Total body bone mineral and tartrate-resistant acid phosphatase levels in type I and III osteogenesis imperfecta.

Serum tartrate-resistant acid phosphatase (TRAP) and total body bone mineral content (TBBM) were determined in a group of 16 children with osteogenesis imperfecta (OI) aged 5-14 years, 9 of whom suffered from type I and 7 from type III OI. TRAP and TBBM were also determined in a group of 26 normal children of a similar age range. TRAP levels were reduced in the type I and III OI groups (p less than 0.001). TBBM levels were lower in type I OI than in type III (p less than 0.005), and both OI groups showed reduced levels compared to the controls (p less than 0.001). The control group subjects showed a significant correlation between TRAP and TBBM (r = -0.62; p less than 0.001) which was not observed in the OI groups. Since TRAP is a biological marker of bone turnover, the results suggest that bone turnover is reduced in OI.