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.

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.

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.

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.

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.

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.

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.

Experience with the targeted next-generation sequencing in the diagnosis of hereditary hypophosphatemic rickets.

OBJECTIVES: Hereditary Hypophosphatemic Rickets (HHR) is a heterogeneous group of disorders characterized by hypophosphatemia. Although the X-linked dominant HHR is the most common form, the genetic etiology of HHR is variable. Recently, developed next-generation sequencing techniques may provide opportunities for making HHR diagnosis in a timely and efficient way. METHODS: We investigated clinical and genetic features for 18 consecutive probands and their 17 affected family members with HHR. All patient's clinical and biochemical data were collected. We first analyzed a single gene with Next-generation sequencing if the patients have a strong clue for an individual gene. For the remaining cases, a Hypophosphatemic Rickets gene panel, including all known HHR genes by Next-generation sequencing, was employed. RESULTS: We were able to diagnosis all of the consecutive 35 patients in our tertiary care center. We detected nine novel and 10 previously described variants in PHEX (9; 50%), SLC34A3 (3; 17%), ENPP1 (3; 17%), SLC34A1 (1; 5%), CLCN5 (1; 5%), and DMP1 (1; 5%). CONCLUSIONS: To delineate the etiology of HHR cases in a cost and time-efficient manner, we propose single gene analysis by next-generation sequencing if findings of patients indicate a strong clue for an individual gene. If that analysis is negative or for all other cases, a Next-generation Sequence gene panel, which includes all known HHR genes, should be employed.

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.

Clinical Characteristics of 46,XX Males with Congenital Adrenal Hyperplasia

Objective: To retrospectively evaluate the follow-up data in patients with 46,XX congenital adrenal hyperplasia (CAH) who were raised male. Methods: A national database was created. The data of patients were asked to be recorded in the data form. Results: The median (range) age of diagnosis was three (0.1-18.3) years in 44 patients. Twenty nine cases were diagnosed after the age of two years. Most (95.4%) cases were stage 4-5 virilized. Hysterectomy and bilateral salpingoopherectomy, at a median age of 7.25 (2.4-25.3) years, was performed in 35 cases. Testicular prostheses were placed in 11 (25%) cases at a median age of 11.2 (2.8-17) years. The median final height was 149.2 (132.8-172) cms in 38 patients, including simple virilizing (n=18), salt-wasting (n=6), and 11-beta hydroxylase (n=12). Of the 16 patients above the age of eighteen, university education was completed in 25%. Conclusion: It was seen that most (65.9%) of the 46,XX CAH cases raised male were diagnosed after two years of age. In these cases, hysterectomy and bilateral salpingoopherectomy, genital corrective surgeries and testicular prosthesis operations were performed in a very wide age rage.

Clinical Characteristics and Long-term Follow-up of Patients with Diabetes Due To PTF1A Enhancer Mutations.

CONTEXT: Biallelic mutations in the PTF1A enhancer are the commonest cause of isolated pancreatic agenesis. These patients do not have severe neurological features associated with loss-of-function PTF1A mutations. Their clinical phenotype and disease progression have not been well characterized. OBJECTIVE: To evaluate phenotype and genotype characteristics and long-term follow-up of patients with PTF1A enhancer mutations. SETTING: Twelve tertiary pediatric endocrine referral centers. PATIENTS: Thirty patients with diabetes caused by PTF1A enhancer mutations. Median follow-up duration was 4 years. MAIN OUTCOME MEASURES: Presenting and follow-up clinical (birthweight, gestational age, symptoms, auxology) and biochemical (pancreatic endocrine and exocrine functions, liver function, glycated hemoglobin) characteristics, pancreas imaging, and genetic analysis. RESULTS: Five different homozygous mutations affecting conserved nucleotides in the PTF1A distal enhancer were identified. The commonest was the Chr10:g.23508437A>G mutation (n = 18). Two patients were homozygous for the novel Chr10:g.23508336A>G mutation. Birthweight was often low (median SDS = -3.4). The majority of patients presented with diabetes soon after birth (median age of diagnosis: 5 days). Only 2/30 presented after 6 months of age. All patients had exocrine pancreatic insufficiency. Five had developmental delay (4 mild) on long-term follow-up. Previously undescribed common features in our cohort were transiently elevated ferritin level (n = 12/12 tested), anemia (19/25), and cholestasis (14/24). Postnatal growth was impaired (median height SDS: -2.35, median BMI SDS: -0.52 SDS) with 20/29 (69%) cases having growth retardation. CONCLUSION: We report the largest series of patients with diabetes caused by PTF1A enhancer mutations. Our results expand the disease phenotype, identifying recurrent extrapancreatic features which likely reflect long-term intestinal malabsorption.

