title: Type I collagen alpha1 Sp1 polymorphism and the risk of cruciate ligament ruptures or shoulder dislocations.
abstract: BACKGROUND
  Cruciate ligament ruptures and shoulder dislocations are often caused by trauma, but predisposing intrinsic factors might also influence the risk. These injuries are more common in those with a previously injured sibling, an observation that might indicate a genetic predisposition. It is well known that polymorphisms in the collagen I gene are associated not only with osteoporosis and osteoporotic fracture risk, but also with osteoarthritis.
  
  
  OBJECTIVE
  Because collagen I is abundant in ligaments and tendons, the authors hypothesized that collagen I alpha1 Sp1 polymorphism also was related to the occurrence of cruciate ligament ruptures and shoulder dislocations.
  
  
  METHODS
  Case-control study; Level of evidence, 3.
  
  
  METHODS
  A total of 358 patients and 325 randomly selected population-based female controls were included in the study. Of the cases, 233 had a cruciate ligament rupture and 126 had had a shoulder dislocation. Age-adjusted odds ratios (ORs) with 95% confidence intervals (CIs) estimated by unconditional logistic regression were used as measures of association.
  
  
  RESULTS
  Compared with the homozygous SS category, the heterozygous participants displayed a similar risk (OR, 1.06; 95% CI, 0.76-1.49), whereas the ss genotype was underrepresented in the injured population compared with the controls (OR, 0.15; 95% CI, 0.03-0.68). This latter estimate was similar for both cruciate ligament ruptures and shoulder dislocations, and was furthermore not modified by general joint laxity.
  
  
  CONCLUSIONS
  The authors found a substantially decreased risk of these injuries associated with collagen type I alpha1 Sp1 polymorphism. The study might encourage other investigators to consider further research in the area of genes and soft tissue injuries.
authors.affiliation: Department of Surgical Sciences, Section of Orthopedics, University Hospital, Uppsala, Sweden. m_shwan@hotmail.com
authors.forename: Shwan
authors.initials: S
authors.lastname: Khoschnau
authors.forename: Håkan
authors.initials: H
authors.lastname: Melhus
authors.forename: Annica
authors.initials: A
authors.lastname: Jacobson
authors.forename: Hans
authors.initials: H
authors.lastname: Rahme
authors.forename: Henrik
authors.initials: H
authors.lastname: Bengtsson
authors.forename: Eva
authors.initials: E
authors.lastname: Ribom
authors.forename: Elin
authors.initials: E
authors.lastname: Grundberg
authors.forename: Hans
authors.initials: H
authors.lastname: Mallmin
authors.forename: Karl
authors.initials: K
authors.lastname: Michaëlsson
mesh_terms: D000293:Adolescent; D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries; D016022:Case-Control Studies; D024042:Collagen Type I / Q000235:genetics*; D000090602:Collagen Type I, alpha 1 Chain; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D016119:Posterior Cruciate Ligament / Q000293:injuries*; D012307:Risk Factors; D012783:Shoulder Dislocation / Q000235:genetics*; D017695:Soft Tissue Injuries / Q000235:genetics*; D055815:Young Adult
chemical_list: D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain