Isolated Hypogonadotropic Hypogonadism Patients Research Articles

Magnetic resonance imaging does not distinguish Kallmann syndrome from normosmic isolated hypogonadotropic hypogonadism.

Isolated hypogonadotropic hypogonadism (IHH) may be associated with pituitary gland and olfactory system disorders. We aimed to correlate findings of magnetic resonance imaging (MRI) of the pituitary gland and olfactory system in IHH patients with the patients' olfactory phenotype. The present research was a single-center retrospective case-control study. MRI patterns of the pituitary gland and olfactory system were studied in 46 patients, of whom 29 (63%) were classified on the basis of olfactometry as having Kallmann syndrome (KS) (16 patients with anosmia and 13 patients with hyposmia) and 17 (37%) as having normosmic IHH (nIHH). Results were compared with age- and sex-matched healthy controls. Genetic diagnosis was conducted in all IHH patients based on next-generation sequencing. Almost 70% prevalence of pituitary hypoplasia was observed in IHH subjects. Olfactory bulb (OB) abnormalities were identified in 80.4% of all patients, both the KS (82.8%) and the nIHH (76.5%) subjects. Incidence of unilaterally abnormal, hypoplastic olfactory sulcus (OS) was equally frequent in nIHH and KS. Statistically, piriform cortical thickness was significantly lower in all patient groups than in controls. MRI cannot exclusively differentiate between KS and nIHH, as both conditions may present with OB and OS abnormalities. A surprisingly high frequency of olfactory system abnormalities was observed in nIHH patients, while anterior pituitary hypoplasia was prevalent across all IHH patients. Notably, OB abnormalities were more predominant in KS patients than in those with nIHH.

FRI285 Evidence For ZIC1 As A Novel Gene For Isolated Hypogonadotropic Hypogonadism With Phenotypic Pleiotropic Intersection With Cerebellar Malformation

Abstract Disclosure: J. Cassin: None. D.L. Keefe: None. K.E. Sung: None. C.C. Bojo: None. G. Santiago: None. L. Plummer: None. K.B. Salnikov: None. S.B. Seminara: None. R. Balasubramania: None. P.L. Mellon: None. Isolated Hypogonadotropic Hypogonadism (IHH) is a condition marked by absent pubertal development and low sex steroids in the setting of low/normal gonadotropins. Mutations in known IHH genes only explain <50% of the genetic etiology suggesting significant missing heritability in IHH. To explore this missing IHH heritability, we examined whole exome sequencing data from approximately 1400 IHH probands for rare genetic variants in novel genes that are enriched in IHH patients. We identified four IHH probands with rare, novel heterozygous variants in ZIC1 (p.H134Rfs*21, p.Y287X, p.E299K, p.S413Y), a gene encoding C2H2-type zinc finger protein (rare variant enrichment p <0.0001 for both truncating and missense alleles). Prior literature review show that heterozygous deletions affecting the ZIC1 gene have been linked to Dandy Walker malformation [DWM], a cerebellar malformation, while gain-of-function ZIC1 single nucleotide variants have been linked to coronal craniosynostosis (premature cranial suture fusion). Notably, two IHH subjects with novel ZIC1 variants in our cohort exhibited posterior fossa abnormalities (DWM [p.H134Rfs*21] and ventriculomegaly [E299K]) but none had any cranial suture defects. Given the above genetic enrichment, phenotypic overlap between DWM and IHH, and ZIC1’s known high expression in the hypothalamus, we explored whether ZIC1 regulates the expression of hypothalamic releasing factors. We determined that ZIC1 overexpression increases GNRH1 luciferase expression in the immortalized GnRH cell line, GT1-7. We next explored whether the rare ZIC1 variants identified in the four IHH probands would affect this phenotype. We discovered that three of the four ZIC1 variants significantly reduced GNRH1-luciferase expression. Of those, one truncating mutation, p.H134Rfs*21, resulted in lower ZIC1 protein content in the cell and failure to localize to the nucleus, suggesting a hypomorphic mechanism of action. These findings implicate ZIC1 variants as putatively causal for IHH. Further studies will define the precise ZIC1 transcriptional targets that relate to ZIC1’s pleotropic effects on GnRH transcription, neuronal function, cerebellar development, and cranial suture fusion. Presentation: Friday, June 16, 2023

