SPONTANEOUS ADULT HEIGHT IN IDIOPATHIC SHORT STATURE

Two hundred and thirty-six patients with idiopathic short stature (ISS ) (184 m, 52 f) who presented at a mean age of 12.2 (range 2.8-17,5) y ears, a mean height of -2.16 standard deviation score (SDS), a mean ta rget height (THT) of -0.27 SDS (m = f), were reinvestigated at a mean age of 20.5 (range 18-24) years, 182 (142 m, 37 f) (67%) had reached n ormal adult height (AHT) while 54(39 m, 15 f) (23%) had not. However, only 23 (17 m, 6 f) did not reach a height within their familial targe t. Patients were subdivided into 2 groups according to deviation from familial height target: 60 (44 m, 16 f) were considered adequate for t heir families (group 1), while 176 (140 m, 39 f) were smaller (group 2 ). Children in group 1 were younger and bone age (BA) was less retarde d. Patients in group 1 reached their THT, this was not the case in gro up 2, Young age, low THT and low predicted adult height (PAH) at prese ntation were the factors associated with poor statural outcome, but AH T could not be predicted in individuals. In boys, PAH (Bayley-Pinneau) (0.0 SDS) exceeded AHT (-0.7 SDS), in girls, both were almost identic al(-0.79, -0.77 SDS). Since most children with ISS reach an AHT within the normal range, attempts to improve AHT by means of growth-promotin g therapies appear to be justified only in a minority of selected pati ents with ISS. Methods to improve the accuracy of individual height pr ognoses are needed.