Variations in the serum concentration and urine excretion of alpha 2HS-glycoprotein, a bone-related protein, in normal individuals and in patients with osteogenesis imperfecta.

The concentration of alpha 2HS-glycoprotein was measured in the serum and urine of normal individuals and of patients with osteogenesis imperfecta. The serum concentration of alpha 2HS-glycoprotein was higher in normal children than in adults. In women values showed a progressive age-related decrease, from 632 mg/l at 21-30 years to 573 mg/l at 51-60 years. In men there was no such age-related variation, and values were higher than in women of comparable age; the mean value for men aged 20-60 years was 648 mg/l. Of 48 patients with osteogenesis imperfecta, 11 had an abnormally high concentration of alpha 2HS-glycoprotein in serum; the cause of this is not clear. In urine of 24 normal individuals the mean value of the ratio albumin: alpha 2HS-glycoprotein was 20 +/- 3; in serum the corresponding ratio was 70. Urine excretion of alpha 2HS-glycoprotein was lowest in female children (132 +/- 29 micrograms/24 h) and highest in male adults (592 +/- 91 micrograms/24 h); values in patients with osteogenesis imperfecta did not differ from normal.