OR34-04 Defective FGFR1 Signaling Disrupts Glucose Regulation In Humans: Evidence From Patients With Isolated Hypogonadotropic Hypogonadism Harboring FGFR1 Mutations

Abstract Disclosure: M. Stamou: None. C.J. Chiu: None. S. Jadhav: None. K. Salnikov: None. L. Plummer: None. S.B. Seminara: None. R. Balasubramanian: None. Introduction: Recent studies have shown that antibody-mediated activation of FGFR1 receptor improves metabolic health in rodents, nonhuman primates, and humans. Hence, disruption of the FGFR1 receptor may lead to glucose dysregulation. FGFR1 mutations contribute to 12% of the genetic background of subjects with isolated hypogonadotropic hypogonadism (IHH), a rare Mendelian disease caused by GnRH deficiency. In this study, we examined glucose effectiveness and insulin sensitivity in IHH subjects with rare FGFR1 variants and hypothesized that these subjects will display defective glucose metabolism compared healthy non-carrier controls. Methods: Nine subjects with IHH (7 males and 2 females) with heterozygous rare FGFR1 variants were enrolled [7 subjects with protein truncating variants: p.Q680*, p.R622*, p.Q52*, p.I347Nfs*61, p.R576Pfs*77, p.Q309*, c.1553-2A>G and 2 subjects with deleterious missense variants: p.G97S & p.Y701C. Thirty healthy controls (17 males and 13 females) with no FGFR1 variants were enrolled from the Mass General Brigham Biobank. Medical history, physical exam, laboratory evaluation, a bone density scan, and an intravenous glucose tolerance test (IVGTT) were performed. The area under the curve (AUC) for glucose, insulin, and C-peptide response to 50% dextrose (0.3g/kg, t=0min) and an insulin bolus (0.03u/kg, t=20 min) were estimated for each subject. The glucose effectiveness (Sg), insulin sensitivity (SI), acute insulin response to glucose (AIR), and the disposition index (DI= AIRG*SI) were calculated using the Minimal Model Analysis. Statistical comparisons were performed with t-test and non-parametric Wilcoxon rank sum test. A linear regression model was used to adjust the t-test outcomes for potential confounders. Results: Despite similar BMIs (28 vs. 26.5, p=0.29), IHH FGFR1 positive subjects demonstrated higher % fat mass compared to controls (38 vs. 31, p=0.02). IHH patients were supplemented with sex-steroids at the time of the study. Male patients demonstrated similar testosterone levels compared to controls (385 vs. 451 ng/dL, p=0.52). IHH FGFR1 positive subjects demonstrated a higher AUC for C-peptide compared to controls (167 vs. 92, p=0.001), that remained significant after adjusting for age, gender, BMI, and % fat mass. Non-parametric test showed higher AUC for glucose, insulin, and C-peptide (p 0.01, 0.01 & 0.005 respectively) as well as lower SI (p=0.01) and higher AIRg (p=0.037) in the IHH FGFR1 positive group compared to non-carrier controls. Discussion: This is the first study to evaluate glucose metabolism in humans with naturally occurring FGFR1 variants. IHH FGFR1 positive subjects showed higher insulin response to glucose and lower insulin sensitivity during an IVGTT test compared to the healthy non-carrier controls. These findings confirm that FGFR1 signaling is a key regulator of insulin secretion and action in humans. Presentation: Sunday, June 18, 2023

The Evaluation of Testes by Shear Wave Elastography in Patients with Isolated Hypogonadotropic Hypogonadism

Aim: The aim of this study was to evaluate testicular stiffness by shear wave elastography (SWE) in patients with isolated hypogonadotropic hypogonadism (IHH) and to compare it with healthy controls.
 
 Methods: In this prospective study, 35 patients with IHH (group 1) and 40 healthy controls (group 2) were evaluated. These two groups were compared in terms of age, testicular volume, and SWE values. In a subsequent analysis, IHH patients were divided into 3 groups: those who were newly diagnosed and did not receive any treatment (group A), those who received testosterone replacement (group B), and those who received human chorionic gonadotrophin alpha (hCG) (group C). Testicular volumes and SWE values were also compared between these subgroups.
 
 Results: Testicular volumes were significantly lower in group 1 than in group 2 (p

Retard pubertaire d’origine nutritionnelle : Analyse d’une série de cas d’un centre univer sitaire de l’Est Algérien.

