title: First report of inherited thyroxine-binding globulin deficiency in Iran caused by a known de novo mutation in SERPINA7.
abstract: BACKGROUND
  Thyroxine-binding globulin (TBG) is the main transporter of thyroid hormones in human serum, encoded by the gene TBG (SERPINA7), located in long arm of X-chromosome (Xq21-q22). Deficiency of SERPINA7 (serum protease inhibitor, clade A [alpha-1 antiproteinase, antitrypsin], member 7) leads to inherited TBG deficiency. Several mutations have been reported in the coding and noncoding regions of SERPINA7 in association with TGB deficiency.
  
  
  METHODS
  Automated chemiluminescence immunoassays were used to determine TSH, free and total T4 and T3 (fT4, TT4, TT3) and TBG. Direct DNA sequencing identified the mutation in SERPINA7.
  
  
  RESULTS
  We present a 3 and 4/12 year old boy, born premature, who was mismanaged as hypothyroidism before referral to our center, and was diagnosed with TBG deficiency at our center with a hemizygous substitution in exon 1, position c.347T > A, leading to replacement of isoleucine for arginine in position 96 (considering the first 20 amino acid signal peptide).
  
  
  CONCLUSIONS
  This known mutation, reported as the first SERPINA7 mutation in Iran, emphasizes the point that endocrinologists should pay more attention to inherited TBG to prevent unnecessary treatment.
authors.affiliation: Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Fahimeh
authors.initials: F
authors.lastname: Soheilipour
authors.affiliation: Department of Medical Genetics and Molecular Biology, Iran University of Medical Sciences (IUMS), Tehran, Iran.
authors.forename: Hassan
authors.initials: H
authors.lastname: Fazilaty
authors.affiliation: Minimally Invasive Surgery Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Jesmi
authors.affiliation: NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH, Bethesda, MD, USA; Office of the Clinical Director, NHGRI, National Institutes of Health, Bethesda, MD, USA.
authors.forename: William A
authors.initials: WA
authors.lastname: Gahl
authors.affiliation: Department of Medical Genetics and Molecular Biology, Iran University of Medical Sciences (IUMS), Tehran, Iran; NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH, Bethesda, MD, USA; Office of the Clinical Director, NHGRI, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Babak
authors.initials: B
authors.lastname: Behnam
keywords: Iran; Mutation; SERPINA7; TBG