LRRK2 mutations in Parkinson disease

To determine the frequency of LRRK2 mutations in idiopathic Parkinson disease (PD), the authors studied 786 PD probands, 32 affected siblings, 1,044 unaffected siblings, and 278 unrelated controls. The authors designed allelic discrimination assays for nine LRRK2 mutations and identified these in six probands with PD, one affected sibling, one unaffected sibling, and one unrelated control. Thus LRRK2 mutations only rarely cause idiopathic PD.