Kallmann Syndrome Research Articles

A novel heterozygous variant in exon 32 of the CHD7 gene (c.6923C>T) in a Syrian family with Kallmann syndrome

A novel heterozygous variant in exon 32 of the CHD7 gene (c.6923C>T) in a Syrian family with Kallmann syndrome

Novel Microdeletion in the X Chromosome Leads to Kallmann Syndrome, Ichthyosis, Obesity, and Strabismus.

BackgroundA large deletion in Xp22.3 can result in contiguous gene syndromes, including X-linked ichthyosis (XLI) and Kallmann syndrome (KS), presenting with short stature, chondrodysplasia punctata, intellectual disability, and strabismus. XLI and KS are caused by the deletion of STS and ANOS1, respectively.MethodTwo KS patients with XLI were screened to identify possible pathogenic mutations using whole exome sequencing. The clinical characteristics, molecular genetics, treatment outcomes, and genotype–phenotype association for each patient were analyzed.ResultsWe identified a novel 3,923 kb deletion within the Xp22.31 region (chrX: 5810838–9733877) containing STS, ANOS1, GPR143, NLGN4X, VCX-A, PUDP, and PNPLA4 in patient 1, who presented with KS, XLI, obesity, hyperlipidemia, and strabismus. We identified a novel 5,807 kb deletion within the Xp22.31-p22.33 regions (chrX: 2700083–8507807) containing STS, ANOS1, and other 24 genes in patient 2, who presented with KS, XLI, obesity, and strabismus. No developmental delay, abnormal speech development, or autistic behavior were noticed in either patient.ConclusionWe identified two novel microdeletions in the X chromosome leading to KS and XLI. These findings contribute to the understanding of the molecular mechanisms that drive contiguous gene syndromes. Our research confirmed that the Kallmann-Ichthyosis phenotype is caused by microdeletions at the chromosome level.

CHD7 missense variants and clinical characteristics of Chinese males with infertility.

BackgroundIsolated hypogonadotropic hypogonadism (IHH) and Kallmann syndrome (KS) are rare genetic diseases that cause male infertility. The chromodomain helicase DNA‐binding protein 7 (CHD7) gene is commonly associated with KS and IHH. We speculated that CHD7 variants may be associated with male infertility.MethodsTwo hundred males with azoospermia and 120 with oligozoospermia were recruited. The patients underwent clinical examination and reproductive hormone testing. A panel of genes including CHD7 and others related to spermatogenic failure was sequenced by targeted‐gene exome sequencing.ResultsThree patients with severe oligozoospermia had CHD7 variants (a detection rate of 0.94% (3/320)). After prediction software analysis, two of the variants c.3464G>A (p.R1155H) and c.4516G>A (p.G1506S) were predicted to be likely pathogenic. Although predicted to be benign, the variants of c.2824A>G (p.T942A) located in the chromodomain 2 could not be excluded as disease causing. The patients with variants had small testicular volumes. In particular, the testes of the patient with a p.G1506S variant varied in size (left, 8 ml; right, 4.5 ml). Two patients (patients 31 and 120) had low E2 levels and two (patients 83 and 120) had low T levels. Ultimately, these variants were classified as “variants of unknown significant” that may be associated with male infertility.ConclusionsThere may be a relationship between the CHD7 gene missense variants and male infertility. These variants are easier to find in patients with azoospermia and severe oligospermia whose testosterone levels are decreased.

Functional Characteristics of Novel FGFR1 Mutations in Patients with Isolated Gonadotropin-Releasing Hormone Deficiency.

