Achondroplastic dwarfism. Effects of treatment with human growth hormone.

Two male patients with achondroplastic dwarfism aged 7-5/12 and 14(1/2) years were treated with human growth hormone 5 mg daily. Both showed nitrogen retention on balance studies, the older second patient to a marked degree. In the younger patient, height increased from 95.4 to 106.3 cm on hgh 5 mg daily alone for 14 out of 24 months. The rate of growth approximately doubled during the first two treatment periods as compared with the pre-treatment rate. In the second older patient hgh was administered 5 mg daily intramuscularly for 21 out of 33 months. Growth from 129.6 cm to 137.8 cm occurred with the rate increasing following the addition of Na-1-thyroxine to the routine. This increased growth rate occurred during the post-puberty deceleration phase. Bone ages, interpreted from changes in the phalanges and metacarpals, increased from 4(1/2) to 6 years during 16 months in Case 1, and from 13(1/2) to 18 years in 33 months in Case 2. Transient adolescent gynecomastia appeared in Case 2. No local or general toxic effects were noted. These results are suggestive, but whether or not the eventual height of an achondroplastic dwarf can be significantly altered must await further studies.