Molecular analysis of MKRN3 gene in Turkish girls with sporadic and familial idiopathic central precocious puberty.

OBJECTIVES: Central precocious puberty (CPP) develops as a result of early stimulation of the hypothalamic-pituitary-gonadal (HPG) axis. The loss-of-function mutations in the Makorin-ring-finger3 (MKRN3) gene appear to be the most common molecular cause of familial CPP. We aimed to identify MKRN3 gene mutations in our CPP cohort and to investigate the frequency of MKRN3 mutations. METHODS: 102 patients with CPP included. 53 of them had family history of CPP in the first and/or second-degree relatives. MKRN3 gene was analyzed by next-generation sequencing. RESULTS: Possible pathogenic variants were found in 2/53 patients with family history of CPP (3.8%) and 1/49 patient without family history (2%). A novel heterozygous c.1A>G (p.Met1Val) mutation, a novel heterozygous c.683_684delCA (p.Ser228*) and a previously reported c.482dupC (Ala162Glyfs*) frameshift variations were detected. The two novel variants are predicted to be pathogenic in silico analyses. CONCLUSIONS: In our cohort, possible pathogenic variants in MKRN3 gene were detected in 2.9% of the total cohort, 3.8% of the familial and 2% of the nonfamilial cases, slightly lower than that reported in the literature. Two novel variants detected contribute to the molecular repertoire of MKRN3 defects in CPP. Classical pattern of paternal inheritance has been demonstrated in all three cases. However, the father of the patient 3 did not have history of CPP suggesting that the father inherited this variant from his mother and had phenotype skipping. Therefore, we emphasize that the absence of history of CPP in the father does not exclude the possibility of a MKRN3 mutation.

Challenges in the Management of a 7-Year-Old Child with Thyrotropin-Secreting Pituitary Adenoma and the Review of the Literature.

INTRODUCTION: Thyrotropin-producing pituitary adenoma (TSHoma) is a very rare disease, representing less than 1% of the pituitary tumours and presenting with elevated thyroid hormones and normal/high TSH concentrations. CASE PRESENTATION: A 7-year-old boy with nervousness was referred by his psychiatrist for elevated free T4, T3, and TSH levels. Initial evaluation revealed an elevated α-subunit. Pituitary magnetic resonance imaging (MRI) demonstrated a macroadenoma. The patient underwent a trans-sphenoidal tumour resection (TSS) which showed positive immunohistochemical staining for TSH, growth hormone, and prolactin in tumoral tissue. Euthyroidism was achieved for 1 year after TSS, then recurrence of tumour with elevated TSH and thyroid hormone levels necessitated a re-operation with TSS followed by gamma-knife radiosurgery. The euthyroid state was achieved and lasted for 2.5 years this time, but due to the recurrence, medical treatment had been commenced with cabergoline and octreotide. Euthyroidism was maintained for the last 4 years on monthly octreotide treatment. A repeat MRI demonstrated no pituitary mass, but a mass in the sphenoidal sinus had been detected. Removal of this mass by surgery did not achieve euthyroidism. 68Ga-DOTA-TATE positron emission tomography/computed tomography showed residual tissue extending from the pituitary region to the sphenoid sinus. The patient's bone age was advanced by 2 years at diagnosis which became 4 years in 1 year after the diagnosis and remained so throughout follow-up, leading to a final height of -3.3 SDS below his target height at the age of 16 years. CONCLUSION: The diagnosis, treatment, and follow-up of TSHomas are challenging, and short stature due to accelerated bone maturation is a complication of paediatric TSHomas.

A novel deletion involving the first GNAS exon encoding Gsα causes PHP1A without methylation changes at exon A/B.

