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GÜRAN, TÜLAY

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Author: DEMİRCİOĞLU, SERAP × Has files: true ×

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    PublicationOpen Access
    A Rare Cause of Hypophosphatemia: Raine Syndrome Changing Clinical Features with Age
    (SPRINGER, 2020-07) DAĞÇINAR, ADNAN; Eltan, Mehmet; Alavanda, Ceren; Yavas Abali, Zehra; Ergenekon, Pinar; Yalindag Ozturk, Nilufer; Sakar, Mustafa; Dagcinar, Adnan; Kirkgoz, Tarik; Kaygusuz, Sare Betul; Gokdemir, Yasemin; Elcioglu, Huriye Nursel; Guran, Tulay; Bereket, Abdullah; Ata, Pinar; Turan, Serap
    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.
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    PublicationOpen Access
    Familial Hypomagnesemia with Hypercalciuria and Nephrocalcinosis Due to CLDN16 Gene Mutations: Novel Findings in Two Cases with Diverse Clinical Features
    (SPRINGER, 2021-11-11) BEREKET, ABDULLAH; Eltan, Mehmet; Abali, Zehra Yavas; Turkyilmaz, Ayberk; Gokce, Ibrahim; Abali, Saygin; Alavanda, Ceren; Arman, Ahmet; Kirkgoz, Tarik; Guran, Tulay; Hatun, Sukru; Bereket, Abdullah; Turan, Serap
    Biallelic loss of function mutations in the CLDN16 gene cause familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC), and chronic kidney disease. Here we report two cases of FHHNC with diverse clinical presentations and hypercalcemia in one as a novel finding. Pt#1 initially presented with urinary tract infection and failure to thrive at 5.5 months of age to another center. Bilateral nephrocalcinosis, hypercalcemia (Ca: 12.2 mg/dl), elevated parathyroid hormone (PTH) level, and hypercalciuria were detected. Persistently elevated PTH with high/normal Ca levels led to subtotal-parathyroidectomy at the age of 2.5. However, PTH levels remained elevated with progressive deterioration in renal function. At 9-year-old, she was referred to us for evaluation of hyperparathyroidism and, hypomagnesemia together with hypercalciuria, elevated PTH with normal Ca levels, and medullary nephrocalcinosis were detected. Compound heterozygosity of CLDN16 variants (c.715G>A, p.G239R; and novel c.360C>A, p.C120*) confirmed the diagnosis. Pt#2 was a 10-month-old boy, admitted with irritability and urinary crystals. Hypocalcemia, hypophosphatemia, elevated PTH and ALP, low 25(OH)D levels, and radiographic findings of rickets were detected. However, additional findings of hypercalciuria and bilateral nephrocalcinosis were inconsistent with the nutritional rickets. Low/normal serum Mg levels suggested the diagnosis of FHHNC which was confirmed genetically as a homozygous missense (c.602G > A; p.G201E) variant in CLDN16. Yet, hypocalcemia and hypomagnesemia persisted in spite of treatment. In conclusion, FHHNC may present with diverse clinical features with mild hypomagnesemia leading to secondary hyperparathyroidism with changing Ca levels from low to high. Early and accurate clinical and molecular genetic diagnosis is important for proper management.
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    PublicationOpen Access
    Homozygosity for a novel INHA mutation in two male siblings with hypospadias, primary hypogonadism, and high-normal testicular volume
    (2022-03-23) ŞAHİN, BAHADIR; DEMİRCİOĞLU, SERAP; BEREKET, ABDULLAH; GÜRAN, TÜLAY; Arslan Ateş E., Eltan M., Sahin B., Gurpinar Tosun B., Seven Menevse T., Geckinli B. B., Greenfield A., Turan S., Bereket A., Güran T.
