Serum somatomedin A in Perthes' disease.

Serum somatomedin A, determined by radioreceptor assay in 47 children with Perthes' disease, was significantly reduced as compared to normal children of the same age. Nine children underwent the 1-Dopa tolerance tests to evoke growth hormone release; a normal response was found in eight. Patients with Perthes' disease tend to be short in stature with "disproportionate skeletal growth" of the limbs; growth is less in the distal than in the proximal extremities. The low serum levels of somatomedin A suggest some growth disturbance during the development of Perthes' disease.