Isolated gonadotropin-releasing hormone (GnRH) deficiency (IGD) has a wide phenotypic spectrum including Kallmann syndrome (KS) and normosmic idiopathic hypogonadotropic hypogonadism (nIHH). FGFR1 mutations have been identified in 3-10% of patients with KS or nIHH. This study was performed to investigate clinical phenotypes and functional characteristics of FGFR1 mutations in patients with IGD. This study included 8 patients (from 7 families) with FGFR1 mutations identified by targeted gene panel sequencing or whole exome sequencing (WES). The impact of the identified mutations on FGFR1 function was assessed using in vitro studies. Seven heterozygous mutations in FGFR1 were identified in 8 patients from 7 independent families. The patients exhibited a wide spectrum of pubertal development, including anosmia in a prepubertal boy (n=1), delayed puberty (n=2), nIHH (n=3), and KS (n=2). Four of the mutations were classified as likely pathogenic, and the other three were variants of uncertain significance. FGF8-FGFR1 signaling activities for the novel FGFR1 variants (p.Y339H, p.S681I, and p.N185Kfs*16) were reduced by in vitro functional assay, indicating loss-of-function mutations. This study identified seven rare sequence variants in FGFR1 in patients with KS and nIHH. Probands with an FGFR1 mutations displayed a wide phenotypic spectrum ranging from KS to anosmia. A prepubertal male with anosmia should be followed up to assess pubertal development because they can manifest hypogonadotropic hypogonadism after puberty. These results expand the phenotypic spectrum of FGFR1 mutations and suggest a broader biologic role of FGFR1 in reproduction.

Reply to Jakovac: About COVID-19 and vitamin D

Reply to Jakovac: About COVID-19 and vitamin D

Epigenomic control of gonadotrophin-releasing hormone neurone development and hypogonadotrophic hypogonadism.

Mammalian reproductive success depends on gonadotrophin-releasing hormone (GnRH) neurones to stimulate gonadotrophin secretion from the anterior pituitary and activate gonadal steroidogenesis and gametogenesis. Genetic screening studies in patients diagnosed with Kallmann syndrome (KS), a congenital form of hypogonadotrophic hypogonadism (CHH), identified several causal mutations, including those in the fibroblast growth factor (FGF) system. This signalling pathway regulates neuroendocrine progenitor cell proliferation, fate specification and cell survival. Indeed, the GnRH neurone system was absent or abrogated in transgenic mice with reduced (ie, hypomorphic) Fgf8 and/or Fgf receptor (Fgfr) 1 expression, respectively. Moreover, we found that GnRH neurones were absent in the embryonic olfactory placode of Fgf8 hypomorphic mice, the putative birthplace of GnRH neurones. These observations, together with those made in human KS/CHH patients, indicate that the FGF8/FGFR1 signalling system is a requirement for the ontogenesis of the GnRH neuronal system and function. In this review, we discuss how epigenetic factors control the expression of genes such as Fgf8 that are known to be critical for GnRH neurone ontogenesis, fate specification, and the pathogenesis of KS/CHH.

Identification of two novel mutations in three Chinese families with Kallmann syndrome using whole exome sequencing.

Kallmann syndrome (KS) is a rare developmental disorder that manifests as congenital hypogonadotropic hypogonadism with anosmia. More than 19 genes have been found to be associated with KS. However, approximately 70% of the causes of KS remain unclear. Here, we studied seven KS patients, from three families, who had delayed puberty and olfactory bulb dysplasia. However, the families of these patients showed a range of other unique clinical features, including hearing loss, anosmia (to varying degrees) and unilateral renal agenesis. We performed whole exome sequencing and copy number variation (CNV) sequencing on samples acquired from these patients. We identified two novel mutations (c.844delC in ANOS1, c.475C>T in SOX10) and a novel trigenic pattern, PROKR2/CHD7/FEZF1 (c.337T>C in PROKR2, c.748C>G in FEZF1, c.8773G>A in CHD7). The c.844delC mutation in the ANOS1 gene was predicted to generate a truncated form of the anosmin-1 protein. SIFT and PolyPhen-2 predicted that the c.475C>T mutation in SOX10 had a damaging effect. The PROKR2 mutation (c.337T>C) was previously reported as harmful. No pathogenic copy number alterations were detected. Our study expands the genotypic and phenotypic spectrum of KS, a disease that shows considerable clinical and genetic heterogeneity. The application of whole exome sequencing could facilitate our understanding of the pathogenesis of KS.

