Trace elements and transport proteins in serum of children with Down syndrome and of healthy siblings living in the same environment.

Twenty-two children with Down syndrome (DS), 8 boys and 14 girls, in the age range 5 to 15 years were investigated and compared with a control group of 22 healthy children, 9 boys and 13 girls of the same age group, 9 of them being siblings of patients with DS. Concentrations of iron, copper and zinc in serum were determined by atomic absorption spectrophotometry and serum proteins were quantitated by the radial immunodiffusion technique. The subjects with DS had significantly lower mean serum iron (P less than 0.01) and zinc (P less than 0.001) than the healthy controls. Four DS children had serum iron values that fell below the normal range. In more than 60 per cent of the DS patients the zinc concentration fell below the normal range. The children with DS had significantly higher mean serum copper (P less than 0.05) but lower serum iron (P less than 0.05) and zinc (P less than 0.05) levels than their healthy siblings living in the same family at the time of examination. The DS patients as a group had higher levels of caeruloplasmin (P less than 0.01), haptoglobin (P less than 0.001), orosomucoid (P less than 0.001) and alpha 2-macroglobulin (P less than 0.001) than the healthy controls and compared with their siblings. Except for prealbumin and retinol-binding protein (RBP), no age-related variation in the serum concentrations of the studied proteins was found in the DS patients. Albumin, prealbumin, RBP and transferrin levels were similar in the two study groups.(ABSTRACT TRUNCATED AT 250 WORDS)