Cited by 204Parkinson's Disease Mechanisms and TreatmentsDementia and Cognitive Impairment ResearchNeurological disorders and treatments

Diagnosis of Parkinson's disease on the basis of clinical and genetic classification: a population-based modelling study

Open access
Nalls, Mike A, McLean, Cory Y, Rick, Jacqueline, Eberly, Shirley, Hutten, Samantha J, Gwinn, Katrina, Sutherland, Margaret, Martinez, Maria +32 more·2015·The Lancet Neurology

Abstract

Background Accurate diagnosis and early detection of complex diseases, such as Parkinson's disease, has the potential to be of great benefit for researchers and clinical practice. We aimed to create a non-invasive, accurate classification model for the diagnosis of Parkinson's disease, which could serve as a basis for future disease prediction studies in longitudinal cohorts.Methods We developed a model for disease classification using data from the Parkinson's Progression Marker Initiative (PPMI) study for 367 patients with Parkinson's disease and phenotypically typical imaging data and 165 controls without neurological disease. Olfactory function, genetic risk, family history of Parkinson's disease, age, and gender were algorithmically selected by stepwise logistic regression as significant contributors to our classifying model. We then tested the model with data from 825 patients with Parkinson's disease and 261 controls from five independent cohorts with varying recruitment strategies and designs: the Parkinson's Disease Biomarkers Program (PDBP), the Parkinson's Associated Risk Study (PARS), 23andMe, the Longitudinal and Biomarker Study in PD (LABS-PD), and the Morris K Udall Parkinson's Disease Research Center of Excellence cohort (Penn-Udall). Additionally, we used our model to investigate patients who had imaging scans without evidence of dopaminergic deficit (SWEDD).Findings In the population from PPMI, our initial model correctly distinguished patients with Parkinson's disease from controls at an area under the curve (AUC) of 0·923 (95% CI 0·900-0·946) with high sensitivity (0·834, 95% CI 0·711-0·883) and specificity (0·903, 95% CI 0·824-0·946) at its optimum AUC threshold (0·655). All Hosmer-Lemeshow simulations suggested that when parsed into random subgroups, the subgroup data matched that of the overall cohort. External validation showed good classification of Parkinson's disease, with AUCs of 0·894 (95% CI 0·867-0·921) in the PDBP cohort, 0·998 (0·992-1·000) in PARS, 0·955 (no 95% CI available) in 23andMe, 0·929 (0·896-0·962) in LABS-PD, and 0·939 (0·891-0·986) in the Penn-Udall cohort. Four of 17 SWEDD participants who our model classified as having Parkinson's disease converted to Parkinson's disease within 1 year, whereas only one of 38 SWEDD participants who were not classified as having Parkinson's disease underwent conversion (test of proportions, p=0·003).Interpretation Our model provides a potential new approach to distinguish participants with Parkinson's disease from controls. If the model can also identify individuals with prodromal or preclinical Parkinson's disease in prospective cohorts, it could facilitate identification of biomarkers and interventions.Funding National Institute on Aging, National Institute of Neurological Disorders and Stroke, and the Michael J Fox Foundation.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1016/s1474-4422(15)00178-7

Cites

21 of 21 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Parkinson's disease is characterized by the accumulation of alpha-synuclein within neurons and the loss of neuronal cells.

    “Parkinson’s disease (PD) is a debilitating neurodegenerative disorder characterized by the accumulation of alpha-