title: Molecular analysis in Turner syndrome.
abstract: OBJECTIVE
  The frequency of Y-chromosome material is high in Turner syndrome (TS), but the ocurrence of gonadoblastoma seems to be low. We performed a study to evaluate whether DNA analysis might be a useful tool in the evaluation of patients with TS.
  
  
  METHODS
  Unrelated patients with TS (n = 52) of Venezuelan mestizo ethnic origin were diagnosed by cytogenetic analysis as having TS.
  
  
  METHODS
  Clinical assessment, karyotyping, endocrine evaluation, fluorescence in situ hybridization, and polymerase reaction chain analysis of the Y-chromosome loci.
  
  
  RESULTS
  We found that 7.69% (4 of 52) patients with TS had Y-chromosome material. A low occurrence of gonadoblastoma was also found (2 of 52 [3.85%]). Two patients showed a 45,X/46,XY karyotype, and gonadoblastoma in the gonadal biopsy specimen was not found. Two patients had no Y chromosome on initial karyotype; they were positive on lymphocyte DNA to Y-sequences specific. Both patients (45,X) had bilateral gonadoblastoma. The four patients with Y-chromosome material in peripheral blood lymphocytes had Y-chromosome sequences on gonadal DNA. Fluorescence in situ hybridization confirmed their Y-chromosome origin.
  
  
  CONCLUSIONS
  Our results suggest that the detection of Y-chromosome material should be carried out in all patients with TS and not be limited to patients with TS with cytogenetically identifiable Y chromosome and/or virilization.
authors.affiliation: Unidad de Genética Médica, Facultad de Medicina, Universidad del Zulia, Maracaibo, Venezuela. falvareznava@yahoo.com
authors.forename: Francisco
authors.initials: F
authors.lastname: ALvarez-Nava
authors.forename: Marisol
authors.initials: M
authors.lastname: Soto
authors.forename: María A
authors.initials: MA
authors.lastname: Sánchez
authors.forename: Erika
authors.initials: E
authors.lastname: Fernández
authors.forename: Roberto
authors.initials: R
authors.lastname: Lanes
mesh_terms: D002648:Child; D041322:Chromosomes, Human, Y / Q000235:genetics*; D020732:Cytogenetic Analysis; D005260:Female; D018238:Gonadoblastoma / Q000150:complications / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D009030:Mosaicism; D010051:Ovarian Neoplasms / Q000150:complications / Q000235:genetics; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014424:Turner Syndrome / Q000150:complications / Q000175:diagnosis / Q000235:genetics*