title: Six new mutations of the thyroglobulin gene discovered in taiwanese children presenting with thyroid dyshormonogenesis.
abstract: BACKGROUND
  Thyroglobulin (TG) defect is a rare cause of congenital hypothyroidism. Although only 44 mutations of the human TG gene have been identified, we have suspected a TG defect in 38% of Taiwan Chinese children/adolescents presenting with moderate or severe thyroidal dyshormonogenesis.
  
  
  OBJECTIVE
  The aim of the study is to report the discovery of new TG gene mutations and associated clinical manifestations of the defective TG protein.
  
  
  RESULTS
  In seven patients from six families, we detected six new TG gene mutations, including c.1348delT, p.R432X (c.1351C>T), g.IVS3 + 2T>G, c.1712delT, p.Q1765X (c.5350C>T), and c.6047delA. The c.1348delT and p.R432X mutations were the most common, detected in 33 and 25%, respectively, of alleles studied. Haplotype analysis suggested that the c.1348delT and g.IVS3 + 2T>G mutations are due to founder effects, whereas p.R432X is probably due to independently recurrent de novo mutations. mRNA transcript of the g.IVS3 + 2T>G mutant, detected in whole blood by reverse transcription-nested PCR, showed skipping of exon 3 (98-bp deletion) and a frameshift, with a terminal signal after 17 altered amino acid residues.
  
  
  CONCLUSIONS
  TG defects have an important role in severe thyroidal dyshormonogenesis (pretreatment, or after a 3-wk T(4) withdrawal, plasma T(4) < or = 30 nmol/liter) in Taiwanese. Its genetic characteristics are markedly different from those described in other populations presenting with mutations of the TG gene.
authors.affiliation: Institute of Clinical Medicine, National Yang-Ming University, Taipei 112, Taiwan. dmniu1111@yahoo.com.tw
authors.forename: Dau-Ming
authors.initials: DM
authors.lastname: Niu
authors.forename: Ju-Hui
authors.initials: JH
authors.lastname: Hsu
authors.forename: Kah-Wai
authors.initials: KW
authors.lastname: Chong
authors.forename: Cheng-Hung
authors.initials: CH
authors.lastname: Huang
authors.forename: Yung-Hsiu
authors.initials: YH
authors.lastname: Lu
authors.forename: Chuan-Hong
authors.initials: CH
authors.lastname: Kao
authors.forename: Hsiao-Chi
authors.initials: HC
authors.lastname: Yu
authors.forename: Ming-Yu
authors.initials: MY
authors.lastname: Lo
authors.forename: Tjin-Shing
authors.initials: TS
authors.lastname: Jap
mesh_terms: D000293:Adolescent; D000483:Alleles; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D005091:Exons; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D009154:Mutation / Q000235:genetics / Q000502:physiology; D010641:Phenotype; D012333:RNA, Messenger / Q000235:genetics; D013624:Taiwan; D013954:Thyroglobulin / Q000235:genetics*; D050033:Thyroid Dysgenesis / Q000235:genetics*; D013960:Thyroid Function Tests
chemical_list: D012333:RNA, Messenger; D013954:Thyroglobulin