title: The absence of mutations in homeobox candidate genes HOXA3, HOXB3, HOXD3 and PITX2 in familial and sporadic thyroid hemiagenesis.
abstract: BACKGROUND
  The molecular mechanisms leading to the formation of the two thyroid symmetrical lobes, which are impaired in thyroid hemiagenesis (TH), are little known.
  
  
  OBJECTIVE
  The aim of this work was to search for mutations in thyroid developmental candidate genes HOXA3, HOXB3, HOXD3 and PITX2.
  
  
  METHODS
  Total DNA from peripheral blood was extracted and then the entire coding region of all these genes was amplified by polymerase chain reaction and direct sequencing.
  
  
  RESULTS
  Herein we describe familial cases of TH in two generations (proband and his father), in addition to other two sporadic cases. We have found polymorphisms in the HOXB3 (rs2229304), HOXD3 (rs34729309, rs1051929, c.543-199G>T and c.543-34G>A; and a new synonymous variant, NP_008829.3:p.314;C>G) and PITX2 (c.45+76C>T) genes, but no deleterious mutations.
  
  
  CONCLUSIONS
  These results suggest the existence of other left-right thyroid asymmetry candidate genes in humans such as classical Mendelian mutation-causing disease, as well as other etiopathogenic mechanisms such as epigenetic modifications, especially for sporadic hemiagenesis.
authors.forename: Marina M L
authors.initials: MM
authors.lastname: Kizys
authors.forename: Suzana
authors.initials: S
authors.lastname: Nesi-França
authors.forename: Mirian G
authors.initials: MG
authors.lastname: Cardoso
authors.forename: Michelle Y
authors.initials: MY
authors.lastname: Harada
authors.forename: Maria Clara C
authors.initials: MC
authors.lastname: Melo
authors.forename: Maria Izabel
authors.initials: MI
authors.lastname: Chiamolera
authors.forename: Magnus R
authors.initials: MR
authors.lastname: Dias-da-Silva
authors.forename: Rui M B
authors.initials: RM
authors.lastname: Maciel
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D005801:Genes, Homeobox; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D009154:Mutation; D016133:Polymerase Chain Reaction; D050033:Thyroid Dysgenesis / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D000097577:Homeobox Protein PITX2
chemical_list: D017931:DNA Primers; D018398:Homeodomain Proteins; D014157:Transcription Factors; D000097577:Homeobox Protein PITX2