title: Congenital hypothyroidism with eutopic thyroid gland: analysis of clinical and biochemical features at diagnosis and after re-evaluation.
abstract: BACKGROUND
  In recent years changes in screening strategies for congenital hypothyroidism (CH) led to an increased detection of mild forms of CH, associated with eutopic thyroid gland.
  
  
  OBJECTIVE
  We aimed to determine the clinical evolution of CH with eutopic thyroid gland and to find out prognostic factors at diagnosis and follow-up.
  
  
  METHODS
  We retrospectively analyzed a group of 84 children with CH and eutopic thyroid gland treated at our institution. They all underwent clinical re-evaluation after the age of 3, based on thyroid function testing after l-thyroxine therapy withdrawal, thyroid ultrasonography, and (123)I scintigraphy with perchlorate discharge test. Genetic analysis was performed in selected cases.
  
  
  RESULTS
  At re-evaluation, 34.5% of patients showed permanent hypothyroidism and needed l-thyroxine reintroduction, 27.4% had persistent hyperthyrotropinemia (TSH 5-10 mU/L), and 38.1% had transient hypothyroidism. Major risk factors for permanent CH were prematurity, first-degree familial history of goiter/nodules, thyroid hypoplasia at diagnosis, and high l-thyroxine requirements at follow-up. Iodine organification defects were found in 29.7% of patients, 30% of whom harbored DUOX2 mutations. TSH receptor gene mutations were found in 8.7% of patients with persistent thyroid dysfunction and negative perchlorate discharge test.
  
  
  CONCLUSIONS
  Only one-third of patients with CH and eutopic thyroid gland needed to continue l-thyroxine therapy after re-evaluation. A frequent finding was the persistence of mild hyperthyrotropinemia. The evolution of CH remains difficult to predict, although different clinical features might suggest different outcomes. Mutations in the genes commonly linked to mild forms of CH were documented in a minority of cases.
authors: Department of Pediatrics, Vita-Salute San Raffaele University, Scientific Institute San Raffaele Hospital, Milan, Italy. rabbiosi.sarah@hsr.it
authors: Sarah
authors: S
authors: Rabbiosi
authors: Maria Cristina
authors: MC
authors: Vigone
authors: Francesca
authors: F
authors: Cortinovis
authors: Ilaria
authors: I
authors: Zamproni
authors: Laura
authors: L
authors: Fugazzola
authors: Luca
authors: L
authors: Persani
authors: Carlo
authors: C
authors: Corbetta
authors: Giuseppe
authors: G
authors: Chiumello
authors: Giovanna
authors: G
authors: Weber
mesh_terms: D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003409:Congenital Hypothyroidism / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D020249:Hormone Replacement Therapy; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology; D008297:Male; D011379:Prognosis; D012189:Retrospective Studies; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013974:Thyroxine / Q000627:therapeutic use; D014463:Ultrasonography
chemical_list: D013974:Thyroxine