Individuals affected by pseudohypoparathyroidism type 1A (PHP1A) display hyperphosphatemia and hypocalcemia despite elevated PTH levels, as well as features of Albright Hereditary Osteodystrophy (AHO). PHP1A is caused by variants involving the maternal GNAS exons 1-13 encoding the stimulatory G protein α-subunit (Gsα). MLPA and aCGH analysis led in a male PHP1A patient to identification of a de novo 1284-bp deletion involving GNAS exon 1. This novel variant overlaps with a previously identified 1438-bp deletion in another PHP1A patient (ref. Li et al. (2020) [13], patient 2) that extends from the exon 1 promoter into the up-stream intronic region. This latter deletion is associated with reduced methylation at GNAS exon A/B, i.e. the differentially methylated region (DMR) that is demethylated in most pseudohypoparathyroidism type 1B (PHP1B) patients. In contrast, genomic DNA from our patient revealed no evidence for an epigenetic GNAS defect as determined by MS-MLPA and pyrosequencing. These findings thus reduce the region, which, in addition to other nucleotide sequences telomeric of exon A/B, may undergo histone modifications or interacts with transcription factors and possibly as-yet unknown proteins that are required for establishing the maternal methylation imprints at this site. Taken together, nucleotide deletions or changes within an approximately 1300-bp region telomeric of exon A/B could be a cause of PHP1B variants with complete or incomplete loss-of-methylation at the exon A/B DMR. In addition, when investigating patients with suspected PHP1A, MLPA should be considered to search for structural abnormalities within this difficult to analyze genomic region comprising GNAS exon 1.

Efficacy of the Novel Degludec/Aspart Insulin Co-formulation in Children and Adolescents with Type 1 Diabetes: A Real-life Experience with One Year of IDegAsp Therapy in Poorly Controlled and Non-compliant Patients

Objective: To evaluate the efficacy of degludec/aspart (IDegAsp) insulin co-formulation in children and adolescents with poorly controlled type 1 diabetes (T1DM). Methods: Patients with poorly controlled T1DM on basal-bolus insulin regimes and having compliance problems related to insulin injections were switched to IDegAsp and were included. Data on hemoglobin A1c (HbA1c) levels, hypoglycemic episodes, frequency of diabetic ketoacidosis (DKA) and insulin doses were recorded at baseline and after one year of IDegAsp treatment. Results: Fifty patients (22 girls; 44%) were started on IDegAsp. The mean±standard deviation (range) age and duration of diabetes were 12.9±3.4 (4-18) and 5.2±3.1 (1.0-13.7) years, respectively. At the end of one year, 38 patients were still on IDegAsp, whereas 12 patients had opted to resume their original treatments. In those who continued on IDegAsp, HbA1c levels did not change, but the number of self-reported mild-moderate hypoglycemic episodes decreased significantly (p<0.05). In the year before switching to IDegAsp, 11 DKA attacks in 9 patients were observed, whereas this decreased to 4 DKA attacks in 4 patients after one year of IDegAsp therapy (p=0.06). Conclusion: IDegAsp regimen may improve clinical management in poorly controlled basal-bolus insulin regimen T1DM patients who have frequent hypoglycemia and DKA attacks, as well as in those with poor compliance with multiple injections. Although a simplified basal-bolus IDegAsp regimen is an attractive option for patients with T1DM, some may not adapt to this treatment due to the fixed IAsp dose of IDegAsp.

Catch-up Growth and Discontinuation of Fludrocortisone Treatment in Aldosterone Synthase Deficiency.

BACKGROUND: Aldosterone synthase deficiency (ASD) caused by mutations in the CYP11B2 gene is characterized by isolated mineralocorticoid deficiency. Data are scarce regarding clinical and biochemical outcomes of the disease in the follow-up. OBJECTIVE: Assessment of the growth and steroid profiles of patients with ASD at the time of diagnosis and after discontinuation of treatment. DESIGN AND METHOD: Children with clinical diagnosis of ASD were included in a multicenter study. Growth and treatment characteristics were recorded. Plasma adrenal steroids were measured using liquid chromatography-mass spectrometry. Genetic diagnosis was confirmed by CYP11B2 gene sequencing and in silico analyses. RESULTS: Sixteen patients from 12 families were included (8 females; median age at presentation: 3.1 months, range: 0.4 to 8.1). The most common symptom was poor weight gain (56.3%). Median age of onset of fludrocortisone treatment was 3.6 months (range: 0.9 to 8.3). Catch-up growth was achieved at median 2 months (range: 0.5 to 14.5) after treatment. Fludrocortisone could be stopped in 5 patients at a median age of 6.0 years (range: 2.2 to 7.6). Plasma steroid profiles revealed reduced aldosterone synthase activity both at diagnosis and after discontinuation of treatment compared to age-matched controls. We identified 6 novel (p.Y195H, c.1200 + 1G > A, p.F130L, p.E198del, c.1122-18G > A, p.I339_E343del) and 4 previously described CYP11B2 variants. The most common variant (40%) was p.T185I. CONCLUSIONS: Fludrocortisone treatment is associated with a rapid catch-up growth and control of electrolyte imbalances in ASD. Decreased mineralocorticoid requirement over time can be explained by the development of physiological adaptation mechanisms rather than improved aldosterone synthase activity. As complete biochemical remission cannot be achieved, a long-term surveillance of these patients is required.

