title: Biochemical, radiological, and genetic characterization of congenital hypothyroidism in Abu Dhabi, United Arab Emirates.
abstract: BACKGROUND
  Congenital hypothyroidism (CH) is caused by thyroid gland (TG) dysgenesis or inadequate thyroid hormone biosynthesis in a structurally normal gland. Different etiologies are known to be associated with various clinical, biochemical and imaging markers and a subset of cases have an underlying genetic basis. Despite the presence of neonatal screening programs in the UAE, there is a lack of data on the disease etiology in the area. We aim to study the etiology of CH in our center and examine its relationship with the clinical, biochemical, genetic and radiological features.
  
  
  METHODS
  Patients with CH who were followed in our center between 2011 and 2014 are enrolled in the study. Data collected included gender, gestational age, history of CH in a first-degree relative, initial thyroid stimulating hormone (TSH) and thyroxine (T4) levels, imaging findings, associated disease/malformation and treatment details. Selected patients with associated systemic disease or familial CH underwent genetic testing.
  
  
  RESULTS
  Sixty-five patients were enrolled. Ten patients underwent genetic study: seven patients with associated congenital disease/malformation, one with a sibling and two with cousins with CH. Forty-nine subjects had technetium99 and/or ultrasound scans. Dyshormonogenesis was diagnosed in two-thirds of the patients. Three patients of 10 tested had likely causative genetic mutations; two homozygous thyroid peroxidase (TPO) and one heterozygous thyroid stimulating hormone receptor (TSHR) missense mutations.
  
  
  CONCLUSIONS
  Dyshormonogenesis is the commonest etiology in CH in the studied group. It is expected that genetic mutations are more prevalent in our region due to the nature of the CH etiology and the rate of high consanguinity rate.
authors.forename: Asma
authors.initials: A
authors.lastname: Deeb
authors.forename: Ihab
authors.initials: I
authors.lastname: Elkadry
authors.forename: Salima
authors.initials: S
authors.lastname: Attia
authors.forename: Hana
authors.initials: H
authors.lastname: Al Suwaidi
authors.forename: Laila
authors.initials: L
authors.lastname: Obaid
authors.forename: Nadia A
authors.initials: NA
authors.lastname: Schoenmakers
mesh_terms: D000293:Adolescent; D001324:Autoantigens / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003409:Congenital Hypothyroidism / Q000000981:diagnostic imaging / Q000208:ethnology / Q000235:genetics / Q000503:physiopathology*; D003241:Consanguinity; D005192:Family Health / Q000208:ethnology; D005260:Female; D005500:Follow-Up Studies; D006786:Hospitals, Urban; D006801:Humans; D007223:Infant; D007453:Iodide Peroxidase / Q000235:genetics; D033862:Iron-Binding Proteins / Q000235:genetics; D008297:Male; D009154:Mutation; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D011989:Receptors, Thyrotropin / Q000235:genetics; D012189:Retrospective Studies; D017556:Technetium Compounds / Q000008:administration & dosage; D013961:Thyroid Gland / Q000000981:diagnostic imaging / Q000503:physiopathology*; D014463:Ultrasonography; D014479:United Arab Emirates
chemical_list: D001324:Autoantigens; D033862:Iron-Binding Proteins; D019275:Radiopharmaceuticals; D011989:Receptors, Thyrotropin; D017556:Technetium Compounds; C056658:TPO protein, human; D007453:Iodide Peroxidase