A regression method including chronological and bone age for predicting final height in Turner's syndrome, with a comparison of existing methods

Abstract

A total of 235 measurement points of 57 Dutch women with Turner's syndrome (TS), including women with spontaneous menarche and oestrogen treatment, served to develop a new Turner-specific final height (FH) prediction method (PTS). Analogous to the Tanner and Whitehouse mark 2 method (TW) for normal children, smoothed regression coefficients are tabulated for PTS for height (H), chronological age (CA) and bone age (BA), both TW RUS and Greulich and Pyle (GP). Comparison between all methods on 40 measurement points of 21 Danish TS women showed small mean prediction errors (predicted minus observed FH) and corresponding standard deviation (ESD) of both PTSRUS and PTSGP, in particular at the "younger" ages. Comparison between existing methods on the Dutch data indicated a tendency to overpredict FH. Before the CA of 9 years the mean prediction errors of the Bayley and Pinneau and TW methods were markedly higher compared with the other methods. Overall, the simplest methods--projected height (PAH) and its modification (mPAH)--were remarkably good at most ages. Although the validity of PTSRUS and PTSGP remains to be tested below the age of 6 years, both gave small mean prediction errors and a high accuracy. FH prediction in TS is important in the consideration of growth-promoting therapy or in the evaluation of its effects.