Prevalence and associated phenotypes of DUSP6, IL17RD and SPRY4 variants in a large Chinese cohort with isolated hypogonadotropic hypogonadism

BackgroundFGF8-FGFR1 signalling is involved in multiple biological processes, while impairment of this signalling is one of the main reasons for isolated hypogonadotropic hypogonadism (IHH). Recently, several negative modulators of FGF8-FGFR1...

SUN-032 Digenic Inheritance of PCSK1 and CHD7 Mutations in PAX4 Homozygous Diabetic Male with Normosmic Hypogonadotropic Hypogonadism

Background: Normosmic congenital hypogonadotropic hypogonadism denotes Kallmann syndrome not associated with anosmia or hyposmia. Over the past few years, the availability of next-generation sequencing has started to unravel the complex molecular basis of congenital hypogonadotrophic hypogonadism including digenic or oligogenic pathogenecity in addition to classic monogenic causality (1). Clinical Case: A 22-year-old male patient was referred to the endocrine clinic in 2018 with recent -onset hyperglycemia. His weight was 82.2 kg with a height of 180 cm (BMI of 25.3 kg/m2). Physical examination revealed small testes, micropenis, and no axillary and pubic terminal hair. His smell sense was intact. His hormonal test reveals low testosterone (0.10 ng/mL) and low free testosterone (0.65 pg/mL) levels with inappropriately low gonadotrophins levels. Secretion of LH and FSH increased 2-fold after GnRH stimulation. His bone age was 13-years 6-months old, and brain magnetic resonance imaging showed the presence of olfactory bulbs, and unremarkable findings except for small size of the pituitary gland. There were no signs associated with CHARGE syndrome (coloboma ocular, heart defects, atresia or stenosis of the choanae, retardation of growth and/or development, genitourinary anomalies, and ear abnormalities). Biochemical investigation demonstrated high serum glucose level and high HbA1c (13.8%). To identify variants to cause the phenotype of the proband, we adopted trio-based whole exome sequencing (WES) and candidate gene approach. Candidate genes was listed from the orphanet (https://www.orpha.net). WES of the proband revealed the presence of heterozygote missense mutations of the CHD7 gene (c.6107C>T, p.Pro2036Leu, rs369543203) and PCSK1 gene (c.239G>A, p.Arg80Gln, rs1799904). The missense variants were predicted to have a damaging effect on the encoded protein, by SIFT and PolyPhen-2 analyses. Genetic analyses of his family revealed that his father had the same heterozygote missense mutations of the CHD7 gene, but wild type of PCSK1. Proband’s mother had the same heterozygote missense mutations of PCSK1, but wild type of CHD7. Furthermore, the proband had homozygote missense mutation of PAX4 (c.575G>A, p.Arg192His, rs2233580) known as maturity-onset diabetes of the young (MODY) 9 gene. Both parents have the same but heterozygous mutation of PAX4 p.Arg192His, and pre-diabetic range of hyperglycemia. Conclusion: This is the first case demonstrating digenic inheritance of mutations in PCSK1 and CHD7 as a potential cause of normosmic hypogonadotrophic hypogonadism, interestingly in PAX4 homozygous diabetic male. Reference: (1) Maione L, et al. Genetic counseling for congenital hypogonadotropic hypogonadism and Kallmann syndrome: new challenges in the era of oligogenism and next-generation sequencing. Eur J Endocrinol. 2018;178(3):R55-R80.

