Parental Origin of the X-Chromosome Does Not Influence Growth Hormone Treatment Effect in Turner Syndrome

Abstract

Abstract Context: The parental origin of the intact X-chromosome has been reported to affect phenotype and response to GH treatment in Turner syndrome (TS). Objective: Our objective was to evaluate the influence of the parental origin of the X-chromosome on body growth and GH treatment effect in TS. Design and Setting: We conducted a population-based cohort study of TS patients previously treated with GH. Participants: Participants included patients with a nonmosaic 45,X karyotype; 556 women were identified as eligible, 233 (49%) of whom participated, together with their mothers. Data were analyzed for 180 of these patients. Main Outcome Measures: We performed fluorescence in situ hybridization analysis to exclude mosaicism and microsatellite analysis of nine polymorphic markers in DNA from the patients and their mothers. The influence on growth and effect of GH were analyzed by univariate and multivariate methods. Results: The X-chromosome was of paternal origin (Xpat) in 52 (29%) of 180 and of maternal origin (Xmat) in 128 (71%) of 180 patients. Height gain from the start of GH treatment to adult height was similar in Xmat and Xpat patients (+2.1 ± 0.9 vs. +2.2 ± 0.8 TS sd score, P = 0.45). The lack of influence of parental origin of the X-chromosome was confirmed in multivariate analysis. Parental origin of the X-chromosome also had no effect on the other growth characteristics studied, including growth velocity during the first year on GH treatment. Patient height was correlated with the heights of both parents and was not influenced by the parental origin of the X-chromosome. Conclusion: In this, the largest such study carried out to date, the parental origin of the X-chromosome did not alter the effect of GH treatment or affect any other features of growth in TS.