Genetic predisposition for osteoporosis

Patients with osteoporosis have reduced bone mass, a deterioration of bone tissue and an increased risk of fractures. Several genes regulating bone mineral density, geometry and quality have been implicated, but the genetic mechanisms of osteoporosis are still unknown. In the April Journal of Clinical Investigation, Val Mann and colleagues from the Rowett Research Institute, Aberdeen describe the mechanism by which the COL1A1 gene is involved in the predisposition to osteoporosis.

COL1A1 encodes the α1(1) protein chain of type I collagen. Mann et al performed a meta-analysis of 16 studies and confirmed that a polymorphism affecting a binding site for the transcription factor Sp1 in the COL1A1 gene is associated with increased risk of osteoporotic fractures. In addition, using gel shift assays they showed that collagen produced from osteoblasts of "Ss" heterozygotes had an increased ratio of α1(I) protein relative to α2(I). The strength of bone derived from...