OR16-01 The Expression of the Homeodomain Transcription Factor SIX3 within Kisspeptin Neurons Is Necessary for Reproduction in Mice

The homeodomain transcription factor SIX3 is necessary for normal reproductive processes in mice. The loss of a single allele results in haploinsufficient phenotypes that are reflective of individuals with Kallmann Syndrome, such as hypogonadism, reduced GnRH neurons, and anosmia. Six3 heterozygous mice have reproductive impairments including an increased time to first litter, increased estrous cycle lengths in females, and fewer litters in males compared to wildtype controls. Prior studies found that deleting SIX3 specifically from GnRH neurons did not recapitulate the same phenotypes produced from a global knockout of the Six3 allele and imposed no reproductive abnormalities. This suggests that the role of SIX3 in reproduction is due to SIX3 populations outside of GnRH neurons. Using qPCR and RNA-seq, we have verified that Six3 is expressed in arcuate nucleus (ARC) and anteroventral periventricular nucleus (AVPV) populations of kisspeptin neurons and can regulate the kisspeptin promoter in vitro. This led us to hypothesize that SIX3 in kisspeptin neurons is required for Kiss1 regulation and maximal fertility. We selectively deleted Six3 from kisspeptin neurons by crossing a Six3-floxed mouse with a Kiss1-Cre mouse to produce Six3 flox/flox; Kiss1-Cre positive mice (cKO) and Six3 flox/flox, Kiss-Cre negative littermates (controls). In female mice, we found that the loss of SIX3 from kisspeptin neurons disrupted the estrous cycle and reduced fertility. Compared to controls, cKO mice had fewer cycles in a 16-day period (0.38 vs 1.44; p=0.004; n=8-9), and spent a greater percentage of time in diestrus (80.5 vs 61.8; p=0.002; n=8-9) and a smaller percentage of time in estrus (15.6 vs 29.2; p=0.030; n=8-9). The loss of kisspeptin-specific SIX3 also resulted in reduced fecundity, with the cKO female mice having fewer pups within 90 days (15.0 vs 34.4; p=0.048; n=5-6) compared to controls. In addition to its importance in female mice, kisspeptin-specific SIX3 also plays a role in male fertility. We found that male cKO mice had reduced motile sperm (52.2% vs 72.5%; p=0.012; n=7-9) compared to controls. We also assayed levels of Kiss1 mRNA in the male arcuate nucleus and observed decreased Kiss1 levels compared to controls (0.34 vs 1.01; p=0.042; n=3-4). These results support our hypothesis that SIX3 in kisspeptin neurons is necessary for critical reproductive processes in both females and males, including progression through the estrous cycle, fecundity, and sperm motility, potentially through Kiss1 regulation.

SUN-064 Diversity of Endocrine Function in Patients with CHARGE Association

Context: CHARGE association consists of congenital malformation of Coloboma, Heart defect, Atresia choanae, Retarded growth and development, Genital hypoplasia, Ear anomalies and/or deafness. It is often caused by CHD7 gene mutation, which also one of the causative gene for Kallmann syndrome. The endocrine dysfunction in CHARGE association has been reported but not fully understood. Objective: To clarify the mode of growth and frequency of endocrine dysfunction in CHARGE association. Subjective: We investigated the characteristics of growth and puberty, and endocrine function in 23 children (15 males and 8 females, 0~20 years old) with CHARGE association. Results: The birthweight was from -2.74 to +1.14 SDS and the birth length was from -2.86 to +1.10 SDS. 5 children were born small for gestational age. The height below -2SDS in 18 children. GH secretion was evaluated in 11 children with short stature (-9 to -2.3SD) except for one with normal height (-0.3 SD in 6 years old girl); 5 children including one with normal stature were revealed to have GH deficiency. One short girl with GH deficiency previously showed normal GH response to provocation test at 1 year old but has developed to be GH deficient at 7 years old. Gonadotropin-releasing hormone loading tests were performed in 7 males and 3 females. Nine out of 10 children showed hypogonadotropic hypogonadism; one girl showed hypergonadotropic hypogonadism, whose ovaries were undetectable on ultrasound. Human chorionic gonadotrophin (HCG) tests were performed in 6 males with micropenis and/or cryptorchidism. Peak testosterone levels after HCG stimulation were from 0 to 6.99 ng/ml. 4 patients showed peak testosterone levels less than 1 ng/ml. Four boys showed combined gonadotropin deficiency and primary hypogonadism. Conclusions: Our data showed the diversity of endocrine function in children with CHARGE association. GH deficiency can be developed over time. Hypogonadotropic hypogonadism is common, while isolated/combined primary hypogonadism should be taken into consideration in children with CHARGE association.