Introduction. Malnutrition is one of main reasons for growth and puberty delay. Objective. To determine the prevalence of functional hypogonadotropic hypogonadism (FHH) from nutritional origin, and to study its clinical and biological characteristics. Population and methods. This retrospective study was conducted on 32 cases of FHH [secondary to Chronic Diseases + Constitutional Delay of Growth and Puberty (CDGP)], from a series of 125 patients evaluated for delayed puberty (DP) in the Endocrinology Department of the University Hospital Center of Constantine, between 2000 and 2010, and follow-up for at least 5 years. The diagnosis of malnutrition was clinical, according to the American Academy of Nutrition and Dietetics consensus. Each patient received a general check-up and a gonadotropic and thyrotropic hormonal assay. Other etiological explorations were clinically guided. FHH group was compared with isolated hypogonadotropic hypogonadism (IHH) group. Results. FHH constituted 26% of the series [21 boys/11 girls, (p<0.5)] vs 24% of IHH group. Secondary HHF represented 20% of cases in the series against 6% of CDGP. Malnutrition represented 27% of the series, 11% of which were directly responsible for delayed puberty (DP). Protein-energy undernutrition and iron deficiency anemia, due to inadequate intake, accounted for 62% of nutritional causes. There was a break in the growth curve in 97% of FHH vs 26% of IHH patients (p<0.001). FHH tripled the risk for developing growth retardation. Testicular volume of FHH group was 2.82±0.73 mL (2.69±0.4 mL in patients with malnutrition) vs 2.09±0.87 mL for IHH group (p<0.05). Conclusion. Despite therapeutic progress, DP in CD is common, representing a severity indicator, and poor control of CD. Prevention of FHH requires early detection, nutritional supplementation, and good control disease.

A functional spectrum of PROKR2 mutations identified in isolated hypogonadotropic hypogonadism.

Isolated hypogonadotropic hypogonadism (IHH) is a rare disease with hypogonadism and infertility caused by the defects in embryonic migration of hypothalamic gonadotropin-releasing hormone (GnRH) neurons, hypothalamic GnRH secretion or GnRH signal transduction. PROKR2 gene, encoding a G-protein coupled receptor PROKR2, is one of the most frequently mutated genes identified in IHH patients. However, the functional consequences of several PROKR2 mutants remain elusive. In this study, we systematically analyzed the Gαq, Gαs and ERK1/2 signaling of 23 IHH-associated PROKR2 mutations which are yet to be functionally characterized. We demonstrate that blockage of Gαq, instead of MAPK/ERK pathway, inhibited PROK2-induced migration of PROKR2-expressing cells, implying that PROKR2-related IHH results primarily due to Gαq signaling pathway disruption. Combined with previous reports, we categorized a total of 63 IHH-associated PROKR2 mutations into four distinct groups according Gαq pathway functionality: (i) neutral (N, >80% activity); (ii) low pathogenicity (L, 50-80% activity); (iii) medium pathogenicity (M, 20-50% activity) and (iv) high pathogenicity (H, <20% activity). We further compared the cell-based functional results with in silico mutational prediction programs. Our results indicated that while Sorting Intolerant from Tolerant predictions were accurate for transmembrane region mutations, mutations localized in the intracellular and extracellular domains were accurately predicted by the Combined Annotation Dependent Depletion prediction tool. Our results thus provide a functional database that can be used to guide diagnosis and appropriate genetic counseling in IHH patients with PROKR2 mutations.

Analysis of PLXNA1, NRP1, and NRP2 variants in a cohort of patients with isolated hypogonadotropic hypogonadism.

