The specific role of KCNQ1 gene in RA and PD pathogenesis has not been completely defined: the associated SNP is located in intron 15 of the KCNQ1 gene on chromosome 11p 15.5, encoding the pore-forming α subunit of a voltage-gated K+ channel, crucial for the repolarization phase in the cardiac muscle. This evidence concerns the gene KCNQ1 and rheumatoid arthritis.