Severe Early-Onset Obesity and Diabetic Ketoacidosis due to a Novel Homozygous c.169C>T p.Arg57* Variant in CEP19 Gene

Introduction

Early-onset severe obesity is usually the result of an underlying genetic disorder, and several genes have recently been shown to cause syndromic and nonsyndromic forms of obesity. The "centrosomal protein 19 (CEP19)" gene encodes for a centrosomal and ciliary protein. Homozygous variants in the CEP19 gene are extremely rare causes of early-onset severe monogenic obesity. Herein, we present a Turkish family with early-onset severe obesity with variable features.

Methods

Sanger sequencing and whole-exome sequencing were performed to identify the genetic etiology in the family.

Results

The index case was a 12-year-old female who presented with severe obesity (BMI of 62.7 kg/m2), metabolic syndrome, and diabetic ketoacidosis. Her nonidentical twin female siblings also had early-onset severe obesity, metabolic syndrome, and diabetes. In addition, one of the affected siblings had situs inversus abdominalis, polysplenia, lumbar vertebral fusion, and abnormal lateralization. A novel homozygous nonsense (c.169C>T, p. Arg57*) pathogenic variant was detected in exon 3 of the CEP19 gene in all affected members of the family. One unaffected sister and unaffected parents were heterozygous for the variant. This variant is predicted to cause a stop codon at amino acid sequence 57, leading to a truncated CEP19 protein.

Discussion/Conclusion

Our study expands the phenotypical manifestations and variation database of CEP19 variants. The findings in one of our patients reaffirm its role in the assembly and function of both motile and immotile cilia.

Serum kisspeptin, neurokinin B and inhibin B levels can be used as alternative parameters to distinguish idiopathic CPP from premature thelarche in the early stages of puberty

OBJECTIVE

There is controversial results about serum kisspeptin, neurokinin-B (NKB), anti-Müllerian hormone (AMH) and inhibin B (INHB) levels in girls with central precocious puberty (CPP). Aim of this study is to evaluate serum levels of these four peptides in patients presented with early pubertal signs, and to evaluate their diagnostic validity in the diagnosis of CPP.

DESIGN

Cross-sectional study.

PATIENTS

Study included 99 girls (51 CPP, 48 premature thelarche [PT]) whose breast development started before 8 years and 42 age-matched healthy prepubertal girls. Clinical findings, antropometric measurements, laboratory and radiological findings were recorded. Gonadotropin-releasing hormone (GnRH) stimulation test was performed in all cases with early breast development.

MEASUREMENTS

Kisspeptin, NKB, INHB and AMH levels were measured in fasting serum samples using enzyme-linked immunosorbent assay method.

RESULTS

There was no statistically significant difference between mean ages of girls with CPP (7.1 ± 1.2 years), PT (7.2 ± 1.3 years) and prepubertal controls (7.0 ± 1.0 years). Serum kisspeptin, NKB and INHB levels were higher in CPP group compared to PT and control groups, while serum AMH level was lower in CPP group. Serum kisspeptin, NKB, and INHB were all positively correlated with bone age (BA) advancement, and peak luteinizing hormone in GnRH test. Multiple stepwise regression analysis revealed that the most important factors used to differentiate CPP from PT were advanced BA, serum kisspeptin, NKB and INHB levels (AUC: 0.819, p < .001).

CONCLUSIONS

We, first showed in the same patients' group that serum kisspeptin, NKB and INHB were higher in patients with CPP and can be used as alternative parameters to distinguish CPP from PT.

Managing Severe Hypoglycaemia in Patients with Diabetes: Current Challenges and Emerging Therapies

Hypoglycaemia is common in patients with diabetes mellitus and is a limiting factor for achieving adequate glycaemic control. In the vast majority of cases, hypoglycaemia develops due to the imbalance between food intake and insulin injections. As recurrent hypoglycaemia leads to significant morbidity and mortality, the recognition and immediate treatment of hypoglycaemia in diabetic patients is thus important. In the last 20 years, the introduction of improved insulin analogues, insulin pump therapy, continuous glucose monitoring (CGM), and sensor-augmented pump therapy have all made significant improvements in helping to reduce and prevent hypoglycaemia. In terms of treatment, the American Diabetes Association recommends oral glucose as the first-line treatment option for all conscious patients with hypoglycaemia. The second line of treatment (or first line in unconscious patients) is the use of glucagon. Novel formulations of glucagon include the nasal form, the Gvoke HypoPen which is a ready-to-deliver auto-injector packaged formulation and finally a glucagon analogue, Dasiglucagon. The Dasiglucagon formulation has recently been approved for the treatment of severe hypoglycaemia. It is a ready-to-use, similar to endogenous glucagon and its potency is also the same as native glucagon. It does not require reconstitution before injection and therefore ensures better compliance. Thus, significant improvements including development of newer insulin analogues, insulin pump therapy, continuous glucose monitoring (CGM), sensor-augmented pump therapy and novel formulations of glucagon have all contributed to reducing and preventing hypoglycaemia in diabetic individuals. However, considerable challenges remain as not all patients have access to diabetes technologies and to the newer glucagon formulations to help reduce and prevent hypoglycaemia.

Incidence and Risk Factors of Hyperglycemia in Severe Multisystem Inflammatory Syndrome in Children: A Retrospective Case-Control Study

Objective Multisystem inflammatory syndrome in children (MIS-C) patients might be at risk for hyperglycemia and associated complications. Herein, we aimed to determine the incidence of hyperglycemia, understanding the underlying risk factors in MIS-C patients.

Methods All MIS-C patients were retrospectively evaluated and compared according to the presence of hyperglycemia and the need of insulin. Inflammatory markers and body mass index Z-scores were also compared.

Results The median age of the patients with hyperglycemia was higher than those without (p = 0.001). Disease severity scores of patients with hyperglycemia were higher. Procalcitonin levels of patients with hyperglycemia were higher, while ferritin, CRP, and interleukin-6 levels were not. BMIs of patients with hyperglycemia were higher (p = 0.01) but BMI Z-scores were similar (p = 0.055). There was a positive correlation between BMIs and CRP (r: 0.31, p = 0.015). There was a positive correlation between procalcitonin (r: 0.431, p = 0.001) and CRP (r: 0.279, p = 0.029) and maximum PG.

Conclusion Hyperglycemia is a common feature of MIS-C patients and is associated with the severity of the inflammation. As a novel finding, high CRP and procalcitonin should be considered as predictive markers for impaired glucose homeostasis in MIS-C patients.

TWO OPPOSITE PHENOTYPES OF GLUCOSE DISORDERS IN A FAMILY WITH HETEROZYGOUS P.SER453LEU (C.1358C> T) MUTATION IN THE GLUCOKINASE (GCK) GENE: MATURITY ONSET DIABETES IN YOUNG AND INSULINOMA

Background

Heterozygous gain-of-function mutations in the glucokinase (GCK) gene cause hyperinsulinaemic hypoglycaemia (GCK-HI), while loss-of-function mutations lead to a monogenic type of diabetes (GCK-MODY). We, herein, report a heterozygous GCK gene mutation in a large family with GCK-MODY and insulinoma in one individual from the same family.

Patients and methods

The proband, an 11-year-old male, was referred for asymptomatic mild hyperglycemia (fasting glucose:121 mg/dL) and HbA1c of 6.1%. Segregation analysis of the family revealed multiplex members with asymptomatic fasting hyperglycaemia or non-insulin-dependent diabetes and 33-year-old maternal uncle of the proband case had a history of distal pancreatectomy due to the diagnosis of insulinoma. His preoperative investigations were revealed fasting glucose of 31 mg/dL, insulin: 7µU/mL, C-peptide: 2.6 mg/dL, and a low HbA1c(4.0%) which was suggestive for recurring hypoglycaemia episodes. Post-pancreatectomy he developed mild fasting hyperglycemia (115-136 mg/dL).

