Related Experiment Videos
Parkinson disease in twins: an etiologic study
C M Tanner1, R Ottman, S M Goldman
1The Parkinson's Institute, Sunnyvale, Calif 94089, USA. ctanner@parkinsonsinstitute.org
JAMA
|February 3, 1999
Summary
This study found that genetic factors play a minor role in typical Parkinson disease (PD) overall. However, genetics appear significant for early-onset PD diagnosed at or before age 50.
Area of Science:
- Neurology
- Genetics
- Epidemiology
Background:
- The etiology of Parkinson disease (PD) remains largely unknown.
- While genetic links exist in familial cases, the overall heritability of PD is not well-established.
Purpose of the Study:
- To investigate the role of genetic inheritance in Parkinson disease.
- To compare concordance rates between monozygotic (MZ) and dizygotic (DZ) twin pairs.
Main Methods:
- A twin study design was employed, comparing PD concordance rates in MZ and DZ twins.
- 19,842 white male twins from the WWII Veteran Twins Registry were screened for PD.
- Zygosity was determined, and PD diagnoses were confirmed using standard criteria.
Main Results:
- The overall pairwise concordance for PD was similar between MZ (0.155) and DZ (0.111) twins, suggesting limited genetic influence in typical PD.
- No significant genetic component was observed for PD cases diagnosed after age 50.
- In contrast, for PD diagnosed at or before age 50, MZ concordance was 1.0 compared to 0.167 in DZ twins, indicating a strong genetic role.
Conclusions:
- Overall concordance rates suggest that genetic factors are not a primary cause of typical Parkinson disease.
- Genetic inheritance appears to be a significant factor in early-onset Parkinson disease (onset ≤ 50 years).
- For late-onset Parkinson disease (onset > 50 years), genetic factors seem to play a minimal role.