OR11-05 Clinical Characteristics and Reproductive Hormone Levels in 201 Men With Congenital and 479 Men With Acquired Hypogonadotropic Hypogonadism: A Single-Center Comparative Study

Context. Hypogonadotropic hypogonadism (HH) is a clinical condition defined by subnormal serum testosterone levels with low serum gonadotropins, which leads to infertility and reduced testicular function in men. HH may be prenatal or congenital (CHH) or acquired (AHH), the latter most commonly related to injury at the hypothalamic/pituitary level. Since diverse medical specialists usually deal with these two disorders, a direct comparison of clinical characteristics and reproductive hormone levels in patients with CHH and AHH has never been performed in a large series. Patients and methods. 201 men with CHH (Kallmann syndrome 52%; normosmic CHH 48%) and 479 men with AHH were included. Causes for AHH included pituitary tumors (74.6%), other intracranial tumors (12.7%; craniopharyngioma 9.1%), infiltrative diseases (3.5%), and other causes (9.2%). We excluded patients with idiopathic late-onset or metabolically-related AHH from this analysis. Testicular volume (TV), serum gonadotropins, total and bioavailable testosterone (TT and BT), estradiol (E2) and testicular peptides inhibin B (IB), AMH and INSL3 were measured at a single center in the absence of any hormone replacement. Results. TV was greater in patients with AHH (16.2±6.3 mL) than in those with CHH (3.4±2.7 mL; p<0.0001). Testicular hypotrophy (mean TV<12 mL) was found in 30% of patients with AHH and in 97% of those with CHH (p<0.0001). When adjusted for age and BMI, men with AHH still had a larger mean TV than those with CHH (p<0.0001). Cryptorchidism was more frequent in patients with CHH than in those with AHH (20.4 vs 0.2%, p<0.0001). Micropenis was found exclusively in patients with CHH. TT levels were higher in patients with AHH (1.4±0.9 ng/mL) than in those with CHH (0.4±0.3 mL, p<0.0001). LH, FSH, BT and E2 were higher in patients with AHH than in those with CHH (p<0.0001 for all parameters), as were IB and INSL3 levels (126±87 vs 59±55 pg/mL, and 566±372 vs 60±40 pg/mL, respectively, p<0.001). In contrast, serum AMH and SHBG levels were lower in patients with AHH than in those with CHH (246±234 vs 46±38 pmol/L, and 35±22 vs 26±21 nmol/L, respectively, p<0.0001). Comparing hormone characteristics across different AHH subgroups, patients with craniopharyngioma (n=44) had lower TV (7.7±5.3 mL) and lower TT, BT, E2, IB and INSL3 levels than those with AHH caused by any other etiology (p<0.05 for all parameters). Conclusions. Our data demonstrate distinct profiles of clinical presentation and reproductive hormones between CHH and AHH. Clinical and hormonal impairment is more severe in patients with CHH than in those with AHH. Preservation of the gonadotrope/testicular axis activity during the fetal, neonatal and pubertal periods in patients with AHH likely accounts for these differences. Among AHH etiologies, patients with craniopharyngioma have the most severe impairment, likely as a result of the intrinsic severity of these tumors, the age at onset, and/or the aggressiveness of the available therapeutic procedures.