BackgroundIsolated hypogonadotropic hypogonadism (IHH) is a clinical syndrome described by failure of gonadal function secondary to defects on the synthesis, secretion, or action of the gonadotropin‐releasing hormone (GnRH). The secreted glycoprotein SEMA3A binds its receptors NRP1 or NRP2 and PLXNA to participate in axonal projection, dendritic branching, synaptic formation, and neuronal migration. Deficiency in SEMA3A, NRP1, NRP2, and PLXNA1 have been related to abnormal GnRH neuron development in mice and IHH in humans.MethodsThe aim of this study was to examine the genotypic and phenotypic spectra of the NRP1, NRP2, and PLXNA1 genes in a large cohort of IHH probands from China. We screened NRP1, NRP2, and PLXNA1 variants in Chinese IHH patients by whole exome sequencing and pedigree analysis.ResultsWe identified 10 heterozygous missense variants in PLXNA1, five heterozygous missense variants in NRP1, and two heterozygous missense variants in NRP2. NRP1 variants were found only in IHH patients with defective olfaction (i.e., Kallmann syndrome, KS). In addition, 85% (17/20) of patients harbored variants in other IHH‐associated genes.ConclusionOur study greatly enriched the genotypic and phenotypic spectra of PLXNA1, NRP1, and NRP2 in IHH. It may be conducive to the genetic counseling, diagnosis, and treatment of IHH with mutations in the PLXNA1, NRP1, and NRP2 genes. Furthermore, our results indicated that NRP1 were strongly linked to hearing loss.

Reduced Quality of Life and Sexual Satisfaction in Isolated Hypogonadotropic Hypogonadism.

(1) Background: Isolated hypogonadotropic hypogonadism (IHH) is a genetic condition characterized by impaired puberty and fertility. IHH can significantly impact patient health-related quality of life (HRQoL), sexual satisfaction (SS) and mood. (2) Methods: Participants included 132 IHH subjects (89 men and 43 women) and 132 sex- and age-matched controls. HRQoL, depressive symptoms, erectile dysfunction (ED), and SS were assessed in an online survey using the Zung Self-Rating Depression Scale (SDS), 15D instrument of HRQoL (15D), Sexual Satisfaction Questionnaire (SSQ), and 5-item International Index of Erectile Function (IIEF-5). (3) Results: QoL and SS were significantly lower in the IHH group vs. controls. There was a high rate of ED (53.2% vs. 33%, p = 0.008) and depressive symptoms (45.00 ± 17.00 vs. 32.00 ± 12.00, p < 0.001) in patients vs. controls. The age of patients at IHH diagnosis inversely correlated with their overall 15D scores. An alarming non-compliance rate was seen (51.6%). No differences were found between scores of patients receiving hormone replacement therapy (HRT) and untreated subjects in any of the scales. (4) Conclusions: The HRQoL, SS, ED, and depression levels observed in IHH patients, despite HRT, are alarming. Late IHH diagnosis may have a particularly negative impact on HRQoL. More attention should be devoted to HRT adherence and various HRQoL aspects of IHH patients.

Clinical and molecular features of idiopathic hypogonadotropic hypogonadism in Taiwan: A single center experience

Idiopathic (isolated) hypogonadotropic hypogonadism (IHH) is a rare disease that can be classified as Kallmann syndrome (KS) or normosmic IHH (nIHH). This study investigated the phenotype and genotype of IHH in Taiwanese patients. Twenty-six unrelated IHH patients were included in this study and their clinical, hormonal, and radiological findings were analyzed retrospectively. Whole exome sequencing (WES) was performed to identify the etiology. The 26 patients (M:F=19:7) were divided into a KS group (n=11) and a nIHH group (n=15). The diagnosis was earlier in boys than in girls. Fifteen patients were found to have pathogenic/likely pathogenic (P/LP) variants of IHH-associated genes, and the mutation detection rate was 58%. CHD7, FGFR1, and ANOS1 were the most common genetic etiologies identified in this group. Two patients with nIHH were found to have de novo SOX11 mutations and Coffin-Siris syndrome features. After treatment, the height outcomes and secondary sexual characteristics were significantly improved. There were no obvious differences between the genetically resolved (GR), variants of uncertain significance (VUS) and genetically unresolved groups (GUR). Whole exome sequencing is useful in patients with IHH, and we identified the SOX11 gene as a causal factor in this study. We described the clinical, hormonal, and molecular characteristics, and the treatment outcomes, of Taiwanese patients with IHH, which should aid therapeutic planning and further research.

Exploring the Genetic Diversity of Isolated Hypogonadotropic Hypogonadism and Its Phenotypic Spectrum: A Case Series.

Background:Isolated hypogonadotropic hypogonadism (IHH) is a rare disorder being classified as Kallmann syndrome (KS). The present study was conducted to study the genotype and relative proportion of different genetic mutations in IHH and to assess its correlation with phenotype.Methods:Eleven consecutive subjects presenting to the Department of Endocrinology were retrospectively analyzed during May 2017 to December 2018 with IHH. Phenotypic features and hormonal studies were analyzed along with clinical exome by targeted gene sequencing (Next generation sequencing). Thirty-nine relevant genes were tested in the analysis.Results:Of the 11 patients studied, five had KS and six had nIHH. At diagnosis, mean chronological age was 25 years. There were associated anomalies in KS group including bimanual synkinesia (n=2), unilateral renal agenesis (n=1) and submucosal cleft palate (n=1). Absence or hypoplasia of the olfactory bulb/sulci was found in 4/5 patients with KS. Genetic mutations in KAL1, CHD7, FGFR1, GNRHR, PROKR2, HS6ST1 genes were found in nine of the eleven subjects. Of the five subjects with KS, two had mutations in KAL1 gene. Two siblings who had bimanual synkinesia had CHD7 mutation. The genotype of nIHH subjects (n=6) was more heterogeneous.Conclusion:This study analyzed the clinical, endocrinological, and genetic features in IHH patients. Detectable genetic mutations were seen in a large proportion of cases. A considerable heterogeneity was seen in the genotype with new variants detected. A definite correlation of phenotype-genotype was not possible, and significant overlap was seen between CHD7 and KAl1, and FGFR1 phenotypes.

Evidence for a Common Genetic Origin of Classic and Milder Adult-Onset Forms of Isolated Hypogonadotropic Hypogonadism.

Multiple metabolic and inflammatory mechanisms are considered the determinants of acquired functional isolated hypogonadotropic hypogonadism (IHH) in males, whereas classic IHH is a rare congenital condition with a strong genetic background. Since we recently uncovered a frequent familiarity for classic IHH among patients with mild adult-onset hypogonadism (AO-IHH), here we performed a genetic characterization by next generation sequencing of 160 males with classic or “functional” forms. The prevalence of rare variants in 28 candidate genes was significantly higher than in controls in all IHH patients, independently of the age of IHH onset, degree of hypogonadism or presence of obesity. In fact, it did not differ among patients with classic or milder forms of IHH, however particular genes appear to be more specifically associated with one or the other category of IHH. ROC curves showed that Total Testosterone <6.05 nmol/L and an age of onset <41 years are sensitive cutoffs to identify patients with significantly higher chances of harboring rare IHH gene variants. In conclusion, rare IHH genes variants can frequently predispose to AO-IHH with acquired mild hormonal deficiencies. The identification of a genetic predisposition can improve the familial and individual management of AO-IHH and explain the heritability of congenital IHH.

Testosterone undecanoate supplementation together with human chorionic gonadotropin does not impair spermatogenesis in males with isolated hypogonadotropic hypogonadism: a retrospective study.

Gonadotropin therapy is commonly used to induce virilization and spermatogenesis in male isolated hypogonadotropic hypogonadism (IHH) patients. In clinical practice, 5.6%–15.0% of male IHH patients show poor responses to gonadotropin treatment; therefore, testosterone (T) supplementation can serve as an alternative therapy to normalize serum T levels and promote virilization. However, treatment with exogenous T impairs spermatogenesis and suppresses intratesticular T levels. This retrospective study aimed to determine whether oral testosterone undecanoate (TU) supplementation together with human chorionic gonadotropin (hCG) would negatively affect spermatogenesis in IHH patients compared with hCG alone. One hundred and seven IHH patients were included in our study. Fifty-four patients received intramuscular hCG and oral TU, and 53 patients received intramuscular hCG alone. The median follow-up time was 29 (range: 12–72) months in both groups. Compared with the hCG group, the hCG/TU group required a shorter median time to normalize serum T levels (P < 0.001) and achieve Tanner stage (III and V) of pubic hair and genital development (P < 0.05). However, there were no significant differences in the rate of seminal spermatozoa appearance, sperm concentration, or median time to achieve different sperm concentration thresholds between the groups. In addition, there were no significant differences in side effects, such as acne and gynecomastia, observed in both groups. This study indicates that oral TU supplementation together with hCG does not impair spermatogenesis in treated IHH patients compared with hCG alone, and it shortens the time to normalize serum T levels and promote virilization.

