Parkinson’s disease is the second most frequent neurodegenerative disorder of the central nervous system: it affects about 4.5 million people over 50 years of age.

Parkinson’s disease (PD was originally described in 1817 by James Parkinson in the classic ‘‘Essay on the Shaking Palsy’’. All the cardinal signs of PD relate to motor dysfunction and include resting tremor, bradykinesia, rigidity and postural reflex impairment. The age of onset is in the seventh decade and symptoms are typically unilateral.

The genetic background of Parkinson’s disease remained unknown until the past 20 years, but recent evidence revealed the presence of important gene mutations and genetic loci involved in the disease etiology.

The identification of the genetic causes of these disorders represents a fundamental step to understand the molecular mechanisms and might lead in a future to a specific therapy for these diseases.