Familial Parkinson's disease: a community-based study.

Area of Science:

• Neurology
• Genetics
• Epidemiology

Background:

• Genetic factors are implicated in Parkinson's disease (PD) pathogenesis.
• The extent of familial aggregation in PD remains a subject of debate.

Purpose of the Study:

• To determine the frequency of a positive family history of Parkinson's disease (PD) in a patient cohort.
• To compare PD family history rates against two control groups.

Main Methods:

• A cohort of 245 Parkinson's disease (PD) patients underwent neurological examination and semi-structured interviews.
• Family history of PD and dementia was assessed in patients and control groups.

Main Results:

• A positive family history of Parkinson's disease (PD) was identified in 21.6% of patients.
• The frequency of PD in families was 3- to 4-fold higher compared to control groups (P < 0.001).
• No significant differences were observed in age at onset or dementia frequency within families.

Conclusions:

• This community-based study supports a 3- to 4-fold increased risk of Parkinson's disease (PD) in affected families.
• Familial aggregation of Parkinson's disease (PD) appears independent of the proband's age at onset.