C9ORF72 and parkinsonism: Weak link, innocent bystander, or central player in neurodegeneration?

- C9ORF72-associated diseases may vary from ALS-FTD complex to movement disorders.
- We describe an atypical DOPA-responsive parkinsonism carrying C9orf72 expansion.
- Penetrance, genotype-phenotype correlations and DOPA-responsiveness are discussed.