However, in 2009 and following, PD genome-wide association studies (GWAS) identified common genetic variance at and near the LRRK2 locus as a risk factor for PD9,10, pointing to the possibility that LRRK2 dysfunction may be involved in PD pathomechanisms in patients who do not harbour a missense mutation. The gene discussed is LRRK2; the disease is Parkinson disease.