Person: KIRKGÖZ, TARIK
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KIRKGÖZ
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TARIK
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Publication Open 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, SerapRaine 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.Publication Open 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, SerapBiallelic 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.Publication Metadata only Does Genotype-Phenotype Correlation Exist in Vitamin D-Dependent Rickets Type IA: Report of 13 New Cases and Review of the Literature(SPRINGER, 2021) BEREKET, ABDULLAH; Kaygusuz, Sare Betul; Alavanda, Ceren; Kirkgoz, Tarik; Eltan, Mehmet; Yavas Abali, Zehra; Helvacioglu, Didem; Guran, Tulay; Ata, Pinar; Bereket, Abdullah; Turan, SerapVitamin D-dependent rickets type IA (VDDR-IA) is caused by biallelic mutations in CYP27B1. Data regarding genotype-phenotype correlation in VDDR-IA are scarce. Here, we aimed to investigate clinical/genotypic features and long-term follow-up of 13 new cases with VDDR-IA and genotype-phenotype correlation of reported cases in the literature. Thirteen patients with VDDR-IA were evaluated. Eight patients had reached their final height at the time of the study and, for whom, long-term outcome data were analyzed. Further, all VDDR-IA patients in the literature (n:183) were analyzed and clinical-genetic features were recorded. The median age of diagnosis was 2.55 +/- 1.13 (1.0-12) years. Initial diagnoses before referral to our clinic were nutritional rickets (n:7), hypophosphatemic rickets (n:2), and pseudohypoparathyroidism (n:1). All had biochemical evidence suggestive of VDDR-IA; except one with elevated 1,25(OH)(2)D3 and another with hyperphosphatemia, in whom pseudohypoparathyroidism was excluded with molecular tests. Combined analyses of our cohort and other series in the literature demonstrated that three most common CYP27B1 mutations are p.F443Pfs*24, c.195 + 2T > G, and p.V88Wfs*71. In Turkish population, p.K192E mutation along with the former two is the most common mutations. Comparison of clinical features demonstrated that c.195 + 2T > G mutation causes the most severe and p.K192E mutation causes the least severe phenotype with respect to age and height at presentation and calcitriol requirement. We found a clear genotype-phenotype correlation in VDDR-IA, notably CYP27B1 intronic c.195 + 2T > G mutation causes a more severe phenotype with lower height SDS at presentation and, higher calcitriol requirement, while less severe phenotype occurs in p.K192E mutation.Publication Metadata only Challenges in the management of a 7 years old child with thyrotropin-secreting pituitary adenoma and the review of the literature(2023-01-01) KIRKGÖZ, TARIK; GÜRPINAR TOSUN, BUŞRA; ELTAN, MEHMET; HALİLOĞLU, BELMA; KAYGUSUZ, SARE BETÜL; SEVEN MENEVŞE, TUBA; BOZKURT, SÜHEYLA; ÖNEŞ, TUNÇ; GÜRAN, TÜLAY; DAĞÇINAR, ADNAN; BEREKET, ABDULLAH; DEMİRCİOĞLU, SERAP; KIRKGÖZ T., Abali S., Seker A., GÜRPINAR TOSUN B., ELTAN M., Helvacioglu D., HALİLOĞLU B., KAYGUSUZ S. B., Yavas Abali Z., SEVEN MENEVŞE T., et al.Introduction: Thyrotropin-producing pituitary adenoma (TSHoma) is a very rare disease, representing less than 1% of the pituitary tumours, present with elevated thyroid hormones and normal/high TSH concentrations. Case Presentation: A 7-year-old boy with nervousness was referred by his psychiatrist for elevated free T4, T3 and TSH levels. Initial evaluation revealed an elevated -subunit.Pituitary MRI demonstrated a macroadenoma. The patient underwent a trans-sphenoidal tumour resection (TSS) which showed positive immunohistochemical staining for TSH, growth hormone, and prolactin in tumoral tissue. Euthyroidism was achieved for one year after TSS, then, recurrence of tumour with elevated TSH and thyroid hormone levels necessitated a re-operation with TSS followed by gamma-knife radiosurgery. The euthyroid state was achieved and lasted for 2.5 years this time, but, due to the recurrence, medical treatment had been commenced with cabergoline and octreotide. Euthyroidism was maintained for the last 4 years on monthly octreotide treatment. A repeat MRI demonstrated no pituitary mass but a mass in the sphenoidal sinus had been detected. Removal of this mass by surgery did not achieve euthyroidism. 