It is also important to note that the most important LRRK2 PD risk allele G2019S did not reach statistical significance in one of the CD studies (101): “The LRRK2 N2081D CD risk allele is located in the same kinase domain as G2019S, a mutation that is the major genetic cause of familial and sporadic PD [...]. Here, LRRK2 is linked to Parkinson disease.