Increasing growth with raised circulating somatomedin but normal immunoassayable growth hormone

Two patients are described with elevation of circulating somatomedin A concentration but normal growth hormone levels. One,a young male, appeared clinically acromegalic; the other, a young female, was tall with kyphoscoliosis, and her appearance resembled Marfan's syndrome. In both patients plasma growth hormone concentration was suppressible by hyperglycaemia. It is suggested that their clinical syndromes resulted from excessive somatomedin activity.