Adult height of girls with Turner syndrome treated from before six years of age with a fixed per kg growth hormone dose.

OBJECTIVE: to evaluate adult height (AH) in 25 girls with Turner Syndrome (TS), who were treated from before 6 years of age for 10.0 ± 1.7 years with a fixed GH dose of 0.33 mg/kg/week. PATIENTS AND DESIGN: after a 6-month pretreatment assessment all patients were measured 6-monthly under therapy to assess height standard deviation score (H-SDS) and H velocity (HV) until AH achievement. RESULTS: following initial acceleration, HV declined after the first 4 years of therapy. At the end of the 6th year of therapy H-SDS gain was 1.9 ± 1.1. Thereafter, H-SDS gain from baseline decreased, becoming 0.9 ± 0.9 SDS at AH achievement. Bone maturation velocity did not significantly change throughout the prepubertal period. According to Lyon standards for TS, mean AH-SDS was significantly higher than pretreatment H-SDS (p < 0.0001), with a mean H-SDS change of 0.9 ± 0.9. However, the prevalence of patients with AH <-2 SDS (according to Sempé standards) was close to that recorded at start of therapy (16/25 vs 18/25). No significant differences in terms of AH were found between patients with either X monosomy or X-chromosomal abnormalities and between girls with either spontaneous or induced puberty. CONCLUSIONS: we infer that the therapeutic regimen adopted in this prospective study is sufficient to induce a significant growth acceleration during the first years, but the response waned after 6 years of treatment.