Validation of growth charts for girls with Turner syndrome

Growth charts, which describe the natural course of growth in Turner syndrome (TS) patients, are commonly used in studies in lieu of control groups. While analysing data, various charts produce different final height estimations and height-gain predictions. The choice of an appropriate chart should be the first task when assessing effects of growth hormone treatment. The purpose of this study was to establish the most appropriate growth chart for the subsequent analysis of growth rate in the patients with TS observed initially for a short time without treatment in our clinic. We propose the criteria that a standardised chart should meet. The obtained height-standardised values (height standard deviation score -- Ht SDS) should represent normal distribution with a mean of 0 and standard deviation of 1; their initial mean value and mean change in these values during observation without treatment should not be different from 0. We studied 62 untreated girls with TS using three different growth charts. The values of Ht SDS based on the Lyon chart showed a significant difference from normal distribution (p < 0.05). Only the mean value of an initiaent from 0 (p = 0.088). The mean change of the Ht SDS value based on Lyon and Ranke charts during the follow-up period was not statistically different from 0 (p > 0.05), whereas the difference was statistically significant when the Wisniewski chart was used. Only the Ranke chart correctly characterised TS girls in our clinic. This analysis indicates the importance of careful selection of an appropriate growth chart for an observed population, before applying it to evaluate the effects of hormonal therapy.