Broad-spectrum XX and XY gonadal dysgenesis in patients with a homozygous L193S variant in PPP2R3C.

CONTEXT: Homozygous and heterozygous variants in PPP2R3C are associated with syndromic 46,XY complete gonadal dysgenesis (Myo-Ectodermo-Gonadal Dysgenesis (MEGD) syndrome), and impaired spermatogenesis, respectively. This study expands the role of PPP2R3C in the aetiology of gonadal dysgenesis (GD). METHOD: We sequenced the PPP2R3C gene in four new patients from three unrelated families. The clinical, laboratory, and molecular characteristics were investigated. We have also determined the requirement for Ppp2r3c in mice (C57BL6/N) using CRISPR/Cas9 genome editing. RESULTS: A homozygous c.578T>C (p.L193S) PPP2R3C variant was identified in one 46,XX girl with primary gonadal insufficiency, two girls with 46,XY complete GD, and one undervirilised boy with 46,XY partial GD. The patients with complete GD had low gonadal and adrenal androgens, low anti-Müllerian hormone, and high follicle-stimulating hormone and luteinizing hormone concentrations. All patients manifested characteristic features of MEGD syndrome. Heterozygous Ppp2r3c knockout mice appeared overtly normal and fertile. Inspection of homozygous embryos at 14.5, 9.5, and 8.5 days post coitum(dpc) revealed evidence of dead embryos. We conclude that loss of function of Ppp2r3c is not compatible with viability in mice and results in embryonic death from 7.5 dpc or earlier. CONCLUSION: Our data indicate the essential roles for PPP2R3C in mouse and human development. Germline homozygous variants in human PPP2R3C are associated with distinctive syndromic GD of varying severity in both 46,XY and 46,XX individuals.

Dysgenesis and Dysfunction of the Pancreas and Pituitary Due to FOXA2 Gene Defects.

CONTEXT: Developmental disorders of the pituitary gland leading to congenital hypopituitarism can either be isolated or associated with extrapituitary abnormalities (syndromic hypopituitarism). A large number of syndromic hypopituitarism cases are linked to mutations in transcription factors. The forkhead box A2 (FOXA2) is a transcription factor that plays a key role in the central nervous system, foregut, and pancreatic development. OBJECTIVE: This work aims to characterize 2 patients with syndromic hypopituitarism due to FOXA2 gene defects. RESULTS: We report a novel heterozygous nonsense c.616C > T(p.Q206X) variant that leads to a truncated protein that lacks part of the DNA-binding domain of FOXA2, resulting in impaired transcriptional activation of the glucose transporter type 2 (GLUT2)-luciferase reporter. The patient is the sixth patient described in the literature with a FOXA2 mutation, and the first patient exhibiting pancreatic hypoplasia. We also report a second patient with a novel de novo 8.53 Mb deletion of 20p11.2 that encompasses FOXA2, who developed diabetes mellitus that responded to sulfonylurea treatment. CONCLUSION: Our 2 cases broaden the molecular and clinical spectrum of FOXA2-related disease, reporting the first nonsense mutation and the first case of pancreatic dysgenesis.

Does Genotype-Phenotype Correlation Exist in Vitamin D-Dependent Rickets Type IA: Report of 13 New Cases and Review of the Literature.

