have recently been shown to be significantly associated with women's menopausal age in genome-wide association studies. Furthermore, MCM8-knockout mice are sterile. The objective of this study was to elucidate the genetic aetiology of gonadal failure in two consanguineous families presenting as primary amenorrhoea in the females and as small testes and azoospermia in a male. METHODS AND RESULTS: Using whole exome sequencing, we identified two novel homozygous mutations in the MCM8 gene: a splice (c.1954-1G>A) and a frameshift (c.1469-1470insTA). In each consanguineous family the mutation segregated with the disease and both mutations were absent in 100 ethnically matched controls. The splice mutation led to lack of the wild-type transcript and three different aberrant transcripts predicted to result in either truncated or significantly shorter proteins. Quantitative analysis of the aberrantly spliced transcripts showed a significant decrease in total MCM8 message in affected homozygotes for the mutation, and an intermediate decrease in heterozygous family members. Chromosomal breakage following exposure to mitomcyin C was significantly increased in cells from homozygous individuals for c.1954-1G>A, as well as c.1469-1470insTA. CONCLUSIONS: MCM8, a component of the pre-replication complex, is crucial for gonadal development and maintenance in humans-both males and females. These findings provide new insights into the genetic disorders of infertility and premature menopause in women.

Toward a multi-country monitoring system of reproductive health in the context of endocrine disrupting chemical exposure.

BACKGROUND: Worrying trends regarding human reproductive endpoints (e.g. semen quality, reproductive cancers) have been reported and there is growing circumstantial evidence for a possible causal link between these trends and exposure to endocrine disrupting chemicals (EDCs). However, there is a striking lack of human data to fill the current knowledge gaps. To answer the crucial questions raised on human reproductive health, there is an urgent need for a reproductive surveillance system to be shared across countries. METHODS: A multidisciplinary network named HUman Reproductive health and Global ENvironment Network (HURGENT) was created aiming at designing a European monitoring system for reproductive health indicators. Collaborative work allowed setting up the available knowledge to design such a system. Furthermore we conducted an overview of 23 potential indicators, based upon a weight of evidence (WoE) approach according to their potential relation with EDC exposure. RESULTS: The framework and purposes of the surveillance system are settled as well as the approach to select suitable reproductive indicators. The indicators found with the highest scores according to the WoE approach are prostate and breast cancer incidence, sex ratio, endometriosis and uterine fibroid incidence, indicators related to the testicular dysgenesis syndrome, precocious puberty incidence and reproductive hormone levels. CONCLUSION: Not only sentinel health endpoints, but also diseases with high burdens in public health are highlighted as prior indicators in the context of EDC exposure. Our work can serve as a basis to construct, as soon as possible, the first multi-country reproductive monitoring system.

Menstrual and Gonadal Function Alterations in Women with Systemic Lupus Erythematosus.

PURPOSE: Systemic lupus erythematosus (SLE) is an autoimmune disorder and may affect the reproductive health status of the women. Objective is to analyze the types, incidence of various menstrual disturbances in these women, to identify risk factors and to assess the gonadal function. METHODS: The prospective cohort study was conducted in the SLE clinic of the Rheumatology Department of IPGMEandR, Kolkata from April 2010 to April 2011. Out of 152 females attending clinic, 110 patients fulfilling criteria were included in the study. RESULTS: Mean age of the study population was 27.25±3.4 years. Sixty six cases had menstrual abnormalities (12.72% amenorrhea, 44.45% oligomenorrhea, 2.7% premature ovarian failure, 10.9% menorrhogia). When comparative analysis of demographic, hormonal, ovarian Doppler and therapeutic variables of normal and abnormal cycles was carried out, following parameters were significantly more related to patients with abnormal cycle ; SLEDAI score (12.48±5.53 vs 8.69±4.9; p=0.00), disease duration (6.46±3.08 vs 4.3±1.36; p< 0.05), TSH (7.73±8.64 vs 3.07±2.06; p=0.00.), LH (6.55±4.38 vs 4.56±3.29; p=0.02), a high normal prolactin (12.57±7.75 vs 8.73±3.07; p=0.02), peak systolic velocity (6.53±2.17 vs 9.12±2.1; p=0.00), end-diastolic volume (4.21±2.9 vs 9.35±2.32; p=0.00) and cumulative dose of steroid (24.02±41.44 vs 9.32±9.96; p=0.01).Cyclophosphamide with cumulative dose ≥10 gm was related to amenorrhea and affected gonadal function. Gonadal insufficiency was evident in 33.63% and 2.72% had ovarian failure. CONCLUSIONS: Reduced menstruation is a major health concern in women with SLE as it is frequent and can result in depressed and failed gonadal function later. Doppler study of ovaries is a novel way of depiction of gonadal status in these women. Certain risk factors and revolving treatment part can be preventable.

