title: Early Discrimination between Transient and Permanent Congenital Hypothyroidism in Children with Eutopic Gland.
abstract: OBJECTIVE
  To analyze the factors that might allow an early discrimination between permanent (P) and transient (T) congenital hypothyroidism (CH).
  
  
  METHODS
  Clinical, biochemical and imaging data of 64 children with eutopic gland, who were positively screened and treated for CH during the period 1998-2011, were retrospectively analyzed.
  
  
  RESULTS
  During a 3-year treatment period, the mean doses of <smlcap>L</smlcap>-thyroxine (L-T4) per kilogram of body weight at various times were significantly lower in the 46 children with T CH than in the remaining 18 with P CH. No patients with T CH had required any increment of the doses of L-T4 per kilogram of body weight to maintain normal thyroid-stimulating hormone levels over time, whereas 16/18 children with P CH during the same period had needed some dose increments (p < 0.0001).
  
  
  CONCLUSIONS
  (a) L-T4 requirements >4.9 µg/kg/day at 12 months or >4.27 µg/kg/day at 24 months are highly suggestive of P CH, irrespective of gland ultrasonography; (b) L-T4 requirements <1.7 µg/kg/day at 12 months or <1.45 µg/kg/day at 24 months are highly suggestive of T CH, at least in the cases with eutopic gland, and (c) the analysis of L-T4 requirements during the first years of treatment might allow an early discrimination between T and P CH in the cases with eutopic gland.
authors.affiliation: Department of Pediatric, Gynecological, Microbiological and Biomedical Sciences, University of Messina, Messina, Italy.
authors.forename: Maria Francesca
authors.initials: MF
authors.lastname: Messina
authors.forename: Tommaso
authors.initials: T
authors.lastname: Aversa
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Salzano
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Zirilli
authors.forename: Concetta
authors.initials: C
authors.lastname: Sferlazzas
authors.forename: Filippo
authors.initials: F
authors.lastname: De Luca
authors.forename: Fortunato
authors.initials: F
authors.lastname: Lombardo
mesh_terms: D002648:Child; D002675:Child, Preschool; D003409:Congenital Hypothyroidism / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015997:Neonatal Screening; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013961:Thyroid Gland / Q000000981:diagnostic imaging / Q000473:pathology*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014463:Ultrasonography
chemical_list: D013972:Thyrotropin; D013974:Thyroxine