Results

Genetic analysis revealed heterozygous p.Ser453Leu(c.1358C> T) mutation in the GCK gene in the proband. In segregation analysis, the identical heterozygous p.Ser453Leu(c.1358C> T) GCK gene mutation was detected in all of the other affected family members for whom a DNA analysis was applicable. The maternal uncle was first diagnosed with insulinoma and underwent a pancreatectomy. He also had an identical mutation in a heterozygous state.

Conclusion

We, to the best of our knowledge, firstly identified these two entirely distinct phenotypes of glucose metabolism, GCK-MODY and GCK-HI, due to an identical heterozygous p.Ser453Leu (c.1358C> T) mutation in the GCK. Further studies required to elucidate this new phenomenon and understanding the genotype-phenotype relationship of GCK gene mutations.

The effects of the covid-19 pandemic on puberty: a cross-sectional, multicenter study from Turkey

BACKGROUNDS

During the Coronavirus-19 disease (Covid-19) pandemic it was observed that the number of girls presenting with early puberty had increased. The aim of this study was to carry out a retrospective evaluation of the characteristics of girls who had been referred for evaluation of precocious puberty in five different pediatric endocrinology units, before and during the pandemic.

METHODS

The study participants comprised 359 girls who were assigned into 2 groups a pre-pandemic group (n:214) and a pandemic group (n:145). Those participants (n:99) who had medical records in the follow-up period were classified into 3 subgroups according to the time of presentation and follow-up visits (group-1: first admission and follow-up visit before the pandemic, group-2: first admission before the pandemic, the follow-up visit during the pandemic, group-3: first admission and follow-up visit during the pandemic).

RESULTS

The age at presentation and age at pubertal onset were both significantly lower in the pandemic group than those in the pre-pandemic group(8.1 vs 8.6, p: < 0.001,7.7 vs 7.9,p:0.013, respectively). There was no significant difference between the body mass index standard deviation scores (BMI-SDS) values of the groups (0.57 vs 0.51, p:0.430). The initiation rate of pubertal suppression therapy at the time of presentation was significantly higher in the pandemic group compared to that of the pre-pandemic group (7.7%vs 27.5%), and in groups-2 & 3 compared to group-1, during follow-up (20%&44%vs 8%).

CONCLUSION

Our research showed that the onset of puberty occurred earlier in the pandemic period compared to the previous year, and the need for pubertal suppression therapy increased during the pandemic.

Revisiting the Annual Incidence of Type 1 Diabetes Mellitus in Children from the Southeastern Anatolian Region of Turkey: A Regional Report

OBJECTIVE

The incidence of type 1 diabetes mellitus (T1D) in children has an increasing trend globally, with a variable rate depending on region and ethnicity. Our group first reported T1D incidence in Diyarbakır in 2011. The aim of this study was to evaluate the current incidence rate of pediatric T1D in Diyarbakır, and compare the incidence, and clinical and presenting characteristics of more recent cases with those reported in our first report.

METHODS

Hospital records of patients diagnosed with T1D in Diyarbakır city between 1^st January 2020 and 31^st December 2020 and aged under 18 years old were retrieved, and their medical data was extracted. Demographic population data were obtained from address-based census records of the Turkish Statistical Institution (TSI).

RESULTS

Fifty-seven children and adolescents were diagnosed with T1D. Of those, 34 were female (59.6%), indicating a male/female ratio of 1.47. The mean age at diagnosis was 9.5±3.9 years (0.8-17.9). TSI data indicated a population count of 709,803 for the 0-18 years age group. Thus the T1D incidence was 8.03/10⁵ in the 0-18 age group and was higher in the 0-14 age group at 9.14/10⁵. The cumulative increase in the incidence of T1D in the 0-14 age group was 26.9% suggesting an increasing rate of 2.7% per year. The frequency of presentation with diabetic ketoacidosis was 64.9%.

CONCLUSION

The annual incidence of pediatric T1D in Diyarbakır city increased from 7.2/10⁵ to 9.14/10⁵ within the last decade. The rate of annual increase was 2.7% in the 0-14 age group comparing this study with our earlier report, with a predominance in male subjects and a shift of peak incidence from the 5-9 year age group in the first study to the 10-14 year age group in this one.

Clinical and genetic heterogeneity of HNF4A/HNF1A mutations in a multicentre paediatric cohort with hyperinsulinaemic hypoglycaemia

OBJECTIVE

The phenotype mediated by HNF4A/HNF1A mutations is variable and includes diazoxide-responsive hyperinsulinaemic hypoglycaemia (HH) and maturity-onset diabetes of the young (MODY).

DESIGN

We characterised an international multicentre paediatric cohort of patients with HNF4Aor HNF1Amutations presenting with HH over a 25-year period (1995-2020).

METHODS

Clinical and genetic analysis data from five centres were obtained. Diazoxide responsiveness was defined as the ability to maintain normoglycaemia without intravenous glucose. Macrosomia was defined as a birth weight ≥90th centile. SPSS v.27.1 was used for data analysis.

RESULTS

A total of 34 patients (70.6% female, n = 24) with a mean age of 7.1 years (s.d. 6.4) were included. A total of 21 different heterozygous HNF4Amutations were identified in 29 patients (four novels). Four different previously described heterozygous HNF1A mutations were detected in five patients. Most (97.1%, n = 33) developed hypoglycaemia by day 2 of life. The mean birth weight was 3.8 kg (s.d. 0.8), with most infants macrosomic (n = 21, 61.8%). Diazoxide was commenced in 28 patients (82.3%); all responded. HH resolved in 20 patients (58.8%) following a median of 0.9 years (interquartile range (IQR): 0.2-6.8). Nine patients (n = 9, 26.5%) had developmental delay. Two patients developed Fanconi syndrome (p.Arg63Trp, HNF4A) and four had other renal or hepatic findings. Five (14.7%) developed MODY at a median of 11.0 years (IQR: 9.0-13.9). Of patients with inherited mutations (n = 25, 73.5%), a family history of diabetes was present in 22 (88.0%).

CONCLUSIONS

We build on the knowledge of the natural history and pancreatic and extra-pancreatic phenotypes of HNF4A/HNF1Amutations and illustrate the heterogeneity of this condition.

Systematic genetic testing for recessively inherited monogenic diabetes: a cross-sectional study in paediatric diabetes clinics

AIMS/HYPOTHESIS

Current clinical guidelines for childhood-onset monogenic diabetes outside infancy are mainly focused on identifying and testing for dominantly inherited, predominantly MODY genes. There are no systematic studies of the recessively inherited causes of monogenic diabetes that are likely to be more common in populations with high rates of consanguinity. We aimed to determine the contribution of recessive causes of monogenic diabetes in paediatric diabetes clinics and to identify clinical criteria by which to select individuals for recessive monogenic diabetes testing.

METHODS

We conducted a cross-sectional study of 1093 children from seven paediatric diabetes clinics across Turkey (a population with high rates of consanguinity). We undertook genetic testing of 50 known dominant and recessive causes of monogenic diabetes for 236 children at low risk of type 1 diabetes. As a comparison, we used monogenic diabetes cases from UK paediatric diabetes clinics (a population with low rates of consanguinity).

RESULTS

Thirty-four children in the Turkish cohort had monogenic diabetes, equating to a minimal prevalence of 3.1%, similar to that in the UK cohort (p = 0.40). Forty-one per cent (14/34) had autosomal recessive causes in contrast to 1.6% (2/122) in the UK monogenic diabetes cohort (p < 0.0001). All conventional criteria for identifying monogenic diabetes (parental diabetes, not requiring insulin treatment, HbA_1c ≤ 58 mmol/mol [≤7.5%] and a composite clinical probability of MODY >10%) assisted the identification of the dominant (all p ≤ 0.0003) but not recessive cases (all p ≥ 0.2) in Turkey. The presence of certain non-autoimmune extra-pancreatic features greatly assisted the identification of recessive (p < 0.0001, OR 66.9) but not dominant cases.

CONCLUSIONS/INTERPRETATION

Recessively inherited mutations are a common cause of monogenic diabetes in populations with high rates of consanguinity. Present MODY-focused genetic testing strategies do not identify affected individuals. To detect all cases of monogenic paediatric diabetes, it is crucial that recessive genes are included in genetic panels and that children are selected for testing if they have certain non-autoimmune extra-pancreatic features in addition to current criteria.

NUTRITIONAL HABITS, COMPLIANCE WITH HEALTHY DIET AND INSULIN THERAPY, DEPRESSION AND FAMILY FUNCTIONALITY IN CHILDREN WITH TYPE 1 DIABETES MELLITUS DURING THE COVID-19 PANDEMIC PERIOD

CONTEXT

The relationship between life changes and glycemic control in children with type 1 diabetes during the pandemic period was examined.

OBJECTIVE

We aimed to investigate the effect of the pandemic period on 66 children (aged 5-18 years) with type 1 diabetes using scales evaluating family functionality, nutritional habits, adherence to treatment and depression status.

DESIGN

It is a cross-sectional clinical and laboratory study using certain scales for its descriptive features.

SUBJECTS AND METHODS

Demographic characteristics, anthropometric measurements, laboratory investigations were evaluated. Family functionality of the patients were evaluated with Smilkstein's family APGAR scale, motivation and knowledge levels were evaluated with the 6-item Morisky medication adherence scale (MMAS-6), nutritional habits were evaluated with the Mediterranean diet quality index (KIDMED), and depression status was evaluated with the children depression inventory (CDI).

RESULTS

The mean HbA_1c level increased significantly in the first year of the pandemic compared to the onset of the pandemic period (8.5% vs. 8.9%, p: 0.003). In the responses to these scales, children with diabetes have high family functionality (89.4%), high motivation (90.9%) and high knowledge level about adherence to treatment (97%). Furthermore, healthy eating habits (high KIDMED index scores 92.4%), and low degree of depression score (95.5%) have been observed. We detected a statistically significant positive correlation between HbA_1c and CDI scores (r: 0.27; p: 0.02), and a negative correlation between HbA_1c and MMAS-6 motivation score (r: -0.30; p: 0.01).

CONCLUSIONS

In this study, the effect of motivation and mood changes on glycemic control was more clearly demonstrated.

A rare and preventable aetiology of neurodevelopmental delay and epilepsy: familial glucocorticoid deficiency

OBJECTIVES

Familial glucocorticoid deficiency (FGD) is a rare autosomal recessive disorder characterised by isolated glucocorticoid deficiency. Melanocortin receptor 2 (MC2R) mediates the functions of adrenocorticotropic hormone (ACTH) in the adrenal cortex. MC2R accessory protein (MRAP) is a transmembrane protein involved in the trafficking of MC2R to the cell surface. Mutations in MC2R and MRAP genes cause FGD type 1 and 2. In the present case series, we evaluate the clinical characteristics and long-term follow-up of six cases with FGD due to mutations in MC2R and MRAP.

CASE PRESENTATION

Data of six cases with FGD (five with mutations in MC2R and one with a mutation in MRAP) who were being followed at our paediatric endocrine centre was evaluated. Diagnosis of FGD was considered in case of elevated ACTH and inappropriately low cortisol level, and exclusion of other aetiologies. The main presenting complaints were hyperpigmentation and hypoglycaemic convulsion in all cases. During a follow-up period of 26-115 months, one patient with homozygous 560delT mutation in MC2R, one female with G226R mutation in MC2R and one female with IVS3ds+1delG mutation in MRAP had a neurodevelopmental delay (NDD), while the other three patients had normal neurodevelopment.

CONCLUSIONS

FGD patients due to MC2R and MRAP mutations with early diagnosis and compliance to the hydrocortisone therapy had normal neurodevelopment, while delay in diagnosis and poor compliance was associated with severe hypoglycaemic convulsions and subsequent complications NDD.

Clinical and Hormonal Profiles Correlate With Molecular Characteristics in Patients With 11β-Hydroxylase Deficiency

BACKGROUND

Given the rarity of 11β-hydroxylase deficiency (11βOHD), there is a paucity of data about the differences in clinical and biochemical characteristics of classic (C-11βOHD) and nonclassic 11βOHD (NC-11βOHD).

OBJECTIVE

To characterize a multicenter pediatric cohort with 11βOHD.

METHOD

The clinical and biochemical characteristics were retrospectively retrieved. CYP11B1 gene sequencing was performed. Seventeen plasma steroids were quantified by liquid chromatography-mass spectrometry and compared to that of controls.

RESULTS

102 patients (C-11βOHD, n = 92; NC-11βOHD, n = 10) from 76 families (46,XX; n = 53) had biallelic CYP11B1 mutations (novel 9 out of 30). Five 46,XX patients (10%) were raised as males. Nineteen patients (19%) had initially been misdiagnosed with 21-hydroxylase deficiency. Female adult height was 152 cm [-1.85 SD score (SDS)] and male 160.4 cm (-2.56 SDS).None of the NC-11βOHD girls had ambiguous genitalia (C-11βOHD 100%), and none of the NC-11βOHD patients were hypertensive (C-11βOHD 50%). Compared to NC-11βOHD, C-11βOHD patients were diagnosed earlier (1.33 vs 6.9 years; P < 0.0001), had higher bone age-to-chronological age (P = 0.04) and lower adult height (-2.46 vs -1.32 SDS; P = 0.05). The concentrations of 11-oxygenated androgens and 21-deoxycortisol were low in all patients. The baseline ACTH and stimulated cortisol were normal in NC-11βOHD. Baseline cortisol; cortisone; 11-deoxycortisol; 11-deoxycorticosterone and corticosterone concentrations; and 11-deoxycortisol/cortisol, 11-deoxycorticosterone/cortisol, and androstenedione/cortisol ratios were higher in C-11βOHD than NC-11βOHD patients (P < 0.05). The 11-deoxycortisol/cortisol ratio >2.2, <1.5, and <0.1 had 100% specificity to segregate C-11βOHD, NC-11βOHD, and control groups.

CONCLUSION

NC-11βOHD can escape from clinical attention due to relatively mild clinical presentation. However, steroid profiles enable the diagnosis, differential diagnosis, and subtyping of 11βOHD.

Clinical characteristics and molecular genetic analysis of a cohort with idiopathic congenital hypogonadism

OBJECTIVES

Hypogonadism is defined as inadequate sex hormone production due to defects in the hypothalamic-pituitary-gonadal axis. In recent years, rare single gene defects have been identified in both hypergonadotropic hypogonadism (Hh), and hypogonadotropic hypogonadism (HH) cases with no chromosomal anomalies. The aim of the present study is to investigate the underlying molecular genetic etiology and the genotype-phenotype relationship of a series of patients with Hh and HH.

METHODS

In total, 27 HH and six Hh cases were evaluated. Clinical and laboratory features are extracted from patients' hospital files. Whole exome sequencing (WES) analysis was performed.

RESULTS

A total of 27 HH cases (15 female) (mean age: 15.8 ± 2.7 years) and six Hh patients (six females) (mean age: 14.9 ± 1.2 years) were included. In molecular genetic analysis, a pathogenic/likely pathogenic variant was identified in five (two patients from the same family) of 27 HH cases (two novel) and three of the six Hh. In HH group variants (pathogenic, likely pathogenic and variant of uncertain significance) were identified in KISS1R (n=2), PROK2 (n=1), FGFR1 (n=1), HS6ST1 (n=1), GNRH1 (n=1) genes. In the Hh group, splice-site mutations were detected in DCAF17 (n=1) and MCM9 (n=2) genes.

CONCLUSIONS

HH and Hh cases are genetically heterogeneous diseases due to oligogenic inheritance, incomplete penetrance, and variable expressivity. We found rare variants in CHH related genes in half of our HH cases, whereas they classified as pathogenic/likely pathogenic according to ACMG criteria in only about 15% of HH cases. Using advanced genetic analysis methods such as whole-genome sequencing and long-read sequencing may increase the mutation detection rate, which should always be associated with and expert genetic counseling to interpret the data.

