title: McCune-Albright syndrome in a discordant monozygotic twin.
abstract: BACKGROUND
  McCune-Albright syndrome is a sporadic disorder characterized by polystotic fibrous dysplasia, pigmented patches of skin, and endocrinological abnormalities.
  
  
  OBJECTIVE
  To compare the genetic characteristics of the GNAS1 gene in a monozygotic pair of twins, one of whom was diagnosed with MAS while the other had no indication of the syndrome.
  
  
  METHODS
  We performed a molecular analysis of the GNAS1 gene in DNA extracted from peripheral blood cells and quantification of mRNA extracted from lymphoblastoid cells from both twins by quantitative real-time polymerase chain reaction.
  
  
  RESULTS
  Monozygosity of the twins was confirmed by typing them to four highly polymorphic microsatellites. Molecular analysis of the GNAS1 gene extracted from both twins did not reveal the cause of this discordance.
  
  
  CONCLUSIONS
  It is possible that the exact molecular mechanism for the MAS discordance can only be determined by sampling affected tissues.
authors.affiliation: Department of Family Medicine, Ben-Gurion University of the Negev, Beer Sheva, Israel. pelegr@bgu.ac.il
authors.forename: Roni
authors.initials: R
authors.lastname: Peleg
authors.forename: Avizov
authors.initials: A
authors.lastname: Luba
authors.forename: Alon
authors.initials: A
authors.lastname: Eliakim
authors.forename: Lilach
authors.initials: L
authors.lastname: Israeli-Shani
authors.forename: Esther
authors.initials: E
authors.lastname: Manor
authors.forename: Ruth
authors.initials: R
authors.lastname: Birk
authors.forename: Ruti
authors.initials: R
authors.lastname: Parvari
mesh_terms: D000328:Adult; D001483:Base Sequence; D002864:Chromogranins; D004247:DNA / Q000097:blood / Q000737:chemistry; D005260:Female; D005359:Fibrous Dysplasia, Polyostotic / Q000175:diagnosis / Q000235:genetics*; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D010375:Pedigree; D012333:RNA, Messenger / Q000032:analysis; D014430:Twins, Monozygotic / Q000235:genetics
chemical_list: D002864:Chromogranins; D012333:RNA, Messenger; D004247:DNA; C406732:GNAS protein, human; D019205:GTP-Binding Protein alpha Subunits, Gs