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

To investigate the mutation profiles and clinical characteristics of Chinese males with isolated hypogonadotropic hypogonadism (IHH) and discover new pathogenic genes that cause IHH. A gene panel, including 31 known IHH genes and 52 candidate genes, was used to perform semiconductor next-generation sequencing. University hospital. One hundred thirty-eight sporadic male IHH patients and 10 IHH families; 100 healthy men with normal fertility served as control subjects. None. Targeted next-generation sequencing, polymerase chain reaction and sequencing, pedigree analysis, and bioinformatics analysis. Variants were distributed uniformly throughout 52 genes (52/83, 62.65%), including 16 (16/31, 51.61%) causal genes and 36 (36/52, 69.23%) candidate genes. Six new pathogenic variants and 52 likely pathogenic variants were identified in 16 genes known to cause nIHH/KS (normosmic IHH/Kallmann syndrome). In the 148 probands, PROKR2 (22/148, 14.86%), CHD7, FGFR1, and KAL1 had high mutation rates, and 8.78% (13/148) of the patients carried at least two variants in known genes. In addition, variants were identified in 36 candidate genes, and EGFR, ERBB4, PAX6, IGF1, SEMA4D, and SEMA7A should be prioritized for further research and genetic testing in IHH. The mutation frequency of IHH-causal genes in Chinese HAN males was different from the data reported in white populations. Oligogenic inheritance was a common phenomenon in IHH. Our study expands the mutation profile for IHH, and the new likely pathogenic genes identified in our study warrant further research in GnRH neuronal networks.

Characteristics of a nationwide cohort of patients presenting with isolated hypogonadotropic hypogonadism (IHH).

Isolated hypogonadotropic hypogonadism (IHH) is a rare disorder with pubertal delay, normal (normoosmic-IHH, nIHH) or defective sense of smell (Kallmann syndrome, KS). Other reproductive and non-reproductive anomalies might be present although information on their frequency are scanty, particularly according to the age of presentation. Observational cohort study carried out between January 2008 and June 2016 within a national network of academic or general hospitals. We performed a detailed phenotyping of 503 IHH patients with: (1) manifestations of hypogonadism with low sex steroid hormone and low/normal gonadotropins; (2) absence of expansive hypothalamic/pituitary lesions or multiple pituitary hormone defects. Cohort was divided on IHH onset (PPO, pre-pubertal onset or AO, adult onset) and olfactory function: PPO-nIHH (n = 275), KS (n = 184), AO-nIHH (n = 36) and AO-doIHH (AO-IHH with defective olfaction, n = 8). 90% of patients were classified as PPO and 10% as AO. Typical midline and olfactory defects, bimanual synkinesis and familiarity for pubertal delay were also found among the AO-IHH. Mean age at diagnosis was significantly earlier and more frequently associated with congenital hypogonadism stigmata in patients with Kallmann's syndrome (KS). Synkinesis, renal and male genital tract anomalies were enriched in KS. Overweight/obesity are significantly associated with AO-IHH rather than PPO-IHH. Patients with KS are more prone to develop a severe and complex phenotype than nIHH. The presence of typical extra-gonadal defects and familiarity for PPO-IHH among the AO-IHH patients indicates a common predisposition with variable clinical expression. Overall, these findings improve the understanding of IHH and may have a positive impact on the management of patients and their families.

The effectiveness of zinc supplementation in men with isolated hypogonadotropic hypogonadism.

A multicenter, open-label, randomized, controlled superiority trial with 18 months of follow-up was conducted to investigate whether oral zinc supplementation could further promote spermatogenesis in males with isolated hypogonadotropic hypogonadism (IHH) receiving sequential purified urinary follicular-stimulating hormone/human chorionic gonadotropin (uFSH/hCG) replacement. Sixty-seven Chinese male IHH patients were recruited from the Departments of Endocrinology in eight tertiary hospitals and randomly allocated into the sequential uFSH/hCG group (Group A, n = 34) or the sequential uFSH plus zinc supplementation group (Group B, n = 33). In Group A, patients received sequential uFSH (75 U, three times a week every other 3 months) and hCG (2000 U, twice a week) treatments. In Group B, patients received oral zinc supplementation (40 mg day−1) in addition to the sequential uFSH/hCG treatment given to patients in Group A. The primary outcome was the proportion of patients with a sperm concentration ≥1.0 × 106 ml−1 during the 18 months. The comparison of efficacy between Groups A and B was analyzed. Nineteen of 34 (55.9%) patients receiving sequential uFSH/hCG and 20 of 33 (60.6%) patients receiving sequential uFSH/hCG plus zinc supplementation achieved sperm concentrations ≥1.0 × 106 ml−1 by intention to treat analyses. No differences between Group A and Group B were observed as far as the efficacy of inducing spermatogenesis (P = 0.69). We concluded that the sequential uFSH/hCG plus zinc supplementation regimen had a similar efficacy to the sequential uFSH/hCG treatment alone. The additional improvement of 40 mg day−1 oral zinc supplementation on spermatogenesis and masculinization in male IHH patients is very subtle.