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.

Neonatal diabetes due to homozygous INS gene promoter mutations: Highly variable phenotype, remission and early relapse during the first 3 years of life

Neonatal diabetes mellitus (NDM) is a rare form of monogenic diabetes presenting within the first 6 months of life. INS gene promoter mutations have been shown to cause both remitting/relapsing and permanent NDM. We, herein, present three interesting patients with INS gene promoter mutations. Two cousins with an identical homozygous c.-331C > G mutation presented with NDM. The first cousin had nonremitting diabetes and still requires multidose insulin injections at the current age of 6.1 years. However, the other cousin's diabetes remitted at the age of 9 months, and she is still in remission at the age of 3 years with no medication or dietary intervention required (latest HbA1c was 4.9%). The third patient had NDM also due to a homozygous INS promoter c.-331C>A mutation. Her diabetes remitted at the age of 2 months and relapsed at the age of 2.6 years with severe diabetic ketoacidosis (DKA). Distinct clinical phenotype and relapse with severe DKA in one of the three cases suggest that INS promotor mutations can cause a heterogeneous phenotype and even cases exhibiting remission can relapse unpredictably. Therefore, as the age of relapse is unpredictable, close follow-up and family education on diabetes symptoms are essential for cases with remitting/relapsing diabetes due to INS gene mutations.

Cystoscopy-Guided Laparoscopic Excision of Prostatic Utricle: Report of a Case

Prostatic utricle (PU) is incomplete regression of Müllerian duct and may cause recurrent urinary tract infections (UTIs), stone formation, postvoid dribbling, and recurrent epididymitis. Although surgical excision is recommended to avoid complications, surgical access to PU has been challenging. Cystoscopy-guided laparoscopic management of PU in a 3-year-old boy is reported to discuss use of other endoscopic aids in the surgical treatment of PU. He was admitted with disordered sexual development with karyotype of 47,XYY/46,XY and has been experiencing recurrent UTIs. Voiding cystourethrogram (VCU) demonstrated large PU (IKOMA II). Cystoscopy was performed confirming PU and the cystoscope was left in situ to aid laparoscopic exploration after bladder was emptied. A 5-mm umbilical port and two 5-mm ports in both lower quadrants were inserted. The peritoneum was dissected behind bladder. The cystoscope in PU was used as guidance in identification and dissection of PU. The vas deferens was identified and could be secured. The neck of PU was ligated with surgiloop. PU was retrieved from umbilical port. Postoperative VCU revealed normal posterior urethra. He has been free of UTIs for the last 6 months. Laparoscopy is safe and feasible alternative in surgical management of PU, by providing good visual exposure, easy dissection in deep pelvis, and improved cosmesis. The cystoscopic guidance is an important aid in identification and dissection of PU.

A novel diagnostic tool for the evaluation of hypothalamic-pituitary region and diagnosis of growth hormone deficiency: pons ratio

Backgrounds Limitations in the evaluation of the pituitary size and changes according to pubertal status make its validity questionable. Recently, in a small-scale study, pons ratio (PR) has been suggested as a more sensitive tool for diagnosis and etiological evaluation of growth hormone deficiency (GHD). The aim of the study is to evaluate the diagnostic value of PR in the diagnosis of GHD. Methods We retrospectively evaluated the pituitary magnetic resonance imaging (MRI) of 133 patients with a diagnosis of GHD. Primary axis (PA) was assigned as a line crossing the mid-sagittal dorsum sella and fourth ventricle. PR was defined as the pons height above the PA divided by total pons height. The PR of patients with GHD was compared to subjects without GHD. Results Study included 133 patients with GHD and 47 controls. In total, 121 (91%) patients had isolated GHD and 12 (9%) patients had multiple pituitary hormone deficiency. The PR of the patient group (mean: 0.32 ± 0.89; range: 0.14-0.63) was significantly higher than controls (mean: 0.26 ± 0.067; range 0.19-0.44) (p: 0.000). The optimal cut-off value of PR for GHD diagnosis was 0.27 (sensitivity 71% specificity 56%). There was a negative correlation between anterior pituitary height (APH)-SDS and PR (p: 0.002; r: -0.27). APH was increased, but PR remained unchanged in pubertal patients (p: 0.089). Conclusions PR measurement is a noninvasive, practical method with a cost-benefit clinical value. As it is not affected by pubertal status, PR is potentially a more sensitive tool for evaluation of pituitary gland in GHD patients compared to APH.

Systemic Pseudohypoaldosteronism Type 1 due to 3 Novel Mutations in SCNN1Aand SCNN1BGenes

OBJECTIVE

The systemic form of pseudohypoaldosteronism type 1 (PHA1) is an autosomal recessive disorder characterized by defective sodium transport in multi-organ systems. Mutations in the genes encoding the amiloride-sensitive epithelial sodium channel, ENaC, account for genetic causes of systemic PHA1. We describe systemic PHA1 due to 4 novel variants detected in SCNN1A and SCNN1B in 3 cases from 3 unrelated consanguineous families.

PATIENTS AND METHODS

We evaluated the clinical presentations, biochemical and hormonal characteristics, and molecular genetic analysis results of 3 patients from 3 unrelated consanguineous families and parents from whom samples were available.

RESULTS

The ages at presentation were postnatal days 9, 10, and 5. The main presentation symptoms were vomiting, poor feeding, weakness, weight loss, and skin rash. All patients exhibited laboratory characteristics including severe hyponatremia, hyperkalemia, metabolic acidosis, elevated plasma renin, elevated aldosterone, and positive sweat tests, suggesting a diagnosis of systemic PHA1. Molecular genetic analysis revealed 2 novel pathogenic variants [c.87C>A(p.Tyr29*)/IVS9 + 1G>A (c.1346 + 1G>A)] in SCNN1Bin case 1, a novel homozygous pathogenic variant [p.His69Arg(c.206A>G] in SCNN1Ain case 2, and a homozygous one-base duplication, p.A200Gfs*6 (c.598dupG), in SCNN1A in case 3.

CONCLUSION

PHA1 should be considered at differential diagnosis in patients presenting with hyponatremia, hyperkalemia, and metabolic acidosis. The cases in this report involving 4 novel variants will add valuable insights into the phenotype-genotype relationship and will expand the mutation database.

A Distinct Clinical Phenotype in Two Siblings with X-linked Adrenoleukodystrophy

OBJECTIVES

X-linked adrenoleukodystrophy(X-ALD) is a rare X-linked recessive metabolic disorder. The mutations in the ATP Binding Cassette Subfamily D Member 1 (ABCD1) gene account for the underlying molecular mechanism. Herein, we present two siblings with X-ALD due to a missense, presumably identical, ABCD1 mutation, who had extremely distinct clinical phenotypes.

MATERIAL AND METHODS

Patient 1 (6y/o) was admitted with primary adrenal insufficiency (PAI). His VLCFA analysis and cranial MRI suggested the diagnosis of X-ALD with no cranial involvement. Although the PAI was successfully managed using hydrocortisone replacement therapy, during follow-up he was admitted with the complaints of perception impairment, seizures, loss of vision and deafness suggesting cranial involvement which was not able to be recovered despite intensive supportive therapies; in the end patient died. Patient 2 (21y/o) had mild symptoms of PAI with no organ manifestation. He was undertaken to a molecular genetics analysis for ABCD1 gene due to history of his brother. His VLCFA analysis revealed mildly elevated C26, C22 and C26/C22 ratio suggesting ALD diagnosis. However, his cranial imaging and other results were within normal limits.

CONCLUSION

Two siblings with X-ALD due to presumably an identical, missense ABCD1 mutation and distinct clinical phenotype have confirmed the lack of phenotype-genotype correlation and proved the essential role of molecular genetics analysis in the early diagnosis. It is crucial to follow up for the development of cranial involvement and decide a bone marrow transplantation which is the only option that can prevent the progression of the disease, thus extend the lifespan.