68Ga-DOTA-TATE PET/CT showed residual tissue extending from the pituitary region to the sphenoid sinus.The patient\"s bone age was advanced 2 years at diagnosis which became 4 years in one year after the diagnosis and remained so throughout follow-up, leading to a final height of -3.3 SDS below his target height at the age of 16 years. Conclusion: The diagnosis, treatment, and follow-up of TSHomas are challenging and short stature due to accelerated bone maturation is a complication of paediatric TSHomas.Publication Metadata only Cinacalcet as a First-Line Treatment in Neonatal Severe Hyperparathyroidism Secondary to Calcium Sensing Receptor (CaSR) Mutation(KARGER, 2020) BEREKET, ABDULLAH; Gulcan-Kersin, Sinem; Kirkgoz, Tarik; Eltan, Mehmet; Rzayev, Turkay; Ata, Pinar; Bilgen, Hulya; Ozek, Eren; Bereket, Abdullah; Turan, SerapIntroduction: Neonatal severe hyperparathyroidism (NSHPT) is a rare cause of neonatal hypercalcemia caused by a loss of function mutation in the calcium-sensing receptor (CaSR). Hypercalcemia in NSHPT can be life-threatening. Maintenance of serum calcium within a safe range is the primary goal of treatment through hydration, forced diuresis, and bisphosphonate treatment, nevertheless most cases require parathyroidectomy. We report a case with NSHPT diagnosed on the first day of life (DoL) and successfully treated with cinacalcet as the first-line treatment from the 2nd DoL up to the age of 18 months. Case Report: A full-term baby evaluated for weight loss at postnatal 14th hour and found to have hypercalcemia (14.4 mg/dL, reference range [RR]: 8.0-11.3). Despite hydration and diuresis, hypercalcemia persisted. Further evaluation revealed a parathyroid hormone (PTH) level of 1,493 pg/mL (RR: 15-65) and urine Ca/Cr of 0.09 mg/mg (RR: 0.03-0.81). Cinacalcet treatment was initiated on the 2nd DoL with the diagnosis of NSHPT due to hypocalciuric hypercalcemia and elevated PTH level. Ca levels decreased to normal levels on the 7th DoL. She was discharged from hospital at postnatal day 15 on cinacalcet treatment and still continued at 18 months of age. Sequencing of CaSR revealed a novel homozygous c.1836G>A (p.G613E) mutation in the patient, for which the parents and sister were heterozygous. Conclusion: This case represents the youngest age at cinacalcet initiation and the longest duration without parathyroidectomy in a homozygous NSHPT and demonstrates that cinacalcet is an effective first-line treatment in patients who are responsive to this treatment modality and allows avoiding/delay in surgical intervention in NSHPT.Publication Metadata only Molecular analysis of MKRN3 gene in Turkish girls with sporadic and familial idiopathic central(2023-03-01) KIRKGÖZ, TARIK; KAYGUSUZ, SARE BETÜL; ALAVANDA, CEREN; GÜRPINAR TOSUN, BUŞRA; ELTAN, MEHMET; SEVEN MENEVŞE, TUBA; GÜRAN, TÜLAY; ARMAN, AHMET; DEMİRCİOĞLU, SERAP; BEREKET, ABDULLAH; KIRKGÖZ T., KAYGUSUZ S. B., ALAVANDA C., Helvacioglu D., Abali Z. Y., GÜRPINAR TOSUN B., ELTAN M., SEVEN MENEVŞE T., GÜRAN T., ARMAN A., et al.Objectives: Central precocious puberty (CPP) develops as a result of early stimulation of the hypothalamic-pituitary-gonadal (HPG) axis. The loss-of-function mutations in the Makorin-ring-finger3 (MKRN3) gene appear to be the most common molecular cause of familial CPP. We aimed to identify MKRN3 gene mutations in our CPP cohort and to investigate the frequency of MKRN3 mutations.Methods: 102 patients with CPP included. 53 of them had family history of CPP in the first and/or second-degree relatives. MKRN3 gene was analyzed by next-generation sequencing.Results: Possible pathogenic variants were found in 2/53 patients with family history of CPP (3.8%) and 1/49 patient without family history (2%). A novel heterozygous c.1A > G (p.Met1Val) mutation, a novel heterozygous c.683_684delCA (p.Ser228*) and a previously reported c.482dupC (Ala162Glyfs*) frameshift variations were detected. The two novel variants are predicted to be pathogenic in silico analyses.Conclusions: In our cohort, possible pathogenic variants in MKRN3 gene were detected in 2.9% of the total cohort, 3.8% of the familial and 2% of the nonfamilial cases, slightly lower than that reported in the literature. Two novel variants detected contribute to the molecular repertoire