Objective: Anterior cruciate ligament (ACL) ruptures have been reported as the most severe injury sustained in sports. Although various intrinsic and extrinsic risk factors have been identified, the exact aetiology is not yet fully understood. Recently, the gene encoding for the α1 chain of type I collagen (COL1A1) has been shown to be associated with cruciate ligament ruptures and shoulder dislocations. The aim of this study was therefore to determine whether the functional Sp1 binding site polymorphism within intron 1 of the COL1A1 gene is associated, specifically with, ACL ruptures in an independent second population.
Methods: One hundred and seventeen Caucasian participants with surgically diagnosed ACL ruptures, as well as 130 Caucasian physically active controls (CON) without any history of previous ligament or tendon injuries were recruited for this case-control genetic association study. All participants were genotyped for the COL1A1 Sp1 binding site polymorphism (G/T; rs1800012).
Results: The rare TT genotype was significantly (p=0.031, OR=0.08, 95%CI <0.01 to 1.46) under-represented in the ACL group (0 out of 117, 0%), when compared to the CON group (6 out of 130, 4.6%).
Conclusion: The TT genotype of the COL1A1 Sp1 binding site polymorphism was significantly under-represented in South African participants with anterior cruciate ligament ruptures. It is therefore proposed that this sequence variant be the first specific genetic element to be included in multifactorial models developed to understand the aetiology and risk factors for ACL rupture.