[Parkinson's disease(s): recent insight into genetic factors]

In recent years, 5 genes have been identified that are unambiguously associated with genetic forms of Parkinson's disease. These genes probably explain less than 10% of all cases of Parkinson's disease. Clinically, these genetic forms can closely resemble idiopathic Parkinson's disease. Mutation analysis could be considered in cases involving an age at onset before 45 years, a positive family history or atypical presentations. However, the role of genetic testing in clinical practice remains to be established. Dysfunction of the ubiquitin-proteasome complex, abnormalities of the oxidative stress response and mitochondrial defects represent the three main disease mechanisms implicated in Parkinson's disease caused by these gene mutations. Further research is likely to contribute to the understanding and future treatment of idiopathic Parkinson's disease.