Risk and recovery rate
Meniscus tear is probably the most common knee injury, often happens during sport activity.
The meniscus is a cartilage pad in the knee joint that serves as a shock absorber between the thighbone and shinbone.
Studies have found that meniscus-injured individuals tend to carry a certain genetic variant. This variant is also associated with time to recover after operation.
Cartilage weakens and wears thin over time. Aged, worn tissue is more prone to tears. However, sudden meniscus tears happen in all age groups, often during sports. Regardless of age, meniscus tear is the most common knee injury.
Genetic variants of genes involved with maintenance, development and repair of bones and cartilage were found associated with occurrence of meniscus injury. A genetic variant in the GDF-5 is the leading genetic risk factor for such injuries.
Gene: GROWTH/DIFFERENTIATION FACTOR 5 (GDF5)
Genomic coordinates (GRCh38): 20:35,433,346-35,454,745
GDF-5 is a growth factor involved in bone and cartilage formation. It regulates differentiation of chondrocytes, the cells that produce and maintain the cartilage matrix. GDF-5 is also required to prevent excessive muscle loss upon denervation (loss of nervous supply).
The central role of the GDF-5 gene in maintaining healthy cartilage is evident. Studies have found that the T allele is significantly over-represented in meniscus-injured individuals, compared with uninjured individuals.
The T variant is also associated with slower operation recovery time. C allele carriers have been shown to have enhanced tendon repair capacity and are at reduced risk for injury in the first place.