Increase in Near-Final Height in Short Non-Growth Hormone Deficient Children Treated with Growth Hormone

The Genentech Study Group has treated patients with severe short stature (height <-2 SD score (SDS) not due to classically defined GH deficiency with up to seven years of GH treatment (0.3mg/kg/wk). Of the initial 121 patients, 33 have achieved near final height, with bone age (BA) ≥16 years for boys and ≥14 years for girls. At this bone age greater than 98% of adult height has been achieved. The mean difference between the first available pretreatment predicted adult height (PAH) and the PAH at near final height (Δ PAH) was 4.0cm for the boys and 8.1cm for the girls. We compared these changes in PAH achieved with GH treatment of these short non-GH deficient patients with the changes seen in 33 untreated normal children from the Fels Longitudinal Growth Study whose height was below -1 SDS for age, and to 19 historical controls followed in our clinics whose height was below -2 SDS for age at presentations who were not treated with GH. The differences in Δ PAH achieved by the GH treated patients compared to the -1 SDS controls were 5.7cm for boys and 4.5cm for girls. When compared to the <-2 SDS controls the differences in PAH were 8.2cm for boys and 7.7cm for girls. We conclude that GH treatment of patients with marked short stature does result in an increase in their mean final height. However, these patients did not achieve their mean mid-parental target height.