Increased risk of gonadal malignancy and prophylactic gonadectomy: a study of 102 phenotypic female patients with Y chromosome or Y-derived sequences.

STUDY QUESTION: What is the optimal protocol of management for phenotypic female patients with Y chromosome or Y-derived sequences, in particular for adult patients? SUMMARY ANSWER: Immediate gonadectomy, long-term hormone therapy and psychological care are suggested to be the optimal management for older phenotypic female patients with Y chromosome or Y-derived sequences. WHAT IS KNOWN ALREADY: Phenotypic female patients with Y chromosome or Y-derived sequences are at increasing risk of developing gonadal tumors with age. Early diagnosis and safe guidelines of management for these patients are needed. STUDY DESIGN, SIZE, DURATION: One hundred and two phenotypic women with Y chromosome or Y-derived sequences were included in a straightforward, retrospective-observational study conducted over a period of 26 years from January 1985 to November 2010. PARTICIPANTS/MATERIALS, SETTING AND METHODS: Patients aged 16-34 years presenting to our Academic Department of Gynecology with symptoms of disorders of sex development were subjected to history taking, hormonal evaluation, conventional cytogenetic analysis, PCR, histopathology and immunohistochemistry. Features of the gonads were examined and the outcome of prophylactic gonadectomy evaluated. MAIN RESULTS AND THE ROLE OF CHANCE: Among the patients recruited in our study, 48 patients (47.1%) were diagnosed with complete/partial androgen insensitivity syndrome (CAIS/PAIS) (46XY), 33 cases (32.4%) with gonadal dysgenesis (46XY) and the remaining subjects (20.1%) with mixed gonadal dysgenesis (with sex chromosome structural abnormalities). The total incidence of malignancy was 17.6%. Seventeen patients (16.7%) had gonadoblastoma, while one patient (1.0%) with gonadal dysgenesis had dysgerminoma. Gonadoblastoma were observed in 2/21 patients with sex chromosome structural abnormalities (9.5%), 3/33 patients with gonadal dysgenesis (9.1%), 9/30 patients with CAIS (30.0%) and 3/18 patients with PAIS (16.7%). LIMITATIONS, REASONS FOR CAUTION: Selection bias in this cohort study may affect data interpretation due to the low incidence of disorders of sex development in the general population. WIDER IMPLICATIONS OF THE FINDINGS: The risk for malignant transformation may occur in early life and highly increase with age in patients with Y chromosome or Y-derived sequences. Optimal timing of gonadectomy should be decided by multiple factors including the subgroup of disorder, age and degree of patient's maturity. In addition, gonadal biopsy is suggested when the disease is diagnosed and any evidence of premalignancy warranties gonadectomy. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the National Key Scientific Research Project (2013CB967404), Natural Science Funds of Zhejiang Province (Y13H04005), Zhejiang Qianjiang talent plan (2013R10027), the Fundamental Research Funds for the Central Universities and Key Projects in the National Science & Technology Pillar Program during the Eleventh Five-Year Plan Period (2012BAI32B04). The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER None.

Evaluating the patients with thalassemia major for long-term endocrinological complications after bone marrow transplantation.

The aim of this study was to evaluate the endocrinological complications of the patients with thalassemia major (TM) who underwent bone marrow transplantation (BMT) and followed-up more than two years in our center, prospectively. "BMT group" consisted of 41 patients with TM. The mean age was 12.4 ± 5.4 years and transplantation age was mean 7.5 ± 4.9 years. Post-BMT follow-up lasted from 24 to 122 months (mean 65.07 months). Also, 32 TM patients with similar age group and same history of transfusion and chelation therapy were recruited for the study as "control (C) group". The weight SDS score after transplantation was found better than before transplantation (p = 0.010). There was a negative correlation between height SDS and BMT age (p = 0.008). The height SDS scores were better in patients whose BMT age was under seven years old compared to those older than seven years old (p = 0.02). Z-scores of femur neck and L2-4 vertebrae DEXA were decreased (p = 0.032, p = 0.0001) and incidence of insulin resistance increased (p = 0.01) in patients with increased BMT age. The risk of gonadal insufficiency was significantly lower in the patients who underwent BMT <7 years of age (p = 0.009). There was no statistically significant relationship between BMT age and complications such as hypothyroidism, hypoparathyroidism, and adrenal insufficiency. The patients with TM should be evaluated for transplantation in early stage of the disease, especially before the age of seven years. Because the BMT cannot correct the endocrinological complications of TM completely, the patients should be followed up regularly after the transplantation.

[Androgen receptor polymorphism in relation to medical conditions characterized by hyper/hypoandrogenism].

An androgen receptor (AR) is a transcription factor consisting of four functional regions. The transactivation region contains a highly polymorphic area characterized by a variable number of CAG trinucleotide repeats encoding a polyglutamine tract. Several in vitro studies demonstrated a negative linear relation between the lengths of CAG repeats and relative AR transactivations. Numerous clinical studies then sought associations between the described polymorphism and clinical parameters of various medical conditions characterized by hyper/hypoandrogenism. In this article, we describe some of those interesting associations. We believe such links should be investigated in any medical condition involving androgens as a key element in its pathogenesis.

