Parkinson is the second most common neurodegenerative disease after Alzheimers. About 1 percent of people over the age of 65 and 3 percent of people over the age of 75 are affected by the disease. The mutation is the most common cause of Parkinson's disease identified to date. LRRK2, a genetic mutation, was recently found linked to about 5 percent of inherited cases of Parkinson's disease. By high-resolution recombination mapping and candidate gene sequencing in 46 families, 6 disease-segregating mutations (5 missense and 1 putative splice site mutation). It may be central to the pathogenesis of several major neurodegenerative disorders associated with parkinsonism. LRRK2 belongs to the ROCO protein family and includes a protein kinase domain of the MAPKKK class and several other major functional domains.