    Background: The human INHA gene encodes the inhibin subunit alpha protein, which is common to both inhibin A and B. The functional importance of inhibins in male sex development, sexual function, and reproduction remain largely unknown. Objective: We report for the first time two male siblings with homozygous INHA mutations. Methods: The medical files were examined for clinical, biochemical, and imaging data. Genetic analysis was performed using next-generation and Sanger sequencing methods. Results: Two brothers complained of gynecomastia, testicular pain, and had a history of hypospadias. Biochemistry revealed low serum testosterone, high gonadotropin and anti-Mullerian hormone, and very low/undetectable inhibin concentrations, where available. Both patients had azoospermia in the spermiogram. We have identified a homozygous 2 bp deletion (c.208_209delAG, R70Gfs*3) variant, which leads to a truncated INHA protein in both patients, and confirmed heterozygosity in the parents. The external genital development, pubertal onset and progression, reproductive functions, serum gonadotropins, and sex hormones of mother and father, who were heterozygous carriers of the identified mutation, were normal. Conclusion: Homozygosity for INHA mutations causes decreased prenatal and postnatal testosterone production and infertility in males, while the heterozygous female and male carriers of INHA mutations do not have any abnormality in sex development and reproduction.
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    PublicationOpen Access
    Biallelic and monoallelic ESR2 variants associated with 46,XY disorders of sex development
    (2018-07) BEREKET, ABDULLAH; Baetens, Dorien; Güran, Tülay; Mendonca, Berenice B.; Gomes, Nathalia L.; De Cauwer, Lode; Peelman, Frank; Verdin, Hannah; Vuylsteke, Marnik; Van der Linden, Malaïka; Stoop, Hans; Looijenga, Leendert H.; De Bosscher, Karolien; Cools, Martine; De Baere, Elfride; Atay, Zeynep; Bereket, Abdullah; de Krijger, Ronald R.; Preter, Katleen de; Domenice, Sorahia; Turan, Serap
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    PublicationOpen Access
    A novel deletion involving the first GNAS exon encoding Gsα causes PHP1A without methylation changes at exon A/B
    (2022-04-01) BEREKET, ABDULLAH; DEMİRCİOĞLU, SERAP; GÜRAN, TÜLAY; Campbell D., Reyes M., Kaygusuz S. B., Abalı S., Güran T., Bereket A., Kagami M., Turan S., Jüppner H.
    © 2022Individuals 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.
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    PublicationOpen Access
    Homozygous Loss-of-function Mutations in SOHLH1 in Patients With Nonsyndromic Hypergonadotropic Hypogonadism
    (OXFORD UNIV PRESS INC, 2015-05) BEREKET, ABDULLAH; Bayram, Yavuz; Gulsuner, Suleyman; Guran, Tulay; Abaci, Ayhan; Yesil, Gozde; Gulsuner, Hilal Unal; Atay, Zeynep; Pierce, Sarah B.; Gambin, Tomasz; Lee, Ming; Turan, Serap; Bober, Ece; Atik, Mehmed M.; Walsh, Tom; Karaca, Ender; Pehlivan, Davut; Jhangiani, Shalini N.; Muzny, Donna; Bereket, Abdullah; Buyukgebiz, Atilla; Boerwinkle, Eric; Gibbs, Richard A.; King, Mary-Claire; Lupski, James R.
    Context: Hypergonadotropic hypogonadism presents in females with delayed or arrested puberty, primary or secondary amenorrhea due to gonadal dysfunction, and is further characterized by elevated gonadotropins and low sex steroids. Chromosomal aberrations and various specific gene defects can lead to hypergonadotropic hypogonadism. Responsible genes include those with roles in gonadal development or maintenance, sex steroid synthesis, or end-organ resistance to gonadotropins. Identification of novel causative genes in this disorder will contribute to our understanding of the regulation of human reproductive function. Objectives: The aim of this study was to identify and report the gene responsible for autosomal-recessive hypergonadotropic hypogonadism in two unrelated families. Design and Participants: Clinical evaluation and whole-exome sequencing were performed in two pairs of sisters with nonsyndromic hypergonadotropic hypogonadism from two unrelated families. Results: Exome sequencing analysis revealed two different truncating mutations in the same gene: SOHLH1 c.705delT (p.Pro235fs*4) and SOHLH1 c.27C>G (p.Tyr9stop). Both mutations were unique to the families and segregation was consistent with Mendelian expectations for an autosomal-recessive mode of inheritance. Conclusions: Sohlh1 was known from previous mouse studies to be a transcriptional regulator that functions in the maintenance and survival of primordial ovarian follicles, but loss-of-function mutations in human females have not been reported. Our results provide evidence that homozygous-truncating mutations in SOHLH1 cause female nonsyndromic hypergonadotropic hypogonadism.