Whole genome investigation of an atypical autism case identifies a novel ANOS1 mutation with subsequent diagnosis of Kallmann syndrome

We report an actionable secondary finding from whole-genome sequencing (WGS) of a 10-year-old boy with autism. WGS identified non-synonymous variants in several genes, including a nonsense mutation in the ANOS1 gene which is an X-linked cause of Kallmann syndrome. WGS can provide insights into complex genetic disorders such as autism, and actionable incidental findings can offer the potential for therapeutic interventions.

Metabolomic alterations associated with Kallmann syndrome.

BackgroundThis study was conducted to identify potential seminal plasma metabolic markers associated with disease activity in Kallmann syndrome (KS).MethodsWe collected medical records and seminal plasma samples from 17 KS patients and 20 age-matched healthy controls (HC) and performed metabolomics analysis using the UPLC-QTOF-MS method.ResultsPartial least squares discriminant analysis (PLS-DA) showed that the metabolomics profile of KS patients was clearly separated from HC. Statistical analysis of the data indicates that there are differential metabolites between KS patients and HC. The main metabolic pathways focus on linoleic acid (LA) metabolism, Glycerophospholipid metabolism.ConclusionsThe seminal plasma metabolomics profile of KS patients has changed. Glycerophospholipids and LA are promising biomarkers for KS diagnosis.

Functional analysis of SEMA3A variants identified in Chinese patients with isolated hypogonadotropic hypogonadism.

Isolated hypogonadotropic hypogonadism (IHH) is a rare disorder characterized by impaired sexual development and infertility, caused by the deficiency of hypothalamic gonadotropin-releasing hormone neurons. IHH is named Kallmann's syndrome (KS) or normosmic IHH (nIHH) when associated with a defective or normal sense of smell. Variants in SEMA3A have been recently identified in patients with KS. In this study, we screened SEMA3A variants in a cohort of Chinese patients with IHH by whole exome sequencing. Three novel heterozygous SEMA3A variants (R197Q, R617Q and V458I) were identified in two nIHH and one KS patients, respectively. Functional studies indicated that R197Q and R617Q variants were ineffective in activating the phosphorylation of FAK (focal adhesion kinase) in GN11 cells, despite normal production and secretion in HEK293T cells. The V458I SEMA3A had defect in secretion as it was not detected in the conditioned medium from HEK293T cells. Compared with wild type SEMA3A protein, all three SEMA3A mutant proteins were ineffective in inducing the migration of GN11 cells. Our study further showed the contribution of SEMA3A loss-of-function variants to the pathogenesis of IHH.

Kallmann syndrome in a 17-year-old boy

Aim. To describe a rare hereditary disease — Kallmann syndrome — in a 17-year-old boy.Materials and methods. A retrospective analysis of anamnestic information, the course of the disease, laboratory and instrumental data and treatment of a 17-year-old patient with Kallmann syndrome was carried out. The patient underwent treatment in a gastroenterological department of the Children’s Regional Clinical Hospital in Krasnodar in March 2019.Results. Patient K., 17 years old, was admitted to the gastroenterological department of the Children’s Regional Clinical Hospital in March 2019 with complaints of weakness, nausea, “hungry” abdominal pain and decreased appetite. Upon examination, the child revealed duodenal ulcer. However, an in-depth examination found that the boy was lagging behind in physical and sexual development. In this connection, an endocrinological examination was performed, which discovered: a decrease in the concentration of sex hormones relative to the age norm (luteinizing hormone, follicle-stimulating hormone, testosterone), delayed bone age as compared to the passport age, discrepancy between the testicular size and the patient’s age, olfactory bulb hypoplasia according to brain MRI, 1st degree smell disorder, the presence of a mutation in the KAL1 gene. The boy was diagnosed with: Kallmann syndrome, X-linked recessive inheritance. Complications: hypogonadotropic hypogonadism. The chosen treatment included prolonged testosterone esters for parenteral administration of 250 mg once per 3–4 weeks. Following 6 months of therapy, positive signs were observed: an increase in height by 2 cm, an increase in testicular volume by 3 ml, the appearance of single hairs at the base of the penis.Conclusion. Kallmann syndrome is a rare pathology, whose main manifestations include delayed sexual development and hypo- or anosmia. For a timely diagnosis and treatment, it is of great importance to identify symptoms and conduct a comprehensive examination. Timely initiation of hormonal treatment allows puberty to occur in all cases, thus facilitating social and psychological adaptation of such patients.