Gender Identity and Assignment Recommendations in Disorders of Sex Development Patients: 20 Years' Experience and Challenges

Objective: Gender assignment in infants and children with disorders of sex development (DSD) is a stressful situation for both patient/families and medical professionals. Methods: The purpose of this study was to investigate the results of gender assignment recommendations in children with DSD in our clinic from 1999 through 2019. Results: The mean age of the 226 patients with DSD at the time of first admission were 3.05±4.70 years. 50.9% of patients were 46,XY DSD, 42.9% were 46,XX DSD and 6.2% were sex chromosome DSD. Congenital adrenal hyperplasia (majority of patients had 21-hydroxylase deficiency) was the most common etiological cause of 46,XX DSD. In 46,XX patients, 87 of 99 (89.7%) were recommended to be supported as a female, 6 as a male, and 4 were followed up. In 46,XY patients, 40 of 115 (34.8%) were recommended to be supported as a female, and 70 as male (60.9%), and 5 were followed up. In sex chromosome DSD patients, 3 of 14 were recommended to be supported as a female, 9 as a male. The greatest difficulty in making gender assignment recommendations were in the 46,XY DSD group. Conclusion: In DSD gender assignment recommendations, the etiologic diagnosis, psychiatric gender orientation, expectation of the family, phallus length and Prader stage were effective in the gender assignment in DSD cases, especially the first two criteria. It is important to share these experiences among the medical professionals who are routinely charged with this difficult task in multidisciplinary councils.

Mutations Within the Transcription Factor PROP1 in a Cohort of Turkish Patients with Combined Pituitary Hormone Deficiency

Objective: Mutations of the genes encoding transcription factors which play important roles in pituitary morphogenesis, differentiation and maturation may lead to combined pituitary hormone deficiency (CPHD). PROP1 gene mutations are reported as the most frequent genetic aetiology of CHPD. The aim of this study was to describe the phenotypes of Turkish CPHD patients and define the frequency of PROP1 mutations. Methods: Fifty-seven CPHD patients from 50 families were screened for PROP1 mutations. The patients were affected by growth hormone (GH) and additional anterior pituitary hormone deficiencies. Results: All patients had GH deficiency. In addition, 98.2% had central hypothyroidism, 45.6% had hypogonadotropic hypogonadism, 43.8% had adrenocorticotropic hormone deficiency and 7.1% had prolactin deficiency. Parental consanguinity rate was 50.9% and 14 cases were familial. Mean height standard deviation score (SDS) and weight SDS were -3.8±1.4 and -3.1±2.0, respectively. Of 53 patients with available pituitary imaging, 32 (60.4%) showed abnormalities. None had extra-pituitary abnormalities. Eight index patients had PROP1 gene mutations. Five sporadic patients were homozygous for c.301_302delAG (p.Leu102CysfsTer8) mutation, two siblings had exon 2 deletion, two siblings had complete gene deletion and two siblings were homozygous for the novel c.353A>G (p.Q118R) mutation. The frequency of the PROP1 mutations was 16% in our cohort. Mutation rate was significantly higher in familial cases compared to sporadic cases (42.8% vs 11.6%; p<0.01). Conclusion: Phenotype of patients regarding hormonal deficiencies, pituitary morphology, presence of extra-pituitary findings, family history of CPHD and parental consanguinity are important for deciding which pituitary transcription factor deficiency should be investigated. PROP1 mutation frequencies vary in different populations and its prevalence is high in Turkish CPHD patients.

21-Hydroxylase deficiency: Mutational spectrum and Genotype-Phenotype relations analyses by next-generation sequencing and multiplex ligation-dependent probe amplification.

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD) is autosomal recessive disorder of cortisol biosynthesis. Genetic defects in CYP21A2 cause 21OHD. The aim of this study was to determine spectrum of mutations in CYP21A2 in a large cohort and analyze the genotype-phenotype correlation to assess predictive characteristics of genotype. We investigated a total of 113 patients with 21OHD. Next-generation sequencing and Multiplex ligation-dependent probe amplification of the CYP21A2 gene were performed in patients and their parents. The genotypes were categorized into Groups 0, A, B, and C according to the residual 21-hydroxylase activities. In this study, the group A was divided into two subgroups as A1 and A2. Three novel variants were found. The genotype-phenotype correlation of the mutation classification was 91.5%. Positive predictivity of subgroups A1 was higher than groups A and subgroups A2. Our study reports genotype-phenotype correlations in the largest 21OHD cohort in Turkey. This correlation sustained when we analyzed our data in combination with metadata from other published studies. This study confirms that CYP21A2 genotyping with next-generation sequencing and MLPA can accurately and reliably confirm the diagnosis of 21OHD. We propose a new classification by dividing group A into two new subgroups to better predict the phenotype. In light of this very high genotype-phenotype correlation, with their ever-increasing availability, declining cost, and turnaround time, we propose that molecular genetic studies can be more economical and practical alternative to the current initial diagnostic laboratory studies based on assays of intermediary steroid metabolites.

Determination of cerebral edema with serial measurement of optic nerve sheath diameter during treatment in children with diabetic ketoacidosis: a longitudinal study.