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    PublicationOpen Access
    Constitutional Growth Delay Pattern of Growth in Velo-Cardio-Facial Syndrome: Longitudinal follow up and final height of two cases
    (2008) BEREKET, ABDULLAH; Turan, Serap; Ozdemir, Nihal; Güran, Tülay; Akalın, Figen; Akçay, Teoman; Ayabakan, Canan; Yılmaz, Yüksel; Bereket, Abdullah
    We report two patients with velo-cardio-facial syndrome (VCFS) who were admitted to our pediatric endocrinology clinic because of short stature and followed longitudinally until attainment of final height. Both patients followed a growth pattern consistent with constitutional delay of puberty with normal and near normal final height. Case 2 also had partial growth hormone (GH) deficiency and severe short stature (height SDS -3.4 SDS), but showed spontaneous catch-up and ended up with a final height of -2 SDS. These cases suggest that short stature in children with VCFS is due to a pattern of growth similar to that observed in constitutional delay of growth and puberty.
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    PublicationOpen Access
    Dysosteosclerosis: Clinical and radiological evolution reflecting genetic heterogeneity
    (2022-08-01) DEMİRCİOĞLU, SERAP; GÜRPINAR TOSUN, BUŞRA; GÜRAN, TÜLAY; BEREKET, ABDULLAH; ALAVANDA, CEREN; ARMAN, AHMET; DEMİRCİOĞLU S., Mumm S., ALAVANDA C., Kaygusuz B. S., GÜRPINAR TOSUN B., ARMAN A., Huskey M., GÜRAN T., Duan S., BEREKET A., et al.
    Dysosteosclerosis (DSS), the term coined in 1968 for ultrarare dysplasia of the skeleton featuring platyspondyly with focal appendicular osteosclerosis, has become generic by encompassing the genetic heterogeneity recently reported for this phenotype. We studied four unrelated Turkish patients with DSS to advance understanding of the new nosology. Patient 1 suffered femur fractures beginning at age 1 year. DSS was suspected from marked metaphyseal osteosclerosis in early childhood and subsequently platyspondyly accompanying patchy osteosclerosis of her appendicular skeleton. She harbored in SLC29A3, in 2012 the first gene associated with DSS, a unique homozygous duplication (c.303_320dup, p.102_107dupYFESYL). Patient 2 presented similarly with fractures and metaphyseal osteosclerosis but with no platyspondyly at age 2 months. She was homozygous for a novel nonsense mutation in SLC29A3 (c.1284C>G, p.Tyr428*). Patient 3 had ocular disease at age 2 years, presented for short stature at age 11 years, and did not begin to fracture until age 16 years. Radiographs showed mild platyspondyly and focal metaphyseal and femoral osteosclerosis. She was homozygous for a unique splice site mutation in TNFRSF11A (c.616+3A>G). Patient 4 at age 2 years manifested developmental delay and frequent infections but did not fracture. He had unique metadiaphyseal splaying and osteosclerosis, vertebral end-plate osteosclerosis, and cortical thinning of long bones but no mutation was detected of SLC29A3, TNFRSF11A, TCIRG1, LRRK1, or CSF1R associated with DSS. We find that DSS from defective SLC29A3 presents earliest and with fractures. DSS from compromised TNFRSF11A can lead to optic atrophy as an early finding. Negative mutation analysis in patient 4 suggests further genetic heterogeneity underlying the skeletal phenotype of DSS. (c) 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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    PublicationOpen Access
    The Etiology and Clinical Features of Non-CAH Gonadotropin-Independent Precocious Puberty: A Multicenter Study
    (ENDOCRINE SOC, 2016-05) BEREKET, ABDULLAH; Atay, Zeynep; Yesilkaya, Ediz; Erdeve, Senay Savas; Turan, Serap; Akin, Leyla; Eren, Erdal; Doger, Esra; Aycan, Zehra; Abali, Zehra Yavas; Akinci, Aysehan; Siklar, Zeynep; Ozen, Samim; Kara, Cengiz; Tayfun, Meltem; Sari, Erkan; Tutunculer, Filiz; Karabulut, Gulcan Seymen; Karaguzel, Gulay; Cetinkaya, Semra; Saglam, Halil; Bideci, Aysun; Kurtoglu, Selim; Guran, Tulay; Bereket, Abdullah
