Can being genetically tested for the scn9a gene show a link to primary erythromelalgia?

Perhaps: This is a complicated area as multiple mutations of this gene have been described and associated with primary erythermalgia erythromelalgia (pe). Erythromelalgia is found in pts with myeloproliferative diseases and elevated platelet counts, though the symptoms are similar. If there is a familial incidence of pe, genetic testing could be done. Not clear about using it as a screening test.