Plasma pentraxin-3 levels and its role in childhood obesity-Is it anti-inflammatory? A matched group study.

OBJECTIVE: Obesity has been associated with chronic low-grade systemic inflammation. This study aimed to investigate the relationship of pentraxin-3 (PTX-3) with anthropometric measurements, dietary content and physical activity level in children. DESIGN: A matched group study. PATIENTS: This study was conducted with 91 children aged 6-17 years, divided into two groups: "non-obese group" (Body Mass Index Standard Deviation Score [BMI SDS] <95th percentile) and "obese group" (BMI SDS ≥95th percentile). MEASUREMENTS: Plasma PTX-3 levels. RESULTS: The mean age of 91 children included in the study was 12.34 ± 2.86 years. Plasma PTX-3 levels were significantly higher in obese children (p = .028). No significant correlation was found between BMI SDS and plasma PTX-3 values, but a weak positive correlation was found when physical activity level was controlled (r = .176, p = .049). In addition, it was found that fat mass was a partial mediator of plasma PTX-3 level, and an increase in the amount of subcutaneous adipose tissue negatively affected plasma PTX-3 level. Plasma PTX-3 level showed a weak positive correlation (r = .223, p = .017) with physical activity score and dietary polyunsaturated fatty acid intake, while a weak negative correlation with neutrophil-to-lymphocyte ratio. One unit increase in physical activity score or polyunsaturated fatty acid level caused 0.730 and 2.061 unit increases in plasma PTX-3 level, respectively; while one unit increase in dietary fat intake caused 0.413-unit decrease. CONCLUSION: There was an indirect relationship between the amount of subcutaneous adipose tissue and PTX-3 level. The results of our study suggested that plasma PTX-3 was associated with lower levels of inflammation in children.

A novel homozygous nonsense NDNF variant in Kallmann syndrome.

Kallmann syndrome (KS) is a rare genetic disease characterized by pubertal failure and olfactory defects. Although many genes associated with KS have been reported, most are rare. Recently, heterozygous inactivating mutations in the neuron-derived neurotrophic factor gene (NDNF) were reported to cause KS. Here, we present a 14-year-old Kurdish boy with KS who has a novel homozygous nonsense c.1251C>A (p.Tyr417Ter) variant in NDNF. The variant was not observed in reference population databases and was predicted to be deleterious. Segregation analysis performed with Sanger sequencing indicated the autosomal recessive inheritance of the clinical phenotype. His heterozygous parents have experienced timely pubertal development and normal reproductive features. This study reported the first homozygous truncating NDNF variant, enabling the direct observation of the clinical consequences of predictively absent NDNF function. These results support the contention that the inactivating mutations in NDNF cause KS, and provide additional evidence for the complex inheritance of KS.

Inactivating NHLH2 variants cause idiopathic hypogonadotropic hypogonadism and obesity in humans.

Metabolism has a role in determining the time of pubertal development and fertility. Nonetheless, molecular/cellular pathways linking metabolism/body weight to puberty/reproduction are unknown. The KNDy (Kisspeptin/Neurokinin B/Dynorphin) neurons in the arcuate nucleus of the hypothalamus constitute the GnRH (gonadotropin-releasing hormone) pulse generator. We previously created a mouse model with a whole-body targeted deletion of nescient helix-loop-helix 2 (Nhlh2; N2KO), a class II member of the basic helix-loop-helix family of transcription factors. As this mouse model features pubertal failure and late-onset obesity, we wanted to study whether NHLH2 represents a candidate molecule to link metabolism and puberty in the hypothalamus. Exome sequencing of a large Idiopathic Hypogonadotropic Hypogonadism cohort revealed obese patients with rare sequence variants in NHLH2, which were characterized by in-silico protein analysis, chromatin immunoprecipitation, and luciferase reporter assays. In vitro heterologous expression studies demonstrated that the variant p.R79C impairs Nhlh2 binding to the Mc4r promoter. Furthermore, p.R79C and other variants show impaired transactivation of the human KISS1 promoter. These are the first inactivating human variants that support NHLH2's critical role in human puberty and body weight control. Failure to carry out this function results in the absence of pubertal development and late-onset obesity in humans.

Loss-of-function variants in SEMA3F and PLXNA3 encoding semaphorin-3F and its receptor plexin-A3 respectively cause idiopathic hypogonadotropic hypogonadism.

PURPOSE: Idiopathic hypogonadotropic hypogonadism (IHH) is characterized by absent puberty and subsequent infertility due to gonadotropin-releasing hormone (GnRH) deficiency. IHH can be accompanied by normal or compromised olfaction (Kallmann syndrome). Several semaphorins are known potent modulators of GnRH, olfactory, and vomeronasal system development. In this study, we investigated the role of Semaphorin-3F signaling in the etiology of IHH. METHODS: We screened 216 IHH patients by exome sequencing. We transiently transfected HEK293T cells with plasmids encoding wild type (WT) or corresponding variants to investigate the functional consequences. We performed fluorescent IHC to assess SEMA3F and PLXNA3 expression both in the nasal region and at the nasal/forebrain junction during the early human fetal development. RESULTS: We identified ten rare missense variants in SEMA3F and PLXNA3 in 15 patients from 11 independent families. Most of these variants were predicted to be deleterious by functional assays. SEMA3F and PLXNA3 are both expressed along the olfactory nerve and intracranial projection of the vomeronasal nerve/terminal nerve. PLXNA1-A3 are expressed in the early migratory GnRH neurons. CONCLUSION: SEMA3F signaling through PLXNA1-A3 is involved in the guidance of GnRH neurons and of olfactory and vomeronasal nerve fibers in humans. Overall, our findings suggest that Semaphorin-3F signaling insufficiency contributes to the pathogenesis of IHH.

Prevalence and associated phenotypes of PLXNA1 variants in normosmic and anosmic idiopathic hypogonadotropic hypogonadism.

Idiopathic hypogonadotropic hypogonadism (IHH) can be divided into two major forms, normosmic IHH and Kallmann syndrome (KS). Genetic mutations are responsible for the majority of IHH. PLXNA1 has recently been implicated in the GnRH neuron migration and the etiology of KS. We aimed to investigate the prevalence and associated phenotypes of PLXNA1 variants in a large cohort of IHH patients. We screened the whole exome data of 215 IHH patients in a single center for causative PLXNA1 variants. Our studies showed eight novel (p.Arg836His, p.Lys1451Arg, p.Val287Met, p.Val536Ile, p.Ser1850Arg, p.Ile1701Val, p.Arg319Trp, and p.Pro485Leu) and two previously described (p.Arg528Trp and p.Gly720Glu) heterozygous PLXNA1 variants in nine affected individuals from seven unrelated families. Only three of nine patients were anosmic (KS) while the remaining patients showed normal olfactory function (nIHH). Seven of nine patients (77.7%) harbored additional one or two variants in other nIHH/KS-associated genes, including PROKR2, IGSF10, HS6ST1, SEMA3E, CCDC141, FGFR1, NRP1, POLR3A, and SRA1. Our findings indicate that PLXNA1 variants cause not only anosmic but also normosmic IHH with a relatively high prevalence (3.9%). Heterozygous missense PLXNA1 variants appear to be involved together with other IHH gene variants in bringing about the IHH disease phenotype.

Molecular genetic studies in a case series of isolated hypoaldosteronism due to biosynthesis defects or aldosterone resistance.

