SCN9A and Pain: For example, SCN9A variants are implicated in more common neuropathic pain disorders such as idiopathic small fibre neuropathy12 and painful diabetic neuropathy.13 The SCN9A NM_002977.3:c.3448C>T, p.Arg1150Trp variant modulates risk and severity of pain across different chronic pain disorders.14 An environmental trigger that interacts with genes may cause neuropathic pain as some variants are common in the general population.