From Yeast to Therapeutic?: Yeast has shown some promise as a model system to generate lead compounds that could have therapeutic potential for the cellular problems associated with neurodegenerative diseases. Along these lines, Tardiff et al. (p. 979 , published online 24 October) and Chung et al. (p. 983 , published online 24 October) describe the results of multiple screens in yeast that lead to the identification of a potential therapeutic compound to combat the cytotoxic affect of α-synuclein accumulation. The compound was able to reverse the pathological hallmarks of Parkinson's disease in cultured neurons derived from patients with α-synuclein–induced Parkinson's disease dementia.

Elucidating the risk of Parkinson's disease: High expression of the α-synuclein gene ( SNCA ) is a risk factor for Parkinson's disease (PD), but certain drugs may mitigate this risk. Mittal et al. ran a small-molecule screen to identify compounds that regulate levels of SNCA expression and found that several β2-adrenoreceptor (β2AR) agonists reduced them (see the Perspective by Snyder). These compounds modulated epigenetic marks at the SNCA gene, effectively suppressing SNCA transcription. The authors looked at the pharmaceutical history of more than 4 million Norwegians over an 11-year period and found a reduced risk of PD among those that were taking one of the β2AR agonists for other medical problems. Science , this issue p. 891 ; see also p. 869

Importance Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common cause of genetic Parkinson disease (PD) known to date. The clinical features of manifestingLRRK2mutation carriers are generally indistinguishable from those of patients with sporadic PD. However, some PD cases associated withLRRK2mutations lack Lewy bodies (LBs), a neuropathological hallmark of PD. We investigated whether the presence or absence of LBs correlates with different clinical features inLRRK2-related PD. Observations We describe genetic, clinical, and neuropathological findings of 37 cases ofLRRK2-related PD including 33 published and 4 unpublished cases through October 2013. Among the different mutations, theLRRK2p.G2019S mutation was most frequently associated with LB pathology. Nonmotor features of cognitive impairment/dementia, anxiety, and orthostatic hypotension were correlated with the presence of LBs. In contrast, a primarily motor phenotype was associated with a lack of LBs. Conclusions and Relevance To our knowledge, this is the first report of clinicopathological correlations in a series ofLRRK2-related PD cases. Findings from this selected group of patients with PD demonstrated that parkinsonian motor features can occur in the absence of LBs. However, LB pathology inLRRK2-related PD may be a marker for a broader parkinsonian symptom complex including cognitive impairment.

Background: The “Lister family complex,” an extensive Swedish family with autosomal dominant Parkinson disease, was first described by Henry Mjönes in 1949. On the basis of clinical, molecular, and genealogic findings on a Swedish and an American family branch, we provide genetic evidence that explains the parkinsonism in this extended pedigree. Methods: Clinical methods included a detailed neurologic exam of the proband of the Swedish family branch, MRI, and ([123]I)–beta–CIT SPECT imaging. Genomic analysis included α-synuclein sequencing, SNCA real-time PCR dosage, chromosome 4q21 microsatellite analysis, and high-resolution microarray genotyping. The geographic origin and ancestral genealogy of each pedigree were researched in the medical literature and Swedish Parish records. Results: The proband of the Swedish family branch presented with early dysautonomia followed by progressive parkinsonism suggestive of multiple system atrophy. Molecular analysis identified a genomic duplication of <0.9 Mb encompassing α-synuclein and multimerin 1 (SNCA-MMRN1), flanked by long interspersed repeat sequences (LINE L1). Microsatellite variability within the genomic interval was identical to that previously described for a Swedish American family with an α-synuclein triplication. Subsequent genealogic investigation suggested that both kindreds are ancestrally related to the Lister family complex. Conclusion: Our findings extend clinical, genetic, and genealogical research on the Lister family complex. The genetic basis for familial parkinsonism is an SNCA-MMRN11 multiplication, but whereas SNCA-MMRN1 duplication in the Swedish proband (Branch J) leads to late-onset autonomic dysfunction and parkinsonism, SNCA-MMRN1 triplication in the Swedish American family (Branch I) leads to early-onset Parkinson disease and dementia.