Becker et al. (2011), reported that carriers of the minor allele C in rs622342 were prescribed a higher dose of levodopa, an anti-Parkinson drug also transported by OCT1. In contrast with rs72552763 where a 3 bp deletion occurs, in rs622342 an intronic region base change takes place, which might entail reduced-function transporter, SLC22A1 expression changes, or linkage imbalance respect to a functional SNP. According to Figure 1B, the mechanism could be a decreased expression of SLC22A1, since the presence of minor allele C involves a shorter HbA1c non-control timelapse. Here, SLC22A1 is linked to Parkinsonism.