Riza Taner Baran

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.

Incidence of type 1 diabetes mellitus in Turkish children from the southeastern region of the country: a regional report.

Objective: Variability in the incidence of type 1 diabetes mellitus (T1DM) related to geographical region, ethnic background, gender, and age indicates a need for further epidemiological studies. To date, there are no reported studies on the incidence of T1DM in the pediatric age group from the Southeastern region of Turkey. To define the incidence, demographic and clinical characteristics of T1DM in children 0-14 years of age in Diyarbakir, one of the largest cities in the Southeast region of Turkey. Methods: Hospital files of patients with the diagnosis of T1DM were reviewed. Data of all patients diagnosed between 1 June 2010 and 31 May 2011 were evaluated. Population data on the 0-14 age group were obtained from the Turkish Statistical Institute (TSI) reports. Results: From a total of 41 T1DM patients, 24 (58.5%) were female (male: 41.5%) with a male/female ratio of 1.4. The overall annual incidence of T1DM was 7.2/105, being 8.7/105 in females and 5.7/105 in males. The peak incidence was found to occur at age 5-9 years in the girls and 10-14 years in the boys. Mean age at diagnosis was 8.1±3.8 years. Rate of presentation with diabetic ketoacidosis was 65.9%. Patients applied most frequently in spring and winter months. Conclusions: In this first T1DM incidence study on the pediatric age group in Diyarbakir, Turkey, T1DM incidence was found to be similar to that in countries with low-middle incidence. Conflict of interest:None declared.

Bone Mineral Density in Adolescent Girls with Hypogonadotropic and Hypergonadotropic Hypogonadism.

Objective: Deficiency of sex steroids has a negative impact on bone mineral content. In studies conducted on postmenopausal women and animal studies, elevated follicle-stimulating hormone (FSH) levels were found to be correlated with a decrease in bone mineralization and osteoporosis. The aim of the present study was to evaluate bone mineral density (BMD) in adolescent girls with hypogonadotropic and hypergonadotropic hypogonadism and also to investigate the correlation between FSH level and BMD. Methods: The study group included 33 adolescent girls with hypogonadism (14 with hypogonadotropic hypogonadism and 19 with hypergonadotropic hypogonadism). FSH, luteinizing hormone, estradiol levels, and BMD (using dual energy x-ray absorptiometry) were measured. Results: There were no statistically significant differences between the chronological age and bone age of the two patient groups, namely, with hypogonadotropic and hypergonadotropic hypogonadism. There was also no significant difference between BMD z-score values obtained from measurements from the spine and the femur neck of patients in the two groups (p-values were 0.841 and 0.281, respectively). In the hypergonadotropic group, a moderately negative correlation was detected between FSH level and BMD z-score measured from the femur neck (ρ=-0.69, p=0.001), whilst no correlation was observed between FSH levels and height adjusted BMD-z scores measured from the spine (ρ=0.17, p=0.493). FSH level was not found to be an independent variable affecting BMD z-score. Conclusion: BMD z-scores were detected to be similar in adolescent girls with hypogonadotropic and hypergonadotropic hypogonadism, and FSH levels were not found to have a clinically relevant impact on BMD.

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.

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.

Genotype and Phenotype Characteristics in 22 Patients with Vitamin D-Dependent Rickets Type I.

Background and Aims: Vitamin D-dependent rickets type I (VDDR1) is an autosomal recessive disorder caused by mutations in the 25-hydroxyvitamin D 1-alpha-hydroxylase gene (CYP27B1). Mutations in CYP27B1 disrupt or lead to a total loss of the 1-α-hydroxylase activity and require treatment with physiological doses of calcitriol. Patients and Methods: A genetic analysis of the CYP27B1 gene was conducted in 22 Turkish patients with VDDR1 from 13 families. Presenting characteristics, biochemical features, treatment, and results from the genetic analysis are described. Results: A splice donor site mutation c.195 + 2T>G was found in 10 patients. The novel missense p.192K>E (c.574A>G) mutation was detected in 5 patients, and a novel missense p.197G>D (c.590G>A) mutation was found in 4 patients. A previously reported 7-bp duplication 1319-1325dupCCCACCC (Phe443Profs*24) in exon 8 was detected in 1 patient, and 1 patient was a compound heterozygote for the novel p.192K>E and the previously described 1319-1325dupCCCACCC mutations. A novel single base pair deletion, c.171_171delG, leading to a frameshift, was found in 1 patient. Conclusions: We identified 3 novel and 2 previously described mutations in the CYP27B1 gene. A marked phenotypical diversity was observed between families that carried identical mutations, suggesting phenotypical heterogeneity.