    Aim: The causes of gonadotropin-independent precocious puberty are diverse, and often have overlapping clinical and biochemical features. With the exception of congenital adrenal hyperplasia (CAH), disorders that cause gonadotropin-independent precocious puberty (GIPP) are uncommon. The literature is devoid of any large-scale studies on the etiologic distribution of GIPP. The aim of this study was to determine the frequency of each etiology in a cohort of patients with GIPP (excluding those with CAH), and to evaluate the clinical and laboratory features of these patients. Materials and Methods: This multicenter, nationwide web-based study collected data on patients who presented with non-CAH GIPP in Turkey. Results: Data were collected for 129 patients (102 girls and 27 boys) from 29 centers. Based on the data collected, the estimated prevalence of non-CAH GIPP in the studied population was 14 in 1 000 000 children. Functional ovarian cyst was the most common etiology, accounting for 37% of all cases, followed by McCune-Albright syndrome (MAS) (26%). Among the patients with MAS, 11.7% had fibrous dysplasia, 32.3% had caf-au-lait spots, and 52.9% had both. Human chorionic gonadotrophin-secreting tumors included choriocarcinoma of the liver, hepatoblastoma, and germ cell tumors of the sellar-suprasellar region and mediastinum. Patients with adrenocortical tumors presented at an earlier age than those with other etiologies. Ovarian tumors included mature cystic teratoma, dysgerminoma, juvenile granulosa tumor, and steroid cell tumor. Despite overlapping features, it was possible to identify some unique clinical and laboratory features associated with each etiology. Conclusion: This largest cohort of patients with non-CAH GIPP to date yielded an estimation of the frequency of non-CAH GIPP in the general pediatric population and showed that girls were affected at a rate 4-fold greater than that of boys owing to functional ovarian cysts and MAS, which were the two most common etiologies. The data collected also provided some unique characteristics associated with each etiology.
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    PublicationOpen Access
    Efficacy of the Novel Degludec/Aspart Insulin Co-formulation in Children and Adolescents with Type 1 Diabetes: A Real-life Experience with 1-year IDeg/Asp Therapy in Poorly Controlled and Non-compliant Patients
    (2021) BEREKET, ABDULLAH; Kirkgoz, Tarik; Eltan, Mehmet; Kaygusuz, Sare Betul; Yavas Abali, Zehra; Helvacioglu, Didem; Seven Menevse, Tuba; Gurpinar Tosun, Busra; Guran, Tulay; Bereket, Abdullah; Turan, Serap
    Objective: To evaluate efficacy of Degludec/Aspart (IDegAsp) insulin co-formulation in children and adolescents with poorly controlled type 1 diabetes (T1DM). Methods: A total of 50 patients with poorly-controlled T1DM on basal-bolus insulin regime and having compliance problems related to insulin injections and switched to IDegAsp were included. Data on HbA1c levels, hypoglycemic episodes, diabetic ketoacidosis (DKA) frequency and insulin doses were recorded at baseline and 1-year after the IDegAsp treatment. Results: Fifty patients (22 girls) were started on IDegAsp. The mean age and duration of diabetes were 12.9±3.4 (4-18) and 5.2±3.1 years (1.0-13.7), respectively. At the end of one year, 38 patients were still on IDegAsp, whereas 12 patients returned to their original treatments on their will. In those, who continued on IDegAsp, HbA1c levels did not change, but the number of self-reported mild-moderate hypoglycemia 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 1-year of IDegAsp therapy (p=0.06). Conclusion: IDegAsp regimen could be useful in T1DM patients poorly controlled on basal-bolus insulin regimen with frequent hypoglycemia and DKA attacks as well as a poor compliance with multiple injections. Although, simplified basal-bolus regimen with IDegAsp is an attractive option for the patients with T1DM, some of the patients may not adapt to the treatment due to fixed IAsp dose of IDegAsp.