Congenital Hypogonadotropic Hypogonadism with Anosmia and Gorlin Features Caused by a PTCH1 Mutation Reveals a New Candidate Gene for Kallmann Syndrome

Background: Two loci (CHD7 and SOX10) underlying Kallmann syndrome (KS) were discovered through clinical and genetic analysis of CHARGE and Waardenburg syndromes, conditions that include congenital anosmia caused by olfactory bulb (CA/OBs) defects and congenital hypogonadotropic hypogonadism (CHH). We hypothesized that other candidate genes for KS could be discovered by analyzing rare syndromes presenting with these signs. Study Design, Size, Duration: We first investigated a family with Gorlin-Goltz syndrome (GGS) in which affected members exhibited clinical signs suggesting KS. Participants/Materials, Methods: Proband and family members underwent detailed clinical assessment. The proband received detailed neuroendocrine evaluation. Genetic analyses included sequencing the PTCH1 gene at diagnosis, followed by exome analyses of causative or candidate KS/CHH genes, in order to exclude contribution to the phenotypes of additional mutations. Exome analyses in additional 124 patients with KS/CHH probands with no additional GGS signs. Results: The proband exhibited CA, absent OBs on magnetic resonance imaging, and had CHH with unilateral cryptorchidism, consistent with KS. Pulsatile Gonadotropin-releasing hormone (GnRH) therapy normalized serum gonadotropins and increased testosterone levels, supporting GnRH deficiency. Genetic studies revealed 3 affected family members harbor a novel mutation of PTCH1 (c.838G> T; p.Glu280*). This unreported nonsense deleterious mutation results in either a putative truncated Ptch1 protein or in an absence of translated Ptch1 protein related to nonsense mediated messenger RNA decay. This heterozygous mutation cosegregates in the pedigree with GGS and CA with OBs aplasia/hypoplasia and with CHH in the proband suggesting a genetic linkage and an autosomal dominant mode of inheritance. No pathogenic rare variants in other KS/CHH genes cosegregated with these phenotypes. In additional 124 KS/CHH patients, 3 additional heterozygous, rare missense variants were found and predicted in silico to be damaging: p.Ser1203Arg, p.Arg1192Ser, and p.Ile108Met. Conclusion: This family suggests that the 2 main signs of KS can be included in GGS associated with PTCH1 mutations. Our data combined with mice models suggest that PTCH1 could be a novel candidate gene for KS/CHH and reinforce the role of the Hedgehog signaling pathway in pathophysiology of KS and GnRH neuron migration.

Expanding the mutational spectrum of monogenic hypogonadotropic hypogonadism: novel mutations in ANOS1 and FGFR1 genes