Novel FGFR1 and KISS1R Mutations in Chinese Kallmann Syndrome Males with Cleft Lip/Palate.

Kallmann syndrome (KS) is characterized by isolated hypogonadotropic hypogonadism (IHH) with anosmia and is sometimes associated with cleft lip/palate (CLP). In order to describe the clinical features, genetic etiology, and treatment outcome of KS males with CLP, we performed genetic screening for 15 known causal IHH genes (KAL1, FGFR1, NELF, FGF8, CHD7, WDR11, SEMA3A, KISS1R, KISS1, PROKR2, PROK2, TAC3, TACR3, GNRH1, and GNRHR) in four KS with CLP patients and six IHH patients without CLP. Two novel heterozygous missense mutations in FGFR1, (NM_001174066): c.776G>A (p.G259E) and (NM_001174066): c.358C>T (p.R120C), were identified in a 23-year-old KS male with cleft lip and an 18-year-old KS patient with cleft lip and palate, dental agenesis, and high arched palate, respectively. These two mutations were not presented in their healthy parents and 200 normal controls. One novel heterozygous missense mutation in KISS1R, (NM_032551): c.587C>A (p.P196H), was identified in an 18-year-old KS male with cleft lip and dental agenesis who developed sperm after being treated with gonadotropin. This mutation was also presented in his healthy father and grandfather. These results have implications for the diagnosis, genetic counseling, and treatment of KS and CLP males with mutations in FGFR1 gene.

Role of gonadotropin-releasing hormone receptor mutations in patients with a wide spectrum of pubertal delay

To analyze the GNRHR in patients with normosmic isolated hypogonadotropic hypogonadism (IHH) and constitutional delay of growth and puberty (CDGP). Molecular analysis and invitro experiments correlated with phenotype. Academic medical center. A total of 110 individuals with normosmic IHH (74 male patients) and 50 with CDGP. GNRHR coding region was amplified and sequenced. Novel variants were submitted to invitro analysis. Frequency of mutations and genotype-phenotype correlation were analyzed. Microsatellite markers flanking GNRHR were examined in patients carrying the same mutation to investigate a possible founder effect. Eleven IHH patients (10%) carried biallelic GNRHR mutations. Invitro analysis of novel variants (p.Y283H and p.V134G) demonstrated complete inactivation. The founder effect study revealed that Brazilian patients carrying the p.R139H mutation shared the same haplotype. Phenotypic spectrum in patients with GNRHR mutations varied from complete GnRH deficiency to partial and reversible IHH, with a relatively good genotype-phenotype correlation. One boy with CDGP was heterozygous for the p.Q106R variant, which was not considered to be pathogenic. GNRHR mutations are a frequent cause of congenital normosmic IHH and should be the first candidate gene for genetic screening in this condition, especially in autosomal recessive familial cases. The founder effect study suggested that the p.R139H mutation arises from a common ancestor in the Brazilian population. Finally, mutations in GNRHR do not appear to be involved in the pathogenesis of CDGP.

Nonsense Mutations in FGF8 Gene Causing Different Degrees of Human Gonadotropin-Releasing Deficiency

