title: COL1A1 Sp1 variation and bone phenotypes in an Italian population.
abstract: BACKGROUND
  Osteoporosis is the most common metabolic bone disorder of the elderly, affecting the normal bone turnover with an increased bone resorption and subsequent higher risk of fragility fractures. Collagen type 1 is the most represented protein in bone matrix. A genetic variation (Sp1) in intron 1 of COL1A1 gene has been associated to modulation of expression of the alpha 1 chain of collagen type 1 and it is considered a candidate polymorphism for predisposition to osteoporosis status and fragility fractures. Association studies, in ethnically different populations, are needed to strongly confirm the role of this polymorphism in bone metabolism.
  
  
  METHODS
  We enrolled over 2,000 Italian individuals and studied their bone mineral density (BMD) and fractures in relation to age, sex and body mass index (BMI). Moreover, we analyzed the distribution of Sp1 polymorphism in these individuals and associated it to normal bone status, osteopenic condition or osteoporosis diagnosis, BMD and the presence of low-trauma fractures.
  
  
  RESULTS
  The most rare ss genotype showed a trend for osteoporosis diagnosis with respect to both normal and osteopenic status. The same genotype resulted to be associated to lower values of BMD both at spine and femur sites. No association was found with fractures.
  
  
  CONCLUSIONS
  In conclusion the presence of the homozygote ss genotype seemed to predispose to osteoporosis diagnosis and to be more frequent in subjects with lower spine and femur BMD values.
authors.affiliation: Metabolic Bone Unit, Department of Surgery and Translational Medicine, University of Florence, Florence, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Marini
authors.forename: Simone
authors.initials: S
authors.lastname: Parri
authors.forename: Laura
authors.initials: L
authors.lastname: Masi
authors.forename: Simone
authors.initials: S
authors.lastname: Ciuffi
authors.forename: Andrea
authors.initials: A
authors.lastname: Guazzini
authors.forename: Sergio
authors.initials: S
authors.lastname: Fabbri
authors.forename: Ettore
authors.initials: E
authors.lastname: Luzi
authors.forename: Luisella
authors.initials: L
authors.lastname: Cianferotti
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Brandi
keywords: Sp1 polymorphism; bone mineral density; collagen type 1; fragility fracture risk; osteoporosis; osteoporosis prevention