Vitamin D-dependent rickets type IA (VDDR-IA) is caused by biallelic mutations in CYP27B1. Data regarding genotype-phenotype correlation in VDDR-IA are scarce. Here, we aimed to investigate clinical/genotypic features and long-term follow-up of 13 new cases with VDDR-IA and genotype-phenotype correlation of reported cases in the literature. Thirteen patients with VDDR-IA were evaluated. Eight patients had reached their final height at the time of the study and, for whom, long-term outcome data were analyzed. Further, all VDDR-IA patients in the literature (n:183) were analyzed and clinical-genetic features were recorded. The median age of diagnosis was 2.55 ± 1.13 (1.0-12) years. Initial diagnoses before referral to our clinic were nutritional rickets (n:7), hypophosphatemic rickets (n:2), and pseudohypoparathyroidism (n:1). All had biochemical evidence suggestive of VDDR-IA; except one with elevated 1,25(OH)2D3 and another with hyperphosphatemia, in whom pseudohypoparathyroidism was excluded with molecular tests. Combined analyses of our cohort and other series in the literature demonstrated that three most common CYP27B1 mutations are p.F443Pfs*24, c.195 + 2T > G, and p.V88Wfs*71. In Turkish population, p.K192E mutation along with the former two is the most common mutations. Comparison of clinical features demonstrated that c.195 + 2T > G mutation causes the most severe and p.K192E mutation causes the least severe phenotype with respect to age and height at presentation and calcitriol requirement. We found a clear genotype-phenotype correlation in VDDR-IA, notably CYP27B1 intronic c.195 + 2T > G mutation causes a more severe phenotype with lower height SDS at presentation and, higher calcitriol requirement, while less severe phenotype occurs in p.K192E mutation.

A Rare Cause of Hypophosphatemia: Raine Syndrome Changing Clinical Features with Age.

Raine Syndrome (RS) is caused by biallelic loss-of-function mutations in FAM20C gene and characterized by hypophosphatemia, typical facial and skeletal features. Subperiosteal bone formation and generalized osteosclerosis are the most common radiological findings. Here we present a new case with RS. A 9-month-old male patient on a home-type ventilator was referred for hypophosphatemia. He was born with a weight of 3800 g to non-consanguineous parents. Prenatal ultrasound had demonstrated nasal bone agenesis. A large anterior fontanel, frontal bossing, exophthalmos, hypoplastic nose, high arched palate, low set ears, triangular mouth, and corneal opacification were detected on physical examination. Serial skeletal X-rays revealed diffuse osteosclerosis at birth which was gradually decreased by the age of 5 months with subperiosteal undermineralized bone formation and medullary space of long bone could be distinguishable with bone-within-a-bone appearance. At 9 months of age, hand X-ray revealed cupping of the ulna with loose radial bone margin with minimal fraying and osteopenia. Cranial computed tomography scan showed bilateral periventricular calcification and hydrocephalus in progress. The clinical, laboratory, and radiological examinations were consistent with RS. Molecular analyses revealed a compound heterozygous mutation in FAM20C gene (a known pathogenic mutation, c.1645C > T, p.Arg549Trp; and a novel c.863 + 5 G > C variant). The patient died due to respiratory failure at 17 months of age. This case allowed us to demonstrate natural progression of skeletal features in RS. Furthermore, we have described a novel FAM20C variant causing RS. Previous literature on RS is also reviewed.

Total oxidant and antioxidant status and paraoxonase 1 levels of children with noncystic fibrosis bronchiectasis

Background/aim: To evaluate total oxidant status (TOS), total antioxidant capacity (TAC), and paraoxonase 1 (PON1) levels in children with noncystic fibrosis (CF) bronchiectasis (BE), and to compare these levels with those of healthy controls. The study parameters were also evaluated according to some demographic, anthropometric, and clinical characteristics, as well as lung functions. Materials and methods: Enrolled in the study were 118 children with non-CF BE and 68 healthy controls. Serum TOS, TAC, and PON1 levels were determined. Lung function tests were performed by spirometry. Results: Serum TOS was higher in the patients [median 9.54 (IQR 25­75 = 7.05­13.30) µmol H2O2 Eq/L] than in the healthy subjects [6.64 (5.45­9.53) µmol H2O2 Eq/L] (P < 0.001). TAC was higher in patients with non-CF BE [1.07 (1.0­1.07) mmol Trolox Eq/L] than in the healthy controls [0.87 (0.77­0.98) mmol Trolox Eq/L] (P < 0.001). In addition, serum PON1 levels were significantly higher in the patients [106.5 (42.5­154.2) U/L] than in the controls [47.7 (27.5­82.1) U/L] (P < 0.001). The patients with low FEV1 had decreased TAC when compared to those who had normal FEV1 in non-CF BE. Conclusion: The present study demonstrated that compared with the control group the children with non-CF BE had elevated oxidative status, antioxidant defenses parameters, and PON1 values.

Low DHEAS Concentration in a Girl Presenting with Short Stature and Premature Pubarche: A Novel PAPSS2 Gene Mutation.

OBJECTIVE: Dehydroepiandrosterone (DHEA) sulfotransferase (SULT2A1) converts DHEA to DHEA sulfate (DHEAS) which prevents bioactive androgen excess. This enzymatic reaction requires PAPS (3'-phospho-adenosine-5'-phosphosulfate) biosynthesis mediated by PAPS synthase 2 (PAPSS2). Here, we report a patient presenting with short stature and premature pubarche due to a novel homozygous mutation in the PAPPS2 gene. CASE REPORT: A 7.5-year-old girl was referred for short stature. She was born at term with a birth weight of 2,850 g and her parents were first cousins. At presentation, her height was 113.0 cm (-2.1 SDS) and weight was 28.3 kg (+0.9 SDS), her arm span was 115.0 cm, and upper to lower segment ratio was 1.2. Her pubic hair and breast development were at Tanner stage III and I, respectively. Radiographs revealed mild lumbar scoliosis and platyspondyly and irregular vertebral endplates in the thoracolumbar region. Her serum DHEAS was low (39 ng/mL). The plasma DHEAS/DHEA ratio was significantly decreased on 2 separate measurements (4.4 and 19.8; normal range 31-345). PAPSS2 gene analysis identified a homozygous p.L440Wfs*12 (c.1318_1330 delCTACTACACCCTC) variant. This is the first report of a large deletion leading to a frameshift effect in the PAPSS2 gene and a truncated PAPSS2 protein. CONCLUSION: We describe the third case with PAPSS2 deficiency presenting with premature pubarche, and the first large deletion in the PAPSS2 gene. Although PAPSS2 deficiency is a rare cause of premature pubarche and adrenal androgen excess, it should be considered, especially in cases with disproportionate short stature and clinical hyperandrogenism associated with low plasma DHEAS concentration.

Evaluation of growth and puberty in a child with a novel TBX19 gene mutation and review of the literature.

BACKGROUND: Biallelic mutations in the TBX19 gene cause severe early-onset adrenal failure due to isolated ACTH deficiency (IAD). This rare disease is characterized by low plasma ACTH and cortisol levels, with normal secretion of other pituitary hormones. Herein, we report a patient with IAD due to a novel TBX19 gene mutation, who is also of tall stature. CASE REPORT: A 48/12-year-old girl was presented with loss of consciousness due to hypoglycemia. The patient was born at term with a birth weight of 3800 g. Her parents were first-degree cousins. She had a history of several hospitalizations for recurrent seizures, abdominal pain, and vomiting. At presentation, her weight and height were + 1.8 and + 2.2 SDS, respectively. Serum glucose was 25 mg/dl (1.4 mmol/L), with normal sodium, potassium, and insulin concentrations. The child was hypocortisolemic (0.1 µg/dl), and ACTH levels were extremely low (< 5.0 pg/ml). A diagnosis of IAD was made and hydrocortisone treatment was started. Hypoglycemic episodes, seizures, and recurrent gastrointestinal complaints disappeared after hydrocortisone replacement. Magnetic resonance imaging of the pituitary was normal. Whole exome sequencing revealed a novel homozygous c.302G > A (W101*) mutation in the TBX19 gene. CONCLUSION: We report a new mutation in the TBX19 gene in a patient with isolated ACTH deficiency. While overgrowth is a known feature of some types of adrenal insufficiencies, including MC2R gene defects and POMC deficiency, it may be a novel feature for TPIT deficiency, as in our patient.