Gonadal dysfunction in women with diabetes mellitus.

It is well known that both type 1 and type 2 diabetes mellitus (DM) are related to increased risk for cardiovascular (CV) and chronic kidney disease (CKD). However, besides these prominently presented complications, DM has also been associated with reproductive dysfunctions. It seems that these disorders are met in up to 40% of women with DM and consist of delayed menarche, all types of menstrual disorders, such as amenorrhea, oligomenorrhea, menstrual irregularity, as well as menorrhagia, infertility, characteristics of polycystic ovary syndrome (PCOS) and early (or rarely late) menopause. In type 1 DM (T1DM), insulin treatment, although it has reduced the rates of insulinopenic-induced hypogonadotropic hypogonadism, an entity commonly presented in many women with the disease in the past decades, when it is used in excess it can also promote hyperandrogenism. Regarding type 2 DM (T2DM), insulin resistance (IR) and hyperinsulinemia have mainly been implicated in the pathogenesis of reproductive dysfunctions, as insulin can act as gonadotropin on the theca cells of the ovary and can lead to hyperandrogenism and inhibition of proper ovulation. This review aims to detail the reproductive dysfunctions associated with DM and provide scientific data to enlighten the underlying pathogenetic mechanisms.

[Management of endocrine dysfunctions after allogeneic hematopoietic stem cell transplantation: a report of the SFGM-TC on gonadal failure and fertility]. / Suivi et prise en charge des troubles endocriniens en post-greffe de cellules souches hématopoïétiques: insuffisance gonadique et fertilité

In the attempt to harmonize clinical practices between different French transplantation centers, the French Society of Bone Marrow Transplantation and Cell Therapy (SFGM-TC) set up the third annual series of workshops which brought together practitioners from all member centers and took place in October 2012 in Lille. Here we report our results and recommendations regarding the management of short and long-term endocrine dysfunction following allogeneic stem cell transplantation. The key aim of this workshop was to give an overview gonadal failure, fertility preservation and post-transplant.

Causes and risk factors for male-factor infertility in Nigeria: a review.

In recent times there has been a decline in the semen quality of young healthy men worldwide, with similar findings being reported in Nigeria. Although little is known about what is responsible for the decline in male sperm count worldwide, significant associations have been reported between impaired semen quality including sperm count, motility as well as morphology and exposures to heavy metals such as cadmium and lead, mycotoxins such as aflatoxins, pesticides, industrial chemicals and endocrine factors. In Nigeria, the problem is further compounded by a variety of factors such as sexually transmitted infections, genito-urinary tract infections/inflammations and deficiencies of dietary antioxidant nutrients, thereby increasing male-factor contribution to infertility in the population. In this article, we analyze data from different sources and present evidence of the possible etiology and risk factors for male-factor infertility in Nigeria.

Paediatric Wolfram syndrome Type 1: should gonadal dysfunction be part of the diagnostic criteria?

Aims: Wolfram Syndrome Spectrum Disorder (WFS1-SD), in its "classic" form, is a rare autosomal recessive disease with poor prognosis and wide phenotypic spectrum. Insulin dependent diabetes mellitus (DM), optic atrophy (OA) diabetes insipidus (DI) and sensorineural deafness (D) are the main features of WFS1-SD. Gonadal dysfunction (GD) has been described mainly in adults with variable prevalence and referred to as a minor clinical feature. This is the first case series investigating gonadal function in a small cohort of paediatric patients affected by WFS1-SD. Methods: Gonadal function was investigated in eight patients (3 male and 5 female) between 3 and 16 years of age. Seven patients have been diagnosed with classic WFS1-SD and one with non-classic WFS1-SD. Gonadotropin and sex hormone levels were monitored, as well as markers of gonadal reserve (inhibin-B and anti-Mullerian hormone). Pubertal progression was assessed according to Tanner staging. Results: Primary hypogonadism was diagnosed in 50% of patients (n=4), more specifically 67% (n=2) of males and 40% of females (n=2). Pubertal delay was observed in one female patient. These data confirm that gonadal dysfunction may be a frequent and underdiagnosed clinical feature in WFS1-SD. Conclusions: GD may represent a frequent and earlier than previously described feature in WFS1-SD with repercussions on morbidity and quality of life. Consequently, we suggest that GD should be included amongst clinical diagnostic criteria for WFS1-SD, as has already been proposed for urinary dysfunction. Considering the heterogeneous and elusive presentation of WFS1-SD, this clinical feature may assist in an earlier diagnosis and timely follow-up and care of treatable associated diseases (i.e. insulin and sex hormone replacement) in these young patients.