Osteoarthritis is the most common of the degenerative joint diseases and it is a significant cause of disability among older people. We know that age, overweight and obesity, as well as a history of injury, are risk factors for osteoarthritis. But genetic factors are involved as well. Researchers in Germany have now uncovered a variant in a gene known as COX-2. We know that this gene is involved in the inflammatory process which appears to be involved in end-stage hip and knee osteoarthritis. The variant involves a change in the DNA of this gene from coding letter G to C. Note that the genetic code of DNA is ‘written’ in chemicals called four bases known as G, C, A and T for short and in gene variants, these letters are swapped and substituted in various places on the genome. Also, each person bears two copies – known as alleles – of each gene. One is inherited from the mother, one from the father.