Mutations in BTD gene causing biotinidase deficiency: a regional report.

Abstract Biotinidase deficiency is an autosomal recessive inborn error of biotin metabolism. Children with biotinidase deficiency cannot cleave biocytin and, therefore, cannot recycle biotin. Untreated individuals become secondarily biotin deficient, which in turn results in decreased activities of the biotin-dependent carboxylases and the subsequent accumulation of toxic metabolites causing clinical symptoms. Biotinidase deficiency is characterized by neurological, cutaneous manifestations and metabolic abnormalities. The worldwide incidence of profound biotinidase deficiency has been estimated at 1:112,271. The human biotinidase gene is located on chromosome 3p25 and consists of four exons with a total length of 1629 base pairs. To date, more than 100 mutations in the biotinidase gene known to cause biotinidase deficiency have been reported. The vast majority of mutations are homozygous or compound heterozygous. Finding known mutations can be correlated with the biochemical enzymatic results. This report summarizes the demographic features of patients identified as biotinidase deficient from August of 2012 through August of 2013 and mutation analysis results for 20 cases in the southeast region of Turkey.

Obesity is a strong risk factor for the development of Restless Legs Syndrome and poor sleep quality in children and adolescents

Objective: Adult epidemiological studies suggest that the rate of Restless Legs syndrome (RLS) in the general population may range from 5% to 15%. The aim of this study was to investigate the frequency of RLS in a community sample of obese adolescents aged 10-16 years and to assess the association with sleep quality and health-related glucose metabolism markers. Methods: The study group comprised 144 obese and overweight children aged 10-16 yearsand the control group consisted of 66 age-matched healthy children. The RLS Questionnaire devised by the International RLS Study and the Pittsburgh Sleep Quality Index (PSQI), where a score >5 indicates poor sleep quality, was used to assess sleep quality. Results: Mean body mass index (BMI) of the overweight/obese and control groups were 30.5±0.5 and 18.7±0.2, respectively. The frequency of RLS was higher in the obese group (21.7%) than the overweight (3.4%) and control (1.5%) (p<0.001) groups. The frequency of a poor PSQI score was significantly higher (p<0.001) in the obese group (37.3%) than the control group (24.2%). The obese with RLS group also had poorer sleep quality scores than the non-RLS obese group. Many symptoms of sleep disruption were more common in obese patients with RLS and RLS was independently correlated with a high PSQI score [odds ratio (OR): 2.25, confidence interval (Cl): 0.96-5.28, p<0.001)] and an increased BMI z-score (OR: 8.87, Cl: 2.04-38.61, p<0.001). Conclusion: RLS is common in obese children and may be associated with altered sleep quality. Obese children with RLS need to be assessed since they may need support to improve their sleep quality.

Prepubertal Unilateral Gynecomastia: Report of 2 Cases

Prepubertal unilateral gynecomastia is an extremely rare condition. At present, its etiology and management strategy are not well known. Two unrelated prepubertal boys of ages 8 and 9 who presented with complaints of unilateral enlargement of breast tissue are reported. Physical examination, biochemical, hormonal and oncologic work-up findings were normal. Both patients were treated with peripheral liposuction successfully. Histopathological and immunohistochemical examinations showed benign fibroglandular gynecomastia and intensive (3+) estrogen receptor expression in 100% of periductal epithelial cells. Although an extremely rare and generally benign condition, patients with prepubertal unilateral gynecomastia should have a full endocrine and oncologic work-up.

Evaluation of Pediatric Voice Handicap Index in Children With Allergic Rhinitis

OBJECTIVE The study sought to determine impact of voice disability on children with allergic rhinitis (AR). The Turkish version of the Pediatric Voice Handicap Index (pVHI) was used to assess the impact of voice disability on functional, physical, and emotional aspects of voice and oral communication. The degree of talkativeness was also determined. METHODS One hundred twenty-three children with AR aged 6-17 years and age-matched 84 children of controls without present or past record of voice disorder were admitted in the cross-sectional study. The pVHI was carried out by an otolaryngologist. RESULTS Children with AR show higher scores on pVHI compared to healthy children, indicating a greater chance of voice disorders observed in them (P < 0.001). The scores of three domains and total score of pVHI were prevalent in children with AR. In addition, as the severity of AR increased, high scores of pVHI were observed (P = 0.044). The mean talkativeness scores in AR group were lower than those of the healthy controls (P < 0.001). CONCLUSION In children with AR, voice disorders are more frequently observed and correlate positively with AR severity.