FGFR1 mutations cause isolated hypogonadotropic hypogonadism (IHH) with or without olfactory abnormalities, Kallmann syndrome, and normosmic IHH respectively. Recently, missense mutations in FGF8, a key ligand for fibroblast growth factor (FGF) receptor 1 in the ontogenesis of GnRH, were identified in IHH patients, thus establishing FGF8 as a novel locus for human GnRH deficiency. Our objective was to analyze the clinical, hormonal, and molecular findings of two familial IHH patients due to FGF8 gene mutations. The entire coding region of the FGF8 gene was amplified and sequenced in two well-phenotyped IHH probands and their relatives. Two unique heterozygous nonsense mutations in FGF8 (p.R127X and p.R129X) were identified in two unrelated IHH probands, which were absent in 150 control individuals. These two mutations, mapped to the core domain of FGF8, impact all four human FGF8 isoforms, and lead to the deletion of a large portion of the protein, generating nonfunctional FGF8 ligands. The p.R127X mutation was identified in an 18-yr-old Kallmann syndrome female. Her four affected siblings with normosmic IHH or delayed puberty also carried the p.R127X mutation. Additional developmental anomalies, including cleft lip and palate and neurosensorial deafness, were also present in this family. The p.R129X mutation was identified in a 30-yr-old man with familial normosmic IHH and severe GnRH deficiency. We identified the first nonsense mutations in the FGF8 gene in familial IHH with variable degrees of GnRH deficiency and olfactory phenotypes, confirming that loss-of-function mutations in FGF8 cause human GnRH deficiency.

Nonsense Mutations inFGF8Gene Causing Different Degrees of Human Gonadotropin-Releasing Deficiency

FGFR1 mutations cause isolated hypogonadotropic hypogonadism (IHH) with or without olfactory abnormalities, Kallmann syndrome, and normosmic IHH respectively. Recently, missense mutations in FGF8, a key ligand for fibroblast growth factor receptor (FGFR) 1 in the ontogenesis of GnRH, were identified in IHH patients, thus establishing FGF8 as a novel locus for human GnRH deficiency. Our objective was to analyze the clinical, hormonal, and molecular findings of two familial IHH patients due to FGF8 gene mutations. The entire coding region of the FGF8 gene was amplified and sequenced in two well-phenotyped IHH probands and their relatives. Two unique heterozygous nonsense mutations in FGF8 (p.R127X and p.R129X) were identified in two unrelated IHH probands, which were absent in 150 control individuals. These two mutations, mapped to the core domain of FGF8, impact all four human FGF8 isoforms, and lead to the deletion of a large portion of the protein, generating nonfunctional FGF8 ligands. The p.R127X mutation was identified in an 18-yr-old Kallmann syndrome female. Her four affected siblings with normosmic IHH or delayed puberty also carried the p.R127X mutation. Additional developmental anomalies, including cleft lip and palate and neurosensorial deafness, were also present in this family. The p.R129X mutation was identified in a 30-yr-old man with familial normosmic IHH and severe GnRH deficiency. We identified the first nonsense mutations in the FGF8 gene in familial IHH with variable degrees of GnRH deficiency and olfactory phenotypes, confirming that loss-of-function mutations in FGF8 cause human GnRH deficiency.

Novel Fibroblast Growth Factor Receptor 1 Mutations in Patients with Congenital Hypogonadotropic Hypogonadism with and without Anosmia

Kallmann syndrome is a clinically and genetically heterogeneous disorder. To date, loss-of-function mutations in the genes encoding anosmin-1 (KAL1) and fibroblast growth factor receptor 1 (FGFR1) have been described in the X-linked and autosomal dominant forms of this syndrome, respectively. The objective was to investigate genetic defects in the KAL1 and FGFR1 genes in patients with congenital isolated hypogonadotropic hypogonadism (IHH). Eighty patients (71 males and nine females) with IHH were studied, of which 30 were familial. Forty-six of them had olfactory abnormalities. The coding regions of both KAL1 and FGFR1 genes were amplified and automatically sequenced. The KAL1 mutations were investigated only in patients with olfactory abnormalities, whereas FGFR1 was studied in the entire group. Two novel KAL1 mutations, an intragenic deletion of exons 3-6 and a splicing mutation IVS7 + 1G>A, were identified in two of 46 patients with Kallmann syndrome. Eight novel heterozygous FGFR1 mutations (G48S, L245P, R250W, A343V, P366L, K618fsX654, P722S, and V795I) were identified in nine of 80 patients with IHH. Eight of them had olfactory abnormalities. Interestingly, the G48S mutation was identified in a normosmic IHH patient. Two unrelated females, who carried FGFR1 mutations, had anosmia and normal reproductive function. We identified novel mutations in KAL1 and FGFR1 genes in IHH patients. FGFR1 mutations were identified in 17% of the patients with olfactory abnormalities and in one of 34 normosmic IHH patients. In addition, isolated anosmia was identified in two unrelated females as a partial phenotypic manifestation of FGFR1 defects.