Growth of children with hypochondroplasia treated with growth hormone for up to three years.

Hypochondroplasia is a skeletal dysplasia characterised by poor childhood growth and an inadequate pubertal growth spurt. 31 children with a radiological diagnosis of hypochondroplasia have been treated for up to 3 years with recombinant human growth hormone, mean dose 17.9 U/m2/week as daily subcutaneous injections. Mean pre-treatment height velocity standard deviation score (SDS) was -0.51; this increased to +1.58 after 1 year of treatment. This improvement diminishes over the next 2 years. The effect on final height remains unknown. There was a considerable variation in clinical response within the group treated.