PEDICTION OF ADULT HEIGHT IN TURNER SYNDROME

Abstract

Predictions of adult height in girls with Turner Syndrome using established methods, projected height (PROJ), predicted height (PRED), and index of potential height (IPH), were compared to a novel method (KIGS):KIGS (as ht SDS) = ht SDS (using Ranke standards) - BA SDS for CA. BA SDS for CA was calculated from Greulich and Pyle BAs of 640 untreated girls with Turner Syndrome entered into the KabiPharmacia International Growth Study. Adult height predictions for 245 girls at onset of GH treatment (mean ± SD) were 145.5 cm ± 6.0 (PROJ), 144.9 cm ± 6.4 (PRED), 153.7 cm ± 7.2 (IPH), and 143.5 cm ± 6.4 (KIGS). 26 girls treated for 3 years with growth hormone alone had increases in height prediction of 8.7 cm ± 4.3 (PROJ), 5.6 cm ± 5.1 (PRED), 7.2 cm ± 6.0 (IPH), and 3.3 cm ± 6.4 (KIGS). Height predictions for 15 girls treated with combinations of growth hormone, oestrogen and oxandrolone were then compared to their own achieved adult heights: at 2 years into treatment, PROJ, PRED, and IPH already overestimated adult height by 1.8 cm ± 2.5, 2.5 cm ± 1.3, and 13.8 cm ± 1.6, respectively, and KIGS underpredieted by 2.5 ± 1.5 cm. We conclude that the established methods, especially IPH, tend to overpredict adult height in Turner Syndrome, and that the KIGS method is more conservative.