Parkinson disease 2

=Parkinson Disease 2 = Parkinson Disease 2 (PD2) is a rare genetic form of Parkinson's disease, characterized by early-onset parkinsonism. It is associated with mutations in the PARK2 gene, which encodes the protein parkin. This condition is part of a group of disorders known as Parkinsonism, which share similar symptoms such as tremors, rigidity, and bradykinesia.

Genetics

PD2 is caused by mutations in the PARK2 gene located on chromosome 6q25.2-q27. The PARK2 gene provides instructions for making a protein called parkin, which plays a crucial role in the ubiquitin-proteasome system, a pathway that helps degrade and recycle damaged or unneeded proteins. Mutations in this gene lead to the accumulation of defective proteins, contributing to the death of dopaminergic neurons in the substantia nigra, a hallmark of Parkinson's disease.

Clinical Features

The clinical presentation of PD2 is similar to that of idiopathic Parkinson's disease but typically occurs at a younger age, often before the age of 40. Common symptoms include:

• Resting tremor
• Muscle rigidity
• Bradykinesia (slowness of movement)
• Postural instability

Unlike typical Parkinson's disease, PD2 may have a slower progression and a better response to dopaminergic therapies.

Diagnosis

Diagnosis of PD2 involves a combination of clinical evaluation and genetic testing. A neurologist will assess the patient's symptoms and family history, and genetic testing can confirm the presence of mutations in the PARK2 gene. Genetic counseling is often recommended for affected individuals and their families.

Treatment

There is currently no cure for PD2, but treatment focuses on managing symptoms. Common treatments include:

• Levodopa and other dopaminergic medications to improve motor symptoms
• Physical therapy to maintain mobility and function
• Occupational therapy to assist with daily activities

Research and Future Directions

Research into PD2 is ongoing, with studies focusing on understanding the molecular mechanisms of parkin dysfunction and developing potential therapies. Gene therapy and neuroprotective strategies are areas of active investigation.

See Also

• Parkinson's disease
• Genetic disorders
• Neurodegenerative diseases
• Klein, C., & Westenberger, A. (2012). Genetics of Parkinson's disease. Cold Spring Harbor Perspectives in Medicine, 2(1), a008888.
• Kitada, T., et al. (1998). Mutations in the parkin gene cause autosomal recessive juvenile parkinsonism. Nature, 392(6676), 605-608.

NIH genetic and rare disease info

• NIH info on Parkinson disease 2

Parkinson disease 2 is a rare disease.