Person: BAYRAKTAR, BILGE
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Publication Metadata onlyRecurrence of carbamoyl phosphate synthetase 1 (CPS1) deficiency in Turkish patients: Characterization of a founder mutation by use of recombinant CPS1 from insect cells expression(2014-12-01T00:00:00Z) Hu, Liyan; Diez-Fernandez, Carmen; Ruefenacht, Veronique; Hismi, Burcu Ozturk; Unal, Ozlem; SOYUÇEN, ERDOĞAN; ÇOKER, MAHMUT; BAYRAKTAR, Bilge; Gunduz, Mehmet; KIYKIM, Ertuğrul; Olgac, Asburce; Perez-Tur, Jordi; Rubio, Vicente; Haeberle, Johannes; BAYRAKTAR, BILGECarbamoyl phosphate synthetase 1 (CPS1) deficiency due to CPS1 mutations is a rare autosomal-recessive urea cycle disorder causing hyperammonemia that can lead to death or severe neurological impairment. CPS1 catalyzes carbamoyl phosphate formation from ammonia, bicarbonate and two molecules of ATP, and requires the allosteric activator N-acetyl-L-glutamate. Clinical mutations occur in the entire CPS1 coding region, but mainly in single families, with little recurrence. We characterized here the only currently known recurrent CPS1 mutation, p.Val1013del, found in eleven unrelated patients of Turkish descent using recombinant His-tagged wild type or mutant CPS1 expressed in baculovirus/insect cell system. The global CPS1 reaction and the ATPase and ATP synthesis partial reactions that reflect, respectively, the bicarbonate and the carbamate phosphorylation steps, were assayed. We found that CPS1 wild type and V1013del mutant showed comparable expression levels and purity but the mutant CPS1 exhibited no significant residual activities. In the CPS1 structural model, V1013 belongs to a highly hydrophobic beta-strand at the middle of the central beta-sheet of the A subdomain of the carbamate phosphorylation domain and is close to the predicted carbamate tunnel that links both phosphorylation sites. Haplotype studies suggested that p.Val1013del is a founder mutation. In conclusion, the mutation p.V1013del inactivates CPS1 but does not render the enzyme grossly unstable or insoluble. Recurrence of this particular mutation in Turkish patients is likely due to a founder effect, which is consistent with the frequent consanguinity observed in the affected population. (C) 2014 Elsevier Inc All rights reserved. Publication Open AccessUmbilical cord levels of macrophage migration inhibitory factor in neonatal respiratory distress syndrome(2021-01-01T00:00:00Z) Bayraktar, Suleyman; BAYRAKTAR, Bilge; Kilic, Ulkan; BAYRAKTAR, BILGEBackground/aim: We aimed to evaluate the association of the umbilical cord macrophage migration inhibitory factor (MIF) with the respiratory distress syndrome (RDS) in preterm infants. Materials and methods: A total of eighty six preterm infants (38 with RDS and 48 without RDS) were involved in the study. ELISA is the technique assaying MIF values. Results: The mean of the infants’ gestational ages and birth weights were significantly different (P = 0.0001). There were no significant differences in sex, delivery mode or exposure to antenatal steroid among the groups (P > 0.05). Umbilical cord MIF levels of the infants were not correlated with gestational age and birth weight (Spearman’s rho = –0.22 and 0.28 respectively, P > 0.05). There was no statistically significant difference in umbilical cord MIF levels of infants whether or not they were administered antenatal steroid (median:17.88 vs. median:17.60, Mann–Whitney U test, P = 0.42). Cord serum MIF levels were higher (mean, 17.09 ± 5.86 ng/mL) in the RDS group than in the non-RDS group (mean, 14.72 ± 4.18 ng/mL) (P = 0.005). Conclusion: This study shows that, MIF level is higher in the cord blood of the infants with RDS than of the infants without RDS. This supports that MIF expression begins in prior to the birth of the preterm infants and MIF has enhancing impact on the lung development of premature babies. With future studies, the assessment of the cord MIF levels at the bedside may be beneficial for the diagnosis and treatment of RDS, and taking actions to prevent long-term consequences. Publication Open AccessInfantile Pompe Disease Presenting with Severe Hypertrophic Cardiomyopathy: A Case Report(2015-09-01T00:00:00Z) Bayraktar, Suleyman; BAYRAKTAR, Bilge; Elevli, Murat; BAYRAKTAR, BILGEInfantile Pompe disease (glycogen storage disease type 2) is a fatal disease with autosomal recessive inheritance, leading to hypertrophic cardiomyopathy, hypotonia and respiratory failure. It is a progressive condition due to accumulation of glycogen in the muscles. We aimed to present a case of infantile Pompe disease in a patient who had giant QRS complexes in electrocardiographic monitoring and hypertrophic cardiomyopathy involving the interventricular septum and the left ventricle on echocardiography. Publication Metadata onlyFreeman-Sheldon Syndrome Associated with Hemophilia-A in a Newborn(2016-12-01T00:00:00Z) BAYRAKTAR, Bilge; Bayraktar, Suleyman; ARSLAN, HÜSEYİN; ÇAKIR, FATMA BETÜL; BAYRAKTAR, BILGE; ÇAKIR, FATMA BETÜLThe Freeman-Sheldon syndrome (FSS) (whistling face) is a congenital autosomal dominant disease (rarely described in its autosomal recessive form) characterized by small -whistling- mouth, a flat masklike face, joint contractures (commonly involving the fingers and hands) and underdevelopment of the nasal cartilage. Other clinical features include full forehead, deep set eyes, epicanthal folds, high palate, H-shaped cutaneous dimpling on the chin, ulnar deviation of the hands, seizures, and dislocation of the hip. A 10-day-old male newborn was admitted to our neonatal intensive care unit with jaundice and hyperthermia. He had fever of 42.5 degrees C, small whistling mouth, a flat mask-like face, joint contractures of the fingers, and ulnar deviation of the hands. The parents were consanguineous and one of the boys died when he was 1 years old due to intracranial hemorrhage. To our knowledge, there have been more than 60 cases diagnosed with FSS. This is the first reported case of Freeman-Sheldon syndrome associated with hemophilia A and the second case of FSS associated with fever without anesthesia.