BACKGROUND AND AIM: Hypoaldosteronism is associated with either insufficient aldosterone production or aldosterone resistance (pseudohypoaldosteronism). Patients with aldosterone defects typically present with similar symptoms and findings, which include failure to thrive, vomiting, hyponatremia, hyperkalemia and metabolic acidosis. Accurate diagnosis of these clinical conditions therefore can be challenging. Molecular genetic analyses can help to greatly clarify this complexity. The aim of this study was to obtain an overview of the clinical and genetic characteristics of patients with aldosterone defects due to biosynthesis defects or aldosterone resistance. DESIGN AND PATIENTS: We investigated the clinical and molecular genetic features of 8 consecutive patients with a clinical picture of aldosterone defects seen in our clinics during the period of May 2015 through October 2017. We screened CYP11B2 for aldosterone synthesis defects and NR3C2 and the three EnaC subunits (SCNN1A, SCNN1B and SCNN1G) for aldosterone resistance. RESULTS: We found 4 novel and 2 previously reported mutations in the genes CYP11B2, NR3C2, SCNN1A and SCNN1G in 9 affected individuals from 7 unrelated families. CONCLUSION: Molecular genetic investigations can help confidently diagnose these conditions and clarify the pathogenicity of aldosterone defects. This study may expand the clinical and genetic correlations of defects in aldosterone synthesis or resistance.

Mutations in FEZF1 cause Kallmann syndrome.

Gonadotropin-releasing hormone (GnRH) neurons originate outside the CNS in the olfactory placode and migrate into the CNS, where they become integral components of the hypothalamic-pituitary-gonadal (HPG) axis. Disruption of this migration results in Kallmann syndrome (KS), which is characterized by anosmia and pubertal failure due to hypogonadotropic hypogonadism. Using candidate-gene screening, autozygosity mapping, and whole-exome sequencing in a cohort of 30 individuals with KS, we searched for genes newly associated with KS. We identified homozygous loss-of-function mutations in FEZF1 in two independent consanguineous families each with two affected siblings. The FEZF1 product is known to enable axons of olfactory receptor neurons (ORNs) to penetrate the CNS basal lamina in mice. Because a subset of axons in these tracks is the migratory pathway for GnRH neurons, in FEZF1 deficiency, GnRH neurons also fail to enter the brain. These results indicate that FEZF1 is required for establishment of the central component of the HPG axis in humans.

Anthropometric findings from birth to adulthood and their relation with karyotpye distribution in Turkish girls with Turner syndrome.

To evaluate the anthropometric features of girls with Turner syndrome (TS) at birth and presentation and the effect of karyotype on these parameters. Data were collected from 842 patients with TS from 35 different centers, who were followed-up between 1984 and 2014 and whose diagnosis age ranged from birth to 18 years. Of the 842 patients, 122 girls who received growth hormone, estrogen or oxandrolone were excluded, and 720 girls were included in the study. In this cohort, the frequency of small for gestational age (SGA) birth was 33%. The frequency of SGA birth was 4.2% (2/48) in preterm and 36% (174/483) in term neonates (P < 0.001). The mean birth length was 1.3 cm shorter and mean birth weight was 0.36 kg lower than that of the normal population. The mean age at diagnosis was 10.1 ± 4.4 years. Mean height, weight and body mass index standard deviation scores at presentation were -3.1 ± 1.7, -1.4 ± 1.5, and 0.4 ± 1.7, respectively. Patients with isochromosome Xq were significantly heavier than those with other karyotype groups (P = 0.007). Age at presentation was negatively correlated and mid-parental height was positively correlated with height at presentation. Mid-parental height and age at presentation were the only parameters that were associated with height of children with TS. The frequency of SGA birth was found higher in preterm than term neonates but the mechanism could not be clarified. We found no effect of karyotype on height of girls with TS, whereas weight was greater in 46,X,i(Xq) and 45,X/46,X,i(Xq) karyotype groups.

Inactivating KISS1 mutation and hypogonadotropic hypogonadism.