Permanent neonatal diabetes mellitus and neurological abnormalities due to a novel homozygous missense mutation in NEUROD1

The basic helix-loop-helix (bHLH) transcription factor, neuronal differentiation 1 (NEUROD1) (also known as BETA2) is involved in the development of neural elements and endocrine pancreas. Less than 10 reports of adult-onset non-insulin-dependent diabetes mellitus (NIDDM) due to heterozygous NEUROD1 mutations and 2 cases with permanent neonatal diabetes mellitus (PNDM) and neurological abnormalities due to homozygous NEUROD1 mutations have been published. A 13 year-old female was referred to endocrine department due to hyperglycemia. She was on insulin therapy following a diagnosis of neonatal diabetes mellitus (NDM) at the age of 9-weeks but missed regular follow-up. Parents are second cousin. There was a significant family history of adult onset NIDDM including patient's father. Auxological measurements were within normal ranges. On laboratory examination blood glucose was 33.2 mmol/L with undetectable c-peptide and glycosylated hemoglobin level of 8.9% (73.8 mmol/mol). She had developed difficulty in walking at the age of 4 years which had worsened over time. On further evaluation, a diagnosis of visual impairment, mental retardation, ataxic gait, retinitis pigmentosa and sensory-neural deafness were considered. Cranial magnetic resonance imaging revealed cerebellar hypoplasia. Molecular genetic analysis using targeted next generation sequencing detected a novel homozygous missense mutation, p.Ile150Asn(c.449T>A), in NEUROD1. Both parents and 2 unaffected siblings were heterozygous for the mutation. We report the third case of PNDM with neurological abnormalities caused by homozygous NEUROD1 mutation, the first caused by a missense mutation. Heterozygous carriers of the p.Ile150Asn mutation were either unaffected or diagnosed with diabetes in adulthood. It is currently unclear whether the NEUROD1 heterozygous mutation has contributed to diabetes development in these individuals.

Hyperinsulinaemic hypoglycaemia in children and adults

Pancreatic β cells are functionally programmed to release insulin in response to changes in plasma glucose concentration. Insulin secretion is precisely regulated so that, under normal physiological conditions, fasting plasma glucose concentrations are kept within a narrow range of 3·5-5·5 mmol/L. In hyperinsulinaemic hypoglycaemia, insulin secretion becomes dysregulated (ie, uncoupled from glucose metabolism) so that insulin secretion persists in the presence of low plasma glucose concentrations. Hyperinsulinaemic hypoglycaemia is the most common cause of severe and persistent hypoglycaemia in neonates and children. At a molecular level, mutations in nine different genes can lead to the dysregulation of insulin secretion and cause this disorder. In adults, hyperinsulinaemic hypoglycaemia accounts for 0·5-5·0% of cases of hypoglycaemia and can be due either to β-cell tumours (insulinomas) or β-cell hyperplasia. Rapid diagnosis and prompt management of hyperinsulinaemic hypoglycaemia is essential to avoid hypoglycaemic brain injury, especially in the vulnerable neonatal and childhood periods. Advances in the field of hyperinsulinaemic hypoglycaemia include use of rapid molecular genetic testing for the disease, application of novel imaging techniques (6-[fluoride-18]fluoro-levodopa [¹⁸F-DOPA] PET-CT and glucagon-like peptide 1 (GLP-1) receptor imaging), and development of novel medical treatments (eg, long-acting octreotide formulations, mTOR inhibitors, and GLP-1 receptor antagonists) and surgical therapies (eg, laparoscopic surgery).

Diagnosis and treatment of hyperinsulinaemic hypoglycaemia and its implications for paediatric endocrinology

Glucose homeostasis requires appropriate and synchronous coordination of metabolic events and hormonal activities to keep plasma glucose concentrations in a narrow range of 3.5–5.5 mmol/L. Insulin, the only glucose lowering hormone secreted from pancreatic β-cells, plays the key role in glucose homeostasis. Insulin release from pancreatic β-cells is mainly regulated by intracellular ATP-generating metabolic pathways. Hyperinsulinaemic hypoglycaemia (HH), the most common cause of severe and persistent hypoglycaemia in neonates and children, is the inappropriate secretion of insulin which occurs despite low plasma glucose levels leading to severe and persistent hypoketotic hypoglycaemia. Mutations in 12 different key genes (ABCC8, KCNJ11, GLUD1, GCK, HADH, SLC16A1, UCP2, HNF4A, HNF1A, HK1, PGM1 and PMM2) constitute the underlying molecular mechanisms of congenital HH. Since insulin supressess ketogenesis, the alternative energy source to the brain, a prompt diagnosis and immediate management of HH is essential to avoid irreversible hypoglycaemic brain damage in children. Advances in molecular genetics, imaging methods (¹⁸F–DOPA PET-CT), medical therapy and surgical approach (laparoscopic and open pancreatectomy) have changed the management and improved the outcome of patients with HH. This up to date review article provides a background to the diagnosis, molecular genetics, recent advances and therapeutic options in the field of HH in children.

Severe hyponatremia and repeated intestinal resections for intestinal dysmotility mimicking congenital aganglionic megacolon due to delay in the diagnosis of congenital hypothyroidism

Congenital hypothyroidism (CH) may present with nonspecific signs and symptoms, though, majority of infants can be asymptomatic. Therefore, understimation and delay in diagnosis may result in severe complications. A 5-month-old female admitted to our clinic with the history of repeated surgical operations due to the diagnosis of congenital aganglionic megacolon. Investigations performed in our clinic revealed the diagnosis of congenital (primary) hypothyroidism due to thyroid agenesis. Histopathologic evaluation of previously resected colon sample revealed normal ganglionic cell included colon. During follow-up she developed severe hyponatremia with a plasma sodium level of 106 mEq/L. Eunatremia was maintained following achievement of euthyroid state. In conclusion, since presenting symptoms can be variable and nonspecific, hypotyhroidism should be kept in mind in the differential diagnosis of patients with persistent abdominal distention mimicking aganglionic megacolon and severe hyponatremia of unknown origin.

A novel ALMS1 homozygous mutation in two Turkish brothers with Alström syndrome

BACKGROUND

Alström syndrome (AS) is an extremely rare, autosomal recessive disorder characterised by multi-organ features that typically manifest within the first two decades of life. AS is caused by mutations in the Alström syndrome 1 (ALMS1) gene located at 2p13.1.

METHODS

In the current study, two brothers from a first-cousin consanguineous family presented with a complex phenotype and were suspected of having AS.

RESULTS

Both brothers were found to be homozygous for a novel nonsense c.7310C>A (p.S2437X) mutation in exon-8 of ALMS1 gene. The consanguineous parents were sequenced and both were heterozygous for the same mutation.

CONCLUSIONS

This particular mutation has never been reported before and confirmed the diagnosis of AS in the patients. Our work identifies a novel mutation in ALMS1 gene responsible for the complex phenotype of AS in these patients.

Rare Causes of Primary Adrenal Insufficiency: Genetic and Clinical Characterization of a Large Nationwide Cohort

CONTEXT

Primary adrenal insufficiency (PAI) is a life-threatening condition that is often due to monogenic causes in children. Although congenital adrenal hyperplasia occurs commonly, several other important molecular causes have been reported, often with overlapping clinical and biochemical features. The relative prevalence of these conditions is not known, but making a specific diagnosis can have important implications for management.

OBJECTIVE

The objective of the study was to investigate the clinical and molecular genetic characteristics of a nationwide cohort of children with PAI of unknown etiology.

DESIGN

A structured questionnaire was used to evaluate clinical, biochemical, and imaging data. Genetic analysis was performed using Haloplex capture and next-generation sequencing. Patients with congenital adrenal hyperplasia, adrenoleukodystrophy, autoimmune adrenal insufficiency, or obvious syndromic PAI were excluded.

