Parkinson disease (PD) is a progressive neurodegenerative disorder mainly affecting the motor system. PD is characterized by tremor, rigidity, bradykinesia, poor balance, and difficulty with walking. Non-motor findings include insomnia, depression, anxiety, behavioral problems, at a later stage of the disease psychosis and dementia may occur.
PD is most commonly a non-Mendelian disorder resulting from the effects of multiple genes as well as environmental risk factors. Mendelian forms of PD are inherited in an autosomal dominant, autosomal recessive, or, rarely, X-linked manner. The most common sporadic form of PD manifests around age 60, however, young-onset and juvenile-onset are seen.
Indications for genetic testing:
1. Confirmation of clinical diagnosis
2. Determination of differential diagnosis
3. Genetic counseling
Davie CA. A review of Parkinson’s disease. 2008. Br. Med. Bull. 86 (1): 109–27.
Farlow J et al. Parkinson Disease Overview. GeneReviews® 2004 May 25 (Updated 2014 Feb 27).