Parkinson's disease (PD) is the second most frequent neurodegenerative disorder after Alzheimer's disease. It causes motor dysfunctions, such as bradykinesia, resting tremor, rigidity and postural instability. Although PD appears to be sporadic in most cases, several causative genes and susceptibility factors have been identified that cause familial forms of the disease with Mendelian inheritance with autosomal dominant or autosomal recessive inheritance.