The COL5A1 gene is associated with increased risk of anterior cruciate ligament ruptures in female participants.
BACKGROUND
Anterior cruciate ligament ruptures, especially to young female athletes, are a cause of major concern in the sports medicine fraternity. The major structural constituents of ligaments are collagens, specifically types I and V. Recently, the gene that encodes for the alpha1 chain of type I collagen (COL1A1) has been shown to be associated with an increased risk of cruciate ligament ruptures. The COL5A1 gene, which encodes for the alpha1 chain of type V collagen, has been shown to be associated with Achilles tendon injuries.


OBJECTIVE
The study was conducted to determine (1) if 2 sequence variants (BstUI and DpnII restriction fragment length polymorphisms [RFLPs]) within the COL5A1 gene are associated with an increased risk of anterior cruciate ligament ruptures, and (2) if there were any gender-specific positive associations between the 2 COL5A1 sequence variants and risk of anterior cruciate ligament ruptures.


METHODS
Case control study; Level of evidence, 3.


METHODS
A total of 129 white participants (38 women) with surgically diagnosed anterior cruciate ligament ruptures and 216 physically active control participants (84 women) without any history of ACL injury were included in this case-control genetic association study. All participants were genotyped for the COL5A1 BstUI and DpnII RFLPs.


RESULTS
There was a significant difference in the BstUI RFLP genotype frequency between the anterior cruciate ligament rupture and physically active control groups among the female participants, but not the male participants. The CC genotype in the female participants was significantly underrepresented in the anterior cruciate ligament rupture group compared with the controls (27.4% vs 5.6%; odds ratio = 6.6; 95% confidence interval, 1.5-29.7; P = .006). There were no differences in the DpnII RFLP genotype distributions between the anterior cruciate ligament rupture and physically active control groups.


CONCLUSIONS
The CC genotype of the COL5A1 BstUI RFLP was underrepresented in female participants with anterior cruciate ligament ruptures.


CONCLUSIONS
This is the first study to show that there is a specific genetic risk factor associated with risk of anterior cruciate ligament ruptures in female athletes.
Posthumus
Michael
M
Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
September
Alison V
AV
O'Cuinneagain
Dion
D
van der Merwe
Willem
W
Schwellnus
Martin P
MP
Collins
Malcolm
M
D000293:Adolescent; D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries; D016022:Case-Control Studies; D024062:Collagen Type V / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D007718:Knee Injuries / Q000235:genetics*; D008297:Male; D012150:Polymorphism, Restriction Fragment Length; D012307:Risk Factors; D012421:Rupture / Q000235:genetics; D012727:Sex Characteristics; D055815:Young Adult
C530725:COL5A1 protein, human; D024062:Collagen Type V