SETTING

The study was conducted in 19 tertiary pediatric endocrinology clinics.

PATIENTS

Ninety-five children (48 females, aged 0-18 y, eight familial) with PAI of unknown etiology participated in the study.

RESULTS

A genetic diagnosis was obtained in 77 patients (81%). The range of etiologies was as follows: MC2R (n = 25), NR0B1 (n = 12), STAR (n = 11), CYP11A1 (n = 9), MRAP (n = 9), NNT (n = 7), ABCD1 (n = 2), NR5A1 (n = 1), and AAAS (n = 1). Recurrent mutations occurred in several genes, such as c.560delT in MC2R, p.R451W in CYP11A1, and c.IVS3ds+1delG in MRAP. Several important clinical and molecular insights emerged.

CONCLUSION

This is the largest nationwide study of the molecular genetics of childhood PAI undertaken. Achieving a molecular diagnosis in more than 80% of children has important translational impact for counseling families, presymptomatic diagnosis, personalized treatment (eg, mineralocorticoid replacement), predicting comorbidities (eg, neurological, puberty/fertility), and targeting clinical genetic testing in the future.

Clinical characteristics and molecular genetic analysis of 22 patients with neonatal diabetes from the South-Eastern region of Turkey: predominance of non-KATP channel mutations

BACKGROUND

Neonatal diabetes mellitus (NDM) is a rare form of monogenic diabetes and usually presents in the first 6 months of life. We aimed to describe the clinical characteristics and molecular genetics of a large Turkish cohort of NDM patients from a single centre and estimate an annual incidence rate of NDM in South-Eastern Anatolian region of Turkey.

DESIGN AND METHODS

NDM patients presenting to Diyarbakir Children State Hospital between 2010 and 2013, and patients under follow-up with presumed type 1 diabetes mellitus, with onset before 6 months of age were recruited. Molecular genetic analysis was performed.

RESULTS

Twenty-two patients (59% males) were diagnosed with NDM (TNDM-5; PNDM-17). Molecular genetic analysis identified a mutation in 20 (95%) patients who had undergone a mutation analysis. In transient neonatal diabetes (TNDM) patients, the genetic cause included chromosome 6q24 abnormalities (n=3), ABCC8 (n=1) and homozygous INS (n=1). In permanent neonatal diabetes (PNDM) patients, homozygous GCK (n=6), EIF2AK3 (n=3), PTF1A (n=3), and INS (n=1) and heterozygous KCNJ11 (n=2) mutations were identified. Pancreatic exocrine dysfunction was observed in patients with mutations in the distal PTF1A enhancer. Both patients with a KCNJ11 mutation responded to oral sulphonylurea. A variable phenotype was associated with the homozygous c.-331C>A INS mutation, which was identified in both a PNDM and TNDM patient. The annual incidence of PNDM in South-East Anatolian region of Turkey was one in 48 000 live births.

CONCLUSIONS

Homozygous mutations in GCK, EIF2AK3 and the distal enhancer region of PTF1A were the commonest causes of NDM in our cohort. The high rate of detection of a mutation likely reflects the contribution of new genetic techniques (targeted next-generation sequencing) and increased consanguinity within our cohort.

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.

Familial isolated growth hormone deficiency due to a novel homozygous missense mutation in the growth hormone releasing hormone receptor gene: clinical presentation with hypoglycemia

CONTEXT

Mutations in the growth hormone releasing hormone receptor (GHRHR) gene are a relatively rare cause of isolated growth hormone deficiency (IGHD).

OBJECTIVE

This study aimed to understand the biochemical basis of hypoglycemia in the index case and the molecular basis of severe short stature in a large consanguineous family with IGHD.

PATIENTS AND METHODS

The index case presented with a hypoglycemic convulsion, following which eight members in two related consanguineous Turkish families were identified with IGHD. Homozygosity mapping identified the homozygous regions shared only among the affected individuals. Sanger sequencing of GHRHR, which resided in the shared homozygous region, was performed. In silico analysis of the pathogenic GHRHR variant was performed.

RESULTS

The clinical presentation and hormonal analysis confirmed GH deficiency in all affected individuals. Magnetic resonance imaging scan of the pituitary gland showed anterior pituitary hypoplasia in five affected individuals in which the youngest was only 0.4 years old, but with normal pituitary size in three affected individuals. Homozygosity mapping showed two large homozygous regions on chromosome 7 shared only among affected individuals. Sanger sequencing of GHRHR gene present in one of these shared regions identified a novel homozygous missense mutation (p.C64G) segregating with the disease phenotype. In silico analysis predicted the mutation to be deleterious and disease causing.

CONCLUSIONS

We describe a large consanguineous Turkish kindred with IGHD due to a novel homozygous missense GHRHR mutation. This is the first description of presentation with hypoglycemia and the earliest reported occurrence of anterior pituitary hypoplasia in patients with GHRHR mutation.

Long-term follow-up of children with congenital hyperinsulinism on octreotide therapy

CONTEXT

Octreotide, a somatostatin analog, is commonly used in diazoxide unresponsive congenital hyperinsulinism (CHI) patients as a second-line therapy.

OBJECTIVE

The aims of this study were to evaluate the dose range, side effects, and long-term follow-up of octreotide therapy in a large cohort of CHI patients.

SETTING

The study was conducted at an international referral center for the management of CHI.

PATIENTS

Twenty-eight (17 males) diazoxide unresponsive CHI patients (15 biallelic and 10 monoallelic ATP sensitive potassium channel mutation) managed with daily multidose octreotide therapy between 2001 and 2013 participated in the study.

MAIN OUTCOME MEASURES

Regular follow-up of auxology, growth factors (serum IGF-1 and IGF binding protein 3 levels), thyroid functions, liver function tests, and hepatobiliary ultrasonography were measured.

RESULTS

The median age of CHI diagnosis was 1 week (range 1-80 wk). The mean (±SD) dose of octreotide required was 17.8 (±7.5) μg/kg · d (range 7.5-30 μg/kg · d). The mean (±SD) duration of follow-up on octreotide therapy was 52.4 (±33.8) months (range 6 mo to 9.5 y). Elevation of liver enzymes was the most prevalent side effect (n = 13; 46.4%), which resolved spontaneously. Gallbladder pathology was detected in nine patients (32%). Mean (±SD) duration of octreotide therapy before the development of gallbladder pathology was 4.3 (±4.6 mo), whereas 19 patients were free of gallstones after a follow-up of 53.6 ± 32.9 months on octreotide therapy. There was no relationship between the dose or the duration of octreotide therapy and development of gallbladder pathology or liver dysfunction.

CONCLUSIONS

Transient elevation of liver enzymes and asymptomatic gallbladder pathology were the most prevalent long-term side effects of octreotide therapy. There was no correlation between the dose or the duration of octreotide therapy and development of liver dysfunction and gallbladder pathology.

Phenotypic severity of homozygous GCK mutations causing neonatal or childhood-onset diabetes is primarily mediated through effects on protein stability

Mutations in glucokinase (GCK) cause a spectrum of glycemic disorders. Heterozygous loss-of-function mutations cause mild fasting hyperglycemia irrespective of mutation severity due to compensation from the unaffected allele. Conversely, homozygous loss-of-function mutations cause permanent neonatal diabetes requiring lifelong insulin treatment. This study aimed to determine the relationship between in vitro mutation severity and clinical phenotype in a large international case series of patients with homozygous GCK mutations. Clinical characteristics for 30 patients with diabetes due to homozygous GCK mutations (19 unique mutations, including 16 missense) were compiled and assigned a clinical severity grade (CSG) based on birth weight and age at diagnosis. The majority (28 of 30) of subjects were diagnosed before 9 months, with the remaining two at 9 and 15 years. These are the first two cases of a homozygous GCK mutation diagnosed outside infancy. Recombinant mutant GCK proteins were analyzed for kinetic and thermostability characteristics and assigned a relative activity index (RAI) or relative stability index (RSI) value. Six of 16 missense mutations exhibited severe kinetic defects (RAI ≤ 0.01). There was no correlation between CSG and RAI (r(2) = 0.05, P = 0.39), indicating that kinetics alone did not explain the phenotype. Eighty percent of the remaining mutations showed reduced thermostability, the exceptions being the two later-onset mutations which exhibited increased thermostability. Comparison of CSG with RSI detected a highly significant correlation (r(2) = 0.74, P = 0.002). We report the largest case series of homozygous GCK mutations to date and demonstrate that they can cause childhood-onset diabetes, with protein instability being the major determinant of mutation severity.

Clinical characteristics and phenotype-genotype analysis in Turkish patients with congenital hyperinsulinism; predominance of recessive KATP channel mutations

OBJECTIVE

Congenital hyperinsulinism (CHI) is the commonest cause of hyperinsulinaemic hypoglycaemia in the neonatal, infancy and childhood periods. Its clinical presentation, histology and underlying molecular biology are extremely heterogeneous. The aim of this study was to describe the clinical characteristics, analyse the genotype-phenotype correlations and describe the treatment outcome of Turkish CHI patients.

DESIGN AND METHODS

A total of 35 patients with CHI were retrospectively recruited from four large paediatric endocrine centres in Turkey. Detailed clinical, biochemical and genotype information was collected.

RESULTS

Diazoxide unresponsiveness was observed in nearly half of the patients (n=17; 48.5%). Among diazoxide-unresponsive patients, mutations in ABCC8/KCNJ11 were identified in 16 (94%) patients. Among diazoxide-responsive patients (n=18), mutations were identified in two patients (11%). Genotype-phenotype correlation revealed that mutations in ABCC8/KCNJ11 were associated with an increased birth weight and early age of presentation. Five patients had p.L1171fs (c.3512del) ABCC8 mutations, suggestive of a founder effect. The rate of detection of a pathogenic mutation was higher in consanguineous families compared with non-consanguineous families (87.5 vs 21%; P<0.0001).Among the diazoxide-unresponsive group, ten patients were medically managed with octreotide therapy and carbohydrate-rich feeds and six patients underwent subtotal pancreatectomy. There was a high incidence of developmental delay and cerebral palsy among diazoxide-unresponsive patients.

CONCLUSIONS

This is the largest study to report genotype-phenotype correlations among Turkish patients with CHI. Mutations in ABCC8 and KCNJ11 are the commonest causes of CHI in Turkish patients (48.6%). There is a higher likelihood of genetic diagnosis in patients with early age of presentation, higher birth weight and from consanguineous pedigrees.

Pancreatic endocrine and exocrine function in children following near-total pancreatectomy for diffuse congenital hyperinsulinism

Context

Congenital hyperinsulinism (CHI), the commonest cause of persistent hypoglycaemia, has two main histological subtypes: diffuse and focal. Diffuse CHI, if medically unresponsive, is managed with near-total pancreatectomy. Post-pancreatectomy, in addition to persistent hypoglycaemia, there is a very high risk of diabetes mellitus and pancreatic exocrine insufficiency.

Setting

International referral centre for the management of CHI.

Patients

Medically unresponsive diffuse CHI patients managed with near-total pancreatectomy between 1994 and 2012.

Intervention

Near-total pancreatectomy.

Main Outcome Measures

Persistent hypoglycaemia post near-total pancreatectomy, insulin-dependent diabetes mellitus, clinical and biochemical (faecal elastase 1) pancreatic exocrine insufficiency.

Results

Of more than 300 patients with CHI managed during this time period, 45 children had medically unresponsive diffuse disease and were managed with near-total pancreatectomy. After near-total pancreatectomy, 60% of children had persistent hypoglycaemia requiring medical interventions. The incidence of insulin dependent diabetes mellitus was 96% at 11 years after surgery. Thirty-two patients (72%) had biochemical evidence of severe pancreatic exocrine insufficiency (Faecal elastase 1<100 µg/g). Clinical exocrine insufficiency was observed in 22 (49%) patients. No statistically significant difference in weight and height standard deviation score (SDS) was found between untreated subclinical pancreatic exocrine insufficiency patients and treated clinical pancreatic exocrine insufficiency patients.

Conclusions

The outcome of diffuse CHI patients after near-total pancreatectomy is very unsatisfactory. The incidence of persistent hypoglycaemia and insulin-dependent diabetes mellitus is very high. The presence of clinical rather than biochemical pancreatic exocrine insufficiency should inform decisions about pancreatic enzyme supplementation.

Persistent hyperinsulinaemic hypoglycaemia in infancy

Persistent hyperinsulinaemic hypoglycaemia in infancy (PHHI) is a heterogeneous condition characterised by unregulated insulin secretion in response to a low blood glucose level. It is the most common cause of severe and persistent hypoglycaemia in neonates. It is extremely important to recognise this condition early and institute appropriate management to prevent significant brain injury leading to complications like epilepsy, cerebral palsy and neurological impairment. Histologically, PHHI is divided mainly into three types-diffuse, focal and atypical disease. Fluorine-18-l-3,4-dihydroxyphenylalanine positron emission tomography (18F-DOPA-PET/CT) scan allows differentiation between diffuse and focal diseases. The diffuse form is inherited in an autosomal recessive (or dominant) manner whereas the focal form is sporadic in inheritance and is localised to a small region of the pancreas. The molecular basis of PHHI involves defects in key genes (ABCC8, KCNJ11, GCK, SLC16A1, HADH, UCP2, HNF4A and GLUD1) that regulate insulin secretion. Focal lesions are cured by lesionectomy whereas diffuse disease (unresponsive to medical therapy) will require a near-total pancreatectomy with a risk of developing diabetes mellitus and pancreatic exocrine insufficiency. Open surgery is the traditional approach to pancreatic resection. However, recent advances in laparoscopic surgery have led to laparoscopic near-total pancreatectomy for diffuse lesions and laparoscopic distal pancreatectomy for focal lesions distal to the head of the pancreas.

The role of the resistive index in Hashimoto's thyroiditis: a sonographic pilot study in children

OBJECTIVE

The role of Doppler ultrasonography in the diagnosis of diffuse thyroid diseases is not well established. In particular, Doppler ultrasonography findings in children with Hashimoto's thyroiditis are very limited. We examined gray-scale and Doppler ultrasound findings in Hashimoto's thyroiditis in children in an attempt to understand the feasibility of future prospective controlled studies.

MATERIALS AND METHODS

Twenty-one children with newly diagnosed Hashimoto's thyroiditis were recruited in the study. The patients were euthyroid or had subclinical hypothyroidism at the time of the ultrasonography examination. According to the color Doppler scale developed by Schulz et al., thyroid glands were classified into four patterns based on visual scoring and the mean resistive index (RI), which was calculated via measurements from both lobes, and these results were compared with gray-scale findings.

RESULTS

The mean RI value, calculated as the mean of the RI values of both lobes obtained from each patient, was found to be 0.57 ± 0.05 (range 0.48-0.67) cm/sn. The distribution of thyroid classifications was as follows: Pattern 0, n = 7; Pattern I, n = 6; Pattern II, n = 4; and Pattern III ("thyroid inferno"), n = 4. The mean RI values in patients with normal or near-normal gray-scale findings (n = 10) and patients with more substantial gray-scale changes (n = 11) were not significantly different and were lower than the values in normal children previously presented in the literature.

CONCLUSION

The results indicated that the RI may be more sensitive than other ultrasound parameters for the diagnosis of Hashimoto's thyroiditis.