BackgroundCongenital hypogonadotropic hypogonadism (CHH) is a rare disease, triggered by defective GnRH secretion, that is usually diagnosed in late adolescence or early adulthood due to the lack of spontaneous pubertal development. To date more than 30 genes have been associated with CHH pathogenesis with X-linked recessive, autosomal dominant, autosomal recessive and oligogenic modes of inheritance. Defective sense of smell is present in about 50–60% of CHH patients and called Kallmann syndrome (KS), in contrast to patients with normal sense of smell referred to as normosmic CHH.ANOS1 and FGFR1 genes are all well established in the pathogenesis of CHH and have been extensively studied in many reported cohorts. Due to rarity and heterogenicity of the condition the mutational spectrum, even in classical CHH genes, have yet to be fully characterized.MethodsTo address this issue we screened for ANOS1 and FGFR1 variants in a cohort of 47 unrelated CHH subjects using targeted panel sequencing. All potentially pathogenic variants have been validated with Sanger sequencing.ResultsSequencing revealed two ANOS1 and four FGFR1 mutations in six subjects, of which five are novel and one had been previously reported in CHH. Novel variants include a single base pair deletion c.313delT in exon 3 of ANOS1, three missense variants of FGFR1 predicted to result in the single amino acid substitutions c.331C > T (p.R111C), c.1964 T > C (p.L655P) and c.2167G > A (p.E723K) and a 15 bp deletion c.374_388delTGCCCGCAGACTCCG in exon 4 of FGFR1. Based on ACMG–AMP criteria reported variants were assigned to class 5, pathogenic or class 4, likely pathogenic. Protein structural predictions, the rarity of novel variants and amino acid conservation in case of missense substitutions all provide strong evidence that these mutations are highly likely to be deleterious.ConclusionsDespite the fact that ANOS1 and FGFR1 are classical CHH genes and were thoroughly explored in several CHH cohorts we identified new, yet undescribed variants within their sequence. Our results support the genetic complexity of the disorder. The knowledge of the full genetic spectrum of CHH is increasingly important in order to be able to deliver the best personalised medical care to our patients.

Anosmin-1 activates vascular endothelial growth factor receptor and its related signaling pathway for olfactory bulb angiogenesis

Anosmin-1 is a secreted glycoprotein encoded by the ANOS1 gene, and its loss of function causes Kallmann syndrome (KS), which is characterized by anosmia and hypogonadism due to olfactory bulb (OB) dysfunction. However, the physiological function of anosmin-1 remains to be elucidated. In KS, disordered angiogenesis is observed in OB, resulting in its hypoplasia. In this study, we examined the involvement of anosmin-1 in angiogenic processes. Anosmin-1 was detected on the vessel-like structure in OB of chick embryos, and promoted the outgrowth of vascular sprouts as shown by assays of OB tissue culture. Cell migration, proliferation, and tube formation of endothelial cells were induced by treatment with anosmin-1 as well as vascular endothelial growth factor-A (VEGF-A), and further enhanced by treatment with both of them. We newly identified that anosmin-1 activated VEGF receptor-2 (VEGFR2) by binding directly to it, and its downstream signaling molecules, phospholipase Cγ1 (PLCγ1) and protein kinase C (PKC). These results suggest that anosmin-1 plays a key role in the angiogenesis of developing OB through the VEGFR2–PLCγ1–PKC axis by enhancing the VEGF function.

Multifaceted Functions of Prokineticins in Reproductive Cancers and Proposed Associated Therapies

Prokineticin 1 and prokineticin 2 are two secreted proteins that belong to the prokineticin family. The two ligands act via two G protein-coupled receptors, PROKR1 and PROKR2 to induce cell’s proliferation, migration, invasion and permeability. They mostly act on epithelial, endothelial and immune cells. Deregulations in the expression of the ligands and/or the receptors of this family have been associated with both tumor and non-tumor pathologies of the reproductive system. In these pathologies, prokineticins have been reported to be associated with strong angiogenic and inflammatory activities. While their direct involvement in some threatening reproductive non-tumor pathologies such as kallmann syndrome, polycystic ovaries, preeclampsia and fetal growth restriction are well established, their role and their consideration as potential targets in the tumors of the reproductive system are stil debated. This review will address the multifaceted roles of prokineticins and their receptors in reproductive cancers. Especially, the review will address the role of the prokineticin system in two female cancers, the ovarian cancer and the gestational cancer, Choriocarcinoma. The two types of cancer differentially express the prokineticin ligands at their early developmental stages, leading to different overall responses to be adapted when antagonisation of the prokineticin system is proposed. The review will summarize recent advances in the understanding of the prokineticin system’s involvement in the reproductive cancers, discuss its multifaceted roles in relation to prokineticin’s actions and proposes associated therapies.