Background Cerebral edema is a fatal complication that can occur in children with diabetic ketoacidosis (DKA). Its clinical signs are generally not explicit, and subclinical cerebral edema can occur. This study is one of the few longitudinal studies conducted to identify cerebral edema in patients with DKA by measuring the optic nerve sheath diameter (ONSD). The aim of this study was to investigate cerebral edema in children with DKA with serial measurement of ONSD, which is an early and reliable indicator of cerebral edema, and to monitor changes in ONSD during therapy. Methods The study was conducted by measuring ONSD ultrasonographically at baseline and during the course of therapy in patients with DKA. All participants were diagnosed and received therapy at our unit between May 2016 and June 2017. The study was registered with the Clinical Trials database, with a study number of NCT02937441. Measurements were obtained while the patients were in the supine position with their eyes closed, and axial transbulbar images of both eyes were obtained with a 6-15-MHz linear probe. Results The ONSD values of children with DKA changed during the treatment, reaching the highest values at 12-16 h of therapy, and the greatest ONSD was observed in children who had moderate and severe DKA. Conclusions During treatment of children with DKA, it is possible to predict cerebral edema by measuring ONSD, and this may contribute to clinical management, especially fluid treatment.

Predicted Benign and Synonymous Variants in CYP11A1 Cause Primary Adrenal Insufficiency Through Missplicing.

Primary adrenal insufficiency (PAI) is a potentially life-threatening condition that can present with nonspecific features and can be difficult to diagnose. We undertook next generation sequencing in a cohort of children and young adults with PAI of unknown etiology from around the world and identified a heterozygous missense variant (rs6161, c.940G>A, p.Glu314Lys) in CYP11A1 in 19 individuals from 13 different families (allele frequency within undiagnosed PAI in our cohort, 0.102 vs 0.0026 in the Genome Aggregation Database; P < 0.0001). Seventeen individuals harbored a second heterozygous rare disruptive variant in CYP11A1 and two had very rare synonymous changes in trans (c.990G>A, Thr330 = ; c.1173C>T, Ser391 =). Although p.Glu314Lys is predicted to be benign and showed no loss-of-function in an Escherichia coli assay system, in silico and in vitro studies revealed that the rs6161/c.940G>A variant, plus the c.990G>A and c.1173C>T changes, affected splicing and that p.Glu314Lys produces a nonfunctional protein in mammalian cells. Taken together, these findings show that compound heterozygosity involving a relatively common and predicted "benign" variant in CYP11A1 is a major contributor to PAI of unknown etiology, especially in European populations. These observations have implications for personalized management and demonstrate how variants that might be overlooked in standard analyses can be pathogenic when combined with other very rare disruptive changes.

Hyperphosphatemic Familial Tumoral Calcinosis in Two Siblings with a Novel Mutation in GALNT3 Gene: Experience from Southern Turkey

Inactivating autosomal recessive mutations in fibroblast growth factor 23 (FGF23), klotho (KL) and polypeptide N-acetylgalactosaminotransferase 3 (GALNT3) genes lead to a rare disorder, hyperphosphatemic familial tumoral calcinosis (HFTC). Patients with HFTC present with hyperphosphatemia and tumor like soft tissue calcifications. Although 78% of patients develop their first symptoms between the ages of 2-13 years, diagnosis is usually delayed until adulthood. Some individuals with the same genetic defect develop a condition named hyperphosphatemic hyperostosis syndrome. Herein we report two siblings suffering from periarticular, warm, hard and tender subcutaneous masses. Subcutaneous calcifications were present on X-ray and biopsy results were consistent with calcinosis in both patients. Laboratory results showed marked hyperphosphatemia and elevated renal tubular phosphate reabsorption rates, normal renal function tests and normal serum 25-hydroxyvitamin D levels. Thus, we suspected HFTC and performed next generation sequencing for the GALNT3 gene, reported as the most frequent cause. A novel homozygote P85Rfs*6 (c.254_255delCT) mutation in GALNT3 was identified in both siblings. Our report adds two new patients to the literature about this rare genetic disease and suggests that small deletions in the GALNT3 gene may be related with HFTC phenotype.

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.

Efficiency of Single Dose of Tolvaptan Treatment During the Triphasic Episode After Surgery for Craniopharyngioma

Inappropriate antidiuretic hormone syndrome (SIADH) may develop after intracranial surgery. SIADH in the pediatric age group is usually encountered in patients with an intracranial mass both before and after surgery. Fluid restriction is the standard therapy in SIADH. However, a resistant, hyponatremic pattern may be encountered in some cases. Vaptans have been recently introduced for treatment of hyponatremia due to SIADH. There is inadequate data concerning tolvaptan treatment in pediatric patients. We present a 13 year-old female with SIADH of triphasic episode who was transferred to our clinic after surgery for craniopharyngioma. Resistant hyponatremia did not resolve despite fluid restriction and hypertonic saline support. The patient responded rapidly to a single dose of tolvaptan, with no adverse effect, which resulted in successful control of her SIADH.