SCN9A and osteoarthritis: The minor allele of the NaV1.7 R1150W variant, which is known to produce hyperexcitability in DRG neurons [26], has been associated with increased pain scores in a number of acquired pain syndromes (osteoarthritis, compressive radiculopathies, traumatic limb amputation), suggesting that environmental factors may, at least in some individuals, act as triggers or increase risk of developing pain [27].