Assessment of gonadotrophin suppression in girls treated with GnRH analogue for central precocious puberty; validity of single luteinizing hormone measurement after leuprolide acetate injection

OBJECTIVE

Intravenous GnRH stimulation test has often been used as gold standard test for the evaluation of hypothalamic-pituitary-gonadal axis in the diagnosis of central precocious puberty (CPP) and in the assessment of pubertal suppression. However, this test is time-consuming, costly and uncomfortable for the patients. We aimed to analyse the validity of single LH sample 90 min after GnRH analogue (GnRHa) administration in the evaluation of gonadotrophin suppression during CPP therapy and to determine a cut-off level for LH indicating adequate suppression.

DESIGN

Prospective study.

PATIENTS AND METHODS

One hundred and forty-two patients with CPP were included in this study. Peak LH level during iv GnRH stimulation test after the third dose of GnRHa was compared with LH level 90 min after injection of the 3rd dose of GnRHa.

RESULTS

There was a positive correlation between LH level following a GnRHa injection and peak LH during standard iv GnRH stimulation test (r = 0·83; P < 0·0001). A LH value of 2·5 mIU/ml or less 90 min after GnRHa injection was considered to be the cut-off for the determination of pubertal suppression (sensitivity and specificity was 100% and 88%, respectively). In 117 patients, gonadotrophin suppression was existed according to both GnRHa and iv GnRH tests. In 25 patients, gonadotrophin suppression was not found in the GnRHa test. However, 16 of them were suppressed according to the iv GnRH test.

CONCLUSION

Single LH determination 90 min after GnRHa administration using a cut-off level of 2·5 mIU/ml reflects pubertal suppression with a high sensitivity and specificity. However, this test may fail to show pubertal suppression in some cases. Those patients who appear to be inadequately suppressed should be reassessed using standard iv GnRH stimulation test for optimal dose adjustment.

17beta-hydroxysteroid dehydrogenase type 3 deficiency as a result of a homozygous 7 base pair deletion in 17betaHSD3 gene

17-beta-Hydroxysteroid dehydrogenase type 3 (17betaHSD-3) converts delta4 androstenedione (A) to testosterone (T) in the testes. This enzyme plays a key role in androgen synthesis and it is essential for normal fetal development of male genitalia. 17betaHSD-3 deficiency is a rare cause of 46,XY disorders of sexual development. Here, we report a 16-year-old 46,XY patient with 17betaHSD-3 deficiency raised as a female and significantly virilized in puberty. A homozygous 7 base pair deletion on exon 10 was determined in HSD17B3 gene (c.777-783del_GATAACC). Our patient had one of the very rare mutations, which was previously unencountered in Turkish patients with 17betaHSD type 3, and she is the second reported case with this deletion.

Evaluation of serum kisspeptin levels in girls in the diagnosis of central precocious puberty and in the assessment of pubertal suppression

BACKGROUND

Onset of puberty is dependent on pulsatile secretion of gonadotropin releasing hormone (GnRH). The kisspeptin-GPR54 signaling system has a considerable role in GnRH physiology and induction of puberty.

OBJECTIVES

To evaluate kisspeptin levels in girls with central precocious puberty (CPP) at the time of the diagnosis and during follow-up, to determine whether or not kisspeptin may serve as a marker for diagnosis and follow-up of CPP.

PATIENTS AND METHODS

Kisspeptin levels of 28 girls with CPP were measured at the time of diagnosis and repeated at the 6th month of therapy after complete pubertal suppression and compared to kisspeptin levels of 13 age-matched prepubertal controls.

RESULTS

Kisspeptin levels of girls with CPP (10.2 +/- 2.6 pg/mL) were higher than those in controls (8.6 +/- 1.5 pg/mL (p = 0.019). There was a significant decline in the kisspeptin levels (7.3 +/- 1.3 pg/mL) of girls with CPP after pubertal suppression (p < 0.0001).

CONCLUSION

These findings suggest that kisspeptin levels can be used as corroborative evidence for diagnosis of CPP and a valuable parameter for monitoring treatment efficacy.

Two pediatric patients with Von Hippel-Lindau disease type 2b: from patient to screening, from screening to patient

Von Hippel-Lindau (VHL) disease is an autosomal dominantly inherited tumor susceptibility disease characterized by the development of hemangioblastomas of the brain, spinal cord and retina; pheochromocytomas and renal cell carcinoma. The disease is caused by mutations in the VHL tumor suppressor gene located on chromosome 3p26-p25. In this paper, we present two patients with VHL disease type 2B confirmed by genetic analysis. Diagnosis in the first patient was based on demonstration of retinal hemangioblastoma in association with bilateral pheochromocytoma. Family screening revealed renal cell carcinoma in her father and uncle. The second patient was discovered during family screening of another index case in adult age. VHL disease should be clinically suspected in any individual with a pheochromocytoma especially when there is bilateral and/or multifocal disease or family history. Screening of patients and at-risk family members for VHL-associated tumors should be essential in management of VHL.

Anemia and neutropenic fever with high dose diazoxide treatment in a case with hyperinsulinism due to Munchausen by proxy

BACKGROUND

The etiology of hyperinsulinemic hypoglycemia in adolescents is similar to that of adults. Patients resistant to medical treatment may undergo pancreatectomy. Diazoxide is the mainstay of medical treatment. Rarely bone marrow suppression is reported due to diazoxide.

PATIENT

An adolescent with severe hyperinsulinemic hypoglycemia was referred for pancreatectomy after she was treated with high doses of diazoxide, octreotide and glucose. She developed anemia and febrile neutropenia in the course of diazoxide treatment that resolved with cessation of medication. The cause of the hyperinsulinemia proved to be classical Munchausen by proxy.

CONCLUSION

This is the first report of bone marrow suppression involving erythroid series by diazoxide. Follow-up of blood count may be considered in patients on high dosages since anemia may be dose dependent. Munchausen by proxy poses a serious threat to children with significant morbidity and mortality. Awareness and a high index of suspicion in clinical settings with unusual causes are the mainstay for the diagnosis.

Assessment of thyroid function during the long course of Hashimoto's thyroiditis in children and adolescents

CONTEXT

The prognosis of Hashimoto's thyroiditis (HT) in children and adolescents is not well known and studies reporting long-term outcome of the disease are scarce.

OBJECTIVE

To assess the thyroid hormone status during long-term follow-up and to establish the prognosis of children and adolescents with HT.

PATIENTS

One hundred and twenty-nine patients with HT were re-evaluated for thyroid hormone status after a mean follow-up period of 50 months.

RESULTS

Seventy-seven per cent of the euthyroid patients were still euthyroid, while 21.1% of these patients became hypothyroid at the time of re-evaluation. However, 69.5% of hypothyroid patients remained hypothyroid (overt or subclinical) and 30.5% recovered.

CONCLUSION

HT is a dynamic process. Thyroid functions can show variation during follow-up. Therefore, thyroid function tests should be repeated periodically to detect progression to hypothyroidism in initially euthyroid patients as well as reversibility of hypothyroidism.

Hashimoto's thyroiditis in children and adolescents: a retrospective study on clinical, epidemiological and laboratory properties of the disease

Hashimoto's thyroiditis (HT) is the most common cause of goiter and acquired hypothyroidism in children and adolescents in iodine replete areas. To find out the clinical, epidemiological and laboratory characteristics of the disease in childhood, we reviewed files of 162 children and adolescents with HT followed in the Department of Pediatric Endocrinology, Hacettepe University Faculty of Medicine.

RESULTS

Female patients constituted 86.4% (n = 140) of all patients with a female:male ratio of 6.4. Mean age at diagnosis was 11.4 +/- 2.97 years (age range 4.4-16.5 years). At the time of diagnosis 43.2% of the patients (n = 70) were euthyroid, 24.1% (n = 39) had subclinical hypothyroidism, 21% (n = 34) had overt hypothyroidism, and 8.6% (n = 14) had overt and 3.1% (n = 5) subclinical hyperthyroidism.

CONCLUSIONS

Autoimmune thyroiditis is more frequent in females, and increases in frequency over age during childhood and adolescence. At the time of diagnosis, frequency of overt and subclinical hypothyroidism is similar to that of euthyroid goiter.