Adult height in girls with Turner syndrome treated from before 6 years of age with a fixed per kilogram GH 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 per week. Patients and design: After a 6-month pretreatment assessment all patients were measured 6-monthly under therapy to assess height SDS (H-SDS) and height velocity (HV) until AH achievement. Results: Following initial acceleration, HV declined after the first 4 years of therapy. At the end of the sixth 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 Sempe standards) was close to those recorded at the 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 year, but the response waned after 6 years of treatment.