of MKRN3 defects in CPP. Classical pattern of paternal inheritance has been demonstrated in all three cases. However, the father of the patient 3 did not have history of CPP suggesting that the father inherited this variant from his mother and had phenotype skipping. Therefore, we emphasize that the absence of history of CPP in the father does not exclude the possibility of a MKRN3 mutation.Publication Metadata only Evaluation of growth and puberty in a child with a novel TBX19 gene mutation and review of the literature(SPRINGER INTERNATIONAL PUBLISHING AG, 2019) BEREKET, ABDULLAH; Abali, Zehra Yavas; Yesil, Gozde; Kirkgoz, Tarik; Kaygusuz, Sare Betul; Eltan, Mehmet; Turan, Serap; Bereket, Abdullah; Guran, TulayBackground Biallelic mutations in the TBX19 gene cause severe early-onset adrenal failure due to isolated ACTH deficiency (IAD). This rare disease is characterized by low plasma ACTH and cortisol levels, with normal secretion of other pituitary hormones. Herein, we report a patient with IAD due to a novel TBX19 gene mutation, who is also of tall stature. Case report A 4(8/12)-year-old girl was presented with loss of consciousness due to hypoglycemia. The patient was born at term with a birth weight of 3800 g. Her parents were first-degree cousins. She had a history of several hospitalizations for recurrent seizures, abdominal pain, and vomiting. At presentation, her weight and height were + 1.8 and + 2.2 SDS, respectively. Serum glucose was 25 mg/dl (1.4 mmol/L), with normal sodium, potassium, and insulin concentrations. The child was hypocortisolemic (0.1 mu g/dl), and ACTH levels were extremely low (< 5.0 pg/ml). A diagnosis of IAD was made and hydrocortisone treatment was started. Hypoglycemic episodes, seizures, and recurrent gastrointestinal complaints disappeared after hydrocortisone replacement. Magnetic resonance imaging of the pituitary was normal. Whole exome sequencing revealed a novel homozygous c.302G > A (W101*) mutation in the TBX19 gene. Conclusion We report a new mutation in the TBX19 gene in a patient with isolated ACTH deficiency. While overgrowth is a known feature of some types of adrenal insufficiencies, including MC2R gene defects and POMC deficiency, it may be a novel feature for TPIT deficiency, as in our patient.Publication Metadata only Low DHEAS Concentration in a Girl Presenting with Short Stature and Premature Pubarche: A Novel PAPSS2 Gene Mutation(KARGER, 2020) BEREKET, ABDULLAH; Eltan, Mehmet; Yavas Abali, Zehra; Arslan Ates, Esra; Kirkgoz, Tarik; Kaygusuz, Sare Betul; Turkyilmaz, Ayberk; Bereket, Abdullah; Turan, Serap; Guran, TulayObjective: Dehydroepiandrosterone (DHEA) sulfotransferase (SULT2A1) converts DHEA to DHEA sulfate (DHEAS) which prevents bioactive androgen excess. This enzymatic reaction requires PAPS (3 '-phospho-adenosine-5 '-phosphosulfate) biosynthesis mediated by PAPS synthase 2 (PAPSS2). Here, we report a patient presenting with short stature and premature pubarche due to a novel homozygous mutation in the PAPPS2 gene. Case Report: A 7.5-year-old girl was referred for short stature. She was born at term with a birth weight of 2,850 g and her parents were first cousins. At presentation, her height was 113.0 cm (-2.1 SDS) and weight was 28.3 kg (+0.9 SDS), her arm span was 115.0 cm, and upper to lower segment ratio was 1.2. Her pubic hair and breast development were at Tanner stage III and I, respectively. Radiographs revealed mild lumbar scoliosis and platyspondyly and irregular vertebral endplates in the thoracolumbar region. Her serum DHEAS was low (39 ng/mL). The plasma DHEAS/DHEA ratio was significantly decreased on 2 separate measurements (4.4 and 19.8; normal range 31-345). PAPSS2 gene analysis identified a homozygous p.L440Wfs*12 (c.1318_1330 delCTACTACACCCTC) variant. This is the first report of a large deletion leading to a frameshift effect in the PAPSS2 gene and a truncated PAPSS2 protein. Conclusion: We describe the third case with PAPSS2 deficiency presenting with premature pubarche, and the first large deletion in the PAPSS2 gene. Although PAPSS2 deficiency is a rare cause of premature pubarche and adrenal androgen excess, it should be considered, especially in cases with disproportionate short stature and clinical hyperandrogenism associated with low plasma DHEAS concentration.