Growth of Children with Hypochondroplasia Treated with Growth Hormone for Two Years

Choi, Bo Ram; Song, Moon Young; Suh, Byung Kyu; Lee, Byung Churl

Abstract

PURPOSE
Hypochondroplasia is a skeletal dysplasia characterized by poor childhood growth and an inadequate pubertal growth spurt. Final height attainment of hypochondroplasia has been reported to range between 120 and 152cm. Increased availability of growth hormone with the introduction of recombinant human growth hormone has allowed for clinical trials in a number of growth hormone sufficient children with growth problems. The purpose of this study was to assess the growth promoting effect of human growth hormone in children with hypochondroplasia.
METHODS
Five patients with hypochondroplasia diagnosed by clinical and radiological findings between 1993 and 1997 at our hospital was aged 3 and 1/2 -11 and 1/2 years. Each patients continuously received human growth hormone 0.6-0.7U/Kg/week, intramuscularly or subcutaneously in 6-7 divided dose for 2 years. Standard auxologic assessment was carried out every 3 month interval in the first year after commencement of therapy and then same assessment was 6 monthly. Bone age was assessed 6 monthly using Gleurich-Pyle method.
RESULTS
Mean height velocity of pretreatment and year 1 and 2 of GH treatment were 3.9+/-0.7, 6.5+/-1.8 and 5.7+/-1.5cm/year, respectively. Mean height standard deviation score for chronological age of pretreatment and year 1 and 2 of GH treatment were -2.7+/-0.3, -2.4+/-0.3 and -2.2+/-0.4, respectively. The increase in the height velocity diminishes over the subsequent year. The increment of bone age after GH treatment were same as the increments of chronological age.
CONCLUSION
Short-term GH therapy increases the height velocity of children with hypochondroplasia, but the effect of GH therapy on final height remains unknown.