title: Effect of the parental origin of the X-chromosome on the clinical features, associated complications, the two-year-response to growth hormone (rhGH) and the biochemical profile in patients with turner syndrome.
abstract: BACKGROUND
  It is possible that genes on the X chromosome are expressed differently depending of its parental origin. The objective of this study was to determine the influence of the parental origin of the X-chromosome on phenotypic variability, response to rhGH and on the biochemical profile of TS patients.
  
  
  METHODS
  This was a cross-sectional multicenter correlational study carried out over three years in six Latin-American university hospitals. Unrelated 45,X TS patients (n =  93; 18.3 ± 8.5 years )) were evaluated. A subgroup (n =  34) of the patients were prospectively treated with rhGH over two years. DNA profiles of patients and their mothers were compared to determine the parental origin of the retained X-chromosome through 10 polymorphic X-chromosome-STRs. The association with clinical features, biochemical profiles and anthropometric data at the beginning and after two years of rhGH treatment was determined.
  
  
  RESULTS
  Seventy two percent of patients retained the maternal X chromosome (Xm). A trend towards significance between maternal height and patients final height (p ≤ 0.07) in 45,Xm subjects was observed. There was no correlation between paternal height and patient height. No differences were detected between both groups in regard to dysmorphic features, classical malformations or increase in the height-SDS after rhGH. There were higher levels of triglycerides, total and LDL cholesterol in patients >20 years who retained the Xm.
  
  
  CONCLUSIONS
  The parental origin of the retained X chromosome may influence lipid metabolism in TS patients, but its effect on growth seems to be minimal. No parental-origin-effect on the phenotypic features, associated anomalies and on the growth response to rhGH was found in 45,X TS individuals.
authors.affiliation: Unidad de Endocrinología Pediátrica, Hospital de Clínicas Caracas, Caracas, Venezuela. lanesroberto@gmail.com.
authors.forename: Francisco
authors.initials: F
authors.lastname: Alvarez-Nava
authors.forename: Roberto
authors.initials: R
authors.lastname: Lanes
authors.forename: José Miguel
authors.initials: JM
authors.lastname: Quintero
authors.forename: Mirta
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authors.lastname: Miras
authors.forename: Hugo
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authors.lastname: Fideleff
authors.forename: Verónica
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authors.lastname: Mericq
authors.forename: Henry
authors.initials: H
authors.lastname: Marcano
authors.forename: William
authors.initials: W
authors.lastname: Zabala
authors.forename: Marisol
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authors.lastname: Soto
authors.forename: Tatiana
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authors.lastname: Pardo
authors.forename: Lisbeth
authors.initials: L
authors.lastname: Borjas
authors.forename: Joalice
authors.initials: J
authors.lastname: Villalobos
authors.forename: Peter
authors.initials: P
authors.lastname: Gunczler
authors.forename: Nancy
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authors.lastname: Unanue
authors.forename: Natalia
authors.initials: N
authors.lastname: Tkalenko
authors.forename: Adriana
authors.initials: A
authors.lastname: Boyanofsky
authors.forename: Liliana
authors.initials: L
authors.lastname: Silvano
authors.forename: Liliana
authors.initials: L
authors.lastname: Franchioni
authors.forename: Miriam
authors.initials: M
authors.lastname: Llano
authors.forename: Gabriel
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authors.lastname: Fideleff
authors.forename: Miriam
authors.initials: M
authors.lastname: Azaretzky
authors.forename: Martha
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authors.lastname: Suarez