Gonadotropin-releasing hormone (GnRH) is the central regulator of gonadotropins, which stimulate gonadal function. Hypothalamic neurons that produce kisspeptin and neurokinin B stimulate GnRH release. Inactivating mutations in the genes encoding the human kisspeptin receptor (KISS1R, formerly called GPR54), neurokinin B (TAC3), and the neurokinin B receptor (TACR3) result in pubertal failure. However, human kisspeptin loss-of-function mutations have not been described, and contradictory findings have been reported in Kiss1-knockout mice. We describe an inactivating mutation in KISS1 in a large consanguineous family that results in failure of pubertal progression, indicating that functional kisspeptin is important for puberty and reproduction in humans. (Funded by the Scientific and Technological Research Council of Turkey [TÜBITAK] and others.).

Normosmic idiopathic hypogonadotropic hypogonadism due to a novel homozygous nonsense c.C969A (p.Y323X) mutation in the KISS1R gene in three unrelated families.

OBJECTIVE: The spectrum of genetic alterations in cases of hypogonadotropic hypogonadism continue to expand. However, KISS1R mutations remain rare. The aim of this study was to understand the molecular basis of normosmic idiopathic hypogonadotropic hypogonadism. METHODS: Clinical characteristics, hormonal studies and genetic analyses of seven cases with idiopathic normosmic hypogonadotropic hypogonadism (nIHH) from three unrelated consanguineous families are presented. RESULTS: One male presented with absence of pubertal onset and required surgery for severe penoscrotal hypospadias and cryptorchidism, while other two males had absence of pubertal onset. Two of four female cases required replacement therapy for pubertal onset and maintenance, whereas the other two had spontaneous pubertal onset but incomplete maturation. In sequence analysis, we identified a novel homozygous nonsense (p.Y323X) mutation (c.C969A) in the last exon of the KISS1R gene in all clinically affected cases. CONCLUSIONS: We identified a homozygous nonsense mutation in the KISS1R gene in three unrelated families with nIHH, which enabled us to observe the phenotypic consequences of this rare condition. Escape from nonsense-mediated decay, and thus production of abnormal proteins, may account for the variable severity of the phenotype. Although KISS1R mutations are extremely rare and can cause a heterogeneous phenotype, analysis of the KISS1R gene should be a part of genetic analysis of patients with nIHH, to allow better understanding of phenotype-genotype relationship of KISS1R mutations and the underlying genetic basis of patients with nIHH.

Hashimoto's encephalopathy: four cases and review of literature.

Hashimoto's encephalopathy is a rare clinically heterogenous condition consisting of encephalopathy, seizures and variable neurological and psychiatric manifestations, accompanied by high titres of serum antithyroid antibodies. We described the clinical and laboratory findings of four children (aged 8-17 years) with Hashimoto's encephalopathy. The clinical features of three patients at presentation included refractory epilepsy, and confusion, and one patient presented with behavioral and cognitive changes. During their presentation, two of them were in euthyroid, and the others were in hypothyroid status. All patients manifested increased antithyroid antibodies. Two patients improved with steroid treatment. The others responded to plasmapheresis instead of corticosteroid treatment. Physicians' awareness of this complication is of great importance because most patients respond dramatically to the treatment.

POU6F2 mutation in humans with pubertal failure alters GnRH transcript expression.

Idiopathic hypogonadotropic hypogonadism (IHH) is characterized by the absence of pubertal development and subsequent impaired fertility often due to gonadotropin-releasing hormone (GnRH) deficits. Exome sequencing of two independent cohorts of IHH patients identified 12 rare missense variants in POU6F2 in 15 patients. POU6F2 encodes two distinct isoforms. In the adult mouse, expression of both isoform1 and isoform2 was detected in the brain, pituitary, and gonads. However, only isoform1 was detected in mouse primary GnRH cells and three immortalized GnRH cell lines, two mouse and one human. To date, the function of isoform2 has been verified as a transcription factor, while the function of isoform1 has been unknown. In the present report, bioinformatics and cell assays on a human-derived GnRH cell line reveal a novel function for isoform1, demonstrating it can act as a transcriptional regulator, decreasing GNRH1 expression. In addition, the impact of the two most prevalent POU6F2 variants, identified in five IHH patients, that were located at/or close to the DNA-binding domain was examined. Notably, one of these mutations prevented the repression of GnRH transcripts by isoform1. Normally, GnRH transcription increases as GnRH cells mature as they near migrate into the brain. Augmentation earlier during development can disrupt normal GnRH cell migration, consistent with some POU6F2 variants contributing to the IHH pathogenesis.

Chromium levels in healthy and newly diagnosed type 1 diabetic children.

BACKGROUND: The aim of this study was to compare the chromium levels of plasma (PCL), erythrocyte (ECL) and urine (UCL) in type 1 diabetics and healthy subjects and to review the relation between metabolic parameters. METHODS: We evaluated 165 subjects who were: newly diagnosed type 1 diabetics (group 1 [n= 29]); previously diagnosed type 1 diabetics (group 2 [n= 18]); non-diabetic control subjects who were admitted and treated for any reason in hospital (group 3 [n= 21]); and two other groups of control subjects from two schools that have different socioeconomic levels (group 4 [n= 48] and group 5 [n= 49]). RESULTS: PCL in group 1 and group 2 subjects (7.21 ± 4.78 and 10.94 ± 3.04 mcg/L, respectively) was significantly lower than in all control groups (21.84 ± 7.87, 16.11 ± 7.44, 17.25 ± 8.58 mcg/L, respectively) (P < 0.05). A significant difference in PCL between the group 1 and group 2 subjects was present (7.21 ± 4.78 and 10.94 ± 3.04, respectively) (P= 0.021). ECL (as tissue chromium) in group 1 and group 2 subjects (13.99 ± 11.37 and 19.64 ± 12.58, respectively) was significantly lower than in all control groups (28.20 ± 7.34.25, 49 ± 12.47, 26.37 ± 9.77 mcg/L, respectively) (P= 0.05). UCL in group 1 and group 2 subjects (11.44 ± 6.88 and 15.68 ± 6.75 mcg/L, respectively) was significantly lower than in group 3 subjects (28.83 ± 9.37 mcg/L) (P < 0.05). There were significant correlations between length, bodyweight and PCL in the group 1 subjects (r = 0.42, P= 0.22 and r = 0.53, P= 0.03, respectively). There was a negative correlation between plasma glucose and UCL, which was not statistically significant in group 2 subjects (r =-0.4, P= 0.061). CONCLUSION: There was a negative chromium balance in type 1 diabetics. This negative balance may affect the insulin function badly. If this negative balance should be confirmed by recent studies we suggest that chromium supplementation with insulin is necessary for type 1 diabetes.

Relationship between metabolic control and neurocognitive functions in children diagnosed with type I diabetes mellitus before and after 5 years of age.

We aimed to investigate the effects of age onset of diabetes, glycemic control and frequency of hypoglycemia on neurocognitive functions in type I diabetic children. Sixty type I diabetic children with diagnosis before (Group 1) or after (Group 2) five years of age and 40 healthy children were tested. Wechsler Intelligence Scale for Children Revised (WISC-R), Stroop Test, and Visual Auditory Digit Span Test Form B were applied to all children in the two groups. Neurocognitive functions such as visual perception, short-term memory and selective attention were seen to be negatively affected at a significant level. Group 1 patients with poor glycemic control were found to have significant dysfunction in verbal, performance and general intelligence. Neurocognitive functions were negatively affected by early onset of diagnosis, poor glycemic control and frequent hypoglycemia in children with type I diabetes mellitus. We suggest that negative effects on neurocognitive functions in type I diabetes should be considered in the follow-up of these patients.

The utility of annual growth velocity standard deviation scores and measurements of biochemical parameters in long-term treatment monitoring of children with 21-hydroxylase deficiency.

PURPOSE: This study aimed to investigate the utility of annual growth velocity (GV) standard deviation scores (SDSs) and compatibility and effectiveness of biochemical parameters in long-term treatment monitoring and management of 21-hydroxylase deficiency (21-OHD) in children. METHODS: Fifty children with 21-OHD were included in this study, and the biochemical parameters obtained during 402 visits were retrospectively evaluated. The follow-up period was divided between two GV SDS groups (GV SDS < 2 and GV SDS ≥ 2) and compared with auxological, biochemical, and clinical findings. RESULTS: Elevation of 17-hydroxyprogesterone (17-OHP) values was observed at 193/402 visits, and both adrenocorticotropic hormone (ACTH) and total testosterone (tT) were observed at 53 of 193 (27.5%) visits. The calculated cut-off value for 17-OHP was > 4.3 ng/ml, with a sensitivity of 85.48% and specificity of 37.59% in the GV SDS ≥ 2 group. In the GV SDS ≥ 2 group, the corrected final height SDS (cFH SDS) was lower, and the delta height was higher than in the GV SDS < 2 group (p = 0.005 and p = 0.008, respectively). Linear regression analysis of the GV SDSs revealed that 17-OHP values and the hydrocortisone dose (mg/m2) were affected (ß = 0.037, p = 0.035, and ß = - 0.147, p = 0.001, respectively). CONCLUSIONS: Annual GV was critical in the final height (FH) of children with 21-OHD. However, we observed inconsistency between the biochemical parameters in the follow-ups, and there were difficulties in evaluating these markers. Therefore, annual GV SDSs and biochemical findings should be used together in patients with 21-OHD at follow-ups.

PLXNB1 mutations in the etiology of idiopathic hypogonadotropic hypogonadism.

Idiopathic hypogonadotropic hypogonadism (IHH) comprises a group of rare genetic disorders characterized by pubertal failure caused by gonadotropin-releasing hormone (GnRH) deficiency. Genetic factors involved in semaphorin/plexin signaling have been identified in patients with IHH. PlexinB1, a member of the plexin family receptors, serves as the receptor for semaphorin 4D (Sema4D). In mice, perturbations in Sema4D/PlexinB1 signaling leads to improper GnRH development, highlighting the importance of investigating PlexinB1 mutations in IHH families. In total, 336 IHH patients (normosmic IHH, n = 293 and Kallmann syndrome, n = 43) from 290 independent families were included in the present study. Six PLXNB1 rare sequence variants (p.N361S, p.V608A, p.R636C, p.V672A, p.R1031H, and p.C1318R) are described in eight normosmic IHH patients from seven independent families. These variants were examined using bioinformatic modeling and compared to mutants reported in PLXNA1. Based on these analyses, the variant p.R1031H was assayed for alterations in cell morphology, PlexinB1 expression, and migration using a GnRH cell line and Boyden chambers. Experiments showed reduced membrane expression and impaired migration in cells expressing this variant compared to the wild-type. Our results provide clinical, genetic, molecular/cellular, and modeling evidence to implicate variants in PLXNB1 in the etiology of IHH.

A homozygous recurring mutation in WISP3 causing progressive pseudorheumatoid arthropathy.

WISP3 is a member of the CCN (for CTGF, CYR61, and NOV) gene family, which encodes cysteine-rich secreted proteins with roles in cell growth and differentiation. Mutations in the WISP3 gene are associated with the autosomal recessive skeletal disorder, also known as progressive pseudorheumatoid arthropathy of childhood (PPAC). We diagnosed three siblings from a non-consanguineous family with PPAC. The patients were asymptomatic in early childhood. Signs and symptoms of disease that include progressive joint stiffness, swelling of the finger joints, and osteopenia, and slow linear growth developed between 2 and 8 years of age. PCR amplification and direct sequencing of the WISP3 gene revealed a homozygous mutation at nucleotide 156 of the WISP3 gene, resulting in a Cys52-to-ter substitution. This mutation has previously been reported in French, Italian, and Arab families. Interestingly, the C52X mutation was found to be associated with a c.248G-->A (G83E) variation, suggesting the existence of a founder effect. By contrast, the presence of the same aberration in three different ethnic groups could imply that this particular site is prone to mutation. Basal fasting concentrations of growth hormone, insulin-like growth factor-1, and insulin-like growth factor binding protein-3, as well as glucose and insulin levels revealed no aberrations. In conclusion, consideration of this rare disease that causes significant morbidity with short stature, osteopenia and arthritic complaints would prevent unnecessary examinations and treatment attempts. Testing for this specific mutation in suspected cases could provide a rapid and definitive diagnosis.

Changes in the presentation of newly diagnosed type 1 diabetes in children during the COVID-19 pandemic in a tertiary center in Southern Turkey.

OBJECTIVES: The COVID-19 pandemic is a global health problem with high morbidity and mortality. This study aimed to investigate patients who were diagnosed with type 1 diabetes during the pandemic and evaluate the effect of the pandemic on the clinical findings of these patients by comparing them with findings from a year prior. METHODS: Patients diagnosed with type 1 diabetes mellitus between 2019 and 2021 were separated into two groups: Patients diagnosed prepandemic and those diagnosed during the pandemic. RESULTS: The number of newly diagnosed diabetes cases increased from 46 in the prepandemic period to 74 in the pandemic period. The number of cases diagnosed with diabetic ketoacidosis (DKA) in the clinic increased from 58.7 to 91.9%. We found that moderate and severe DKA rates from 18.5 and 14.8% to 23.5 and 22.1%, respectively. Besides, the average HbA1c was higher, while the average bicarbonate was lower in cases diagnosed during the pandemic period compared to the prepandemic period (p=0.048 and p<0.001, respectively). We found that celiac autoantibody positivity antibodies to glutamic acid decarboxylase (anti GAD) positivity, and islet cell antibodies (ICA), ICA and anti GAD positivity coexistence were higher (p=0.045, p=0.008, and p=0.007, respectively) among the patients diagnosed during the pandemic. CONCLUSIONS: We observed an increase in the number of patients newly diagnosed with type 1 diabetes mellitus, an increase in autoantibody positivity, and higher rates and severity of DKA during the COVID-19 pandemic period compared to the prepandemic period.

DLG2 Mutations in the Etiology of Pubertal Delay and Idiopathic Hypogonadotropic Hypogonadism.

INTRODUCTION: Idiopathic hypogonadotropic hypogonadism (IHH) is caused by dysfunction of the hypothalamic-pituitary-gonadal axis. DLG2 was recently implicated as a gene associated with delayed puberty and which may also contribute to IHH. The confirmation of the candidate puberty genes in independent IHH cohorts has become crucial due to the lack of proper genotype-phenotype segregations in reported pedigrees. Therefore, we aimed to screen DLG2 in patient variants in a large cohort of IHH patients. METHODS: The present study included a total of 336 IHH patients from 290 independent families. The coding and flanking regions of DLG2 were screened for potentially important variants in the WES data. Candidate variants were evaluated in the -gnomAD and GME databases according to their allele frequencies, and only those with a frequency <0.0001 were considered rare. Detected variants were classified according to the ACMG/AMP criteria. RESULTS: We found 1 homozygous and 2 heterozygous missense variants in 3 independent pedigrees. Identified variants were found extremely rare or not reported in gnomAD. Two variants were categorized as "uncertain significance," and the other one was "likely pathogenic" according to the ACMG criteria. All patients were normosmic, and in 2 of the 3 families, there were no causal variants in other IHH-related genes. CONCLUSION: We detected 3 rare sequencing variants in DLG2 in 5 patients with IHH or delayed puberty in a large IHH cohort. Our results support the contention that the DLG2 mutations are associated with IHH in human puberty.