We found that the rare allele of four SNPs in four genes were more common than expected in individuals who had suffered CRPS-1 for more than a year; rs41289586 in ANO10, rs28360457 in P2RX7, rs1126930 in PRKAG1 and rs80308281 in SLC12A9. The gene discussed is SLC12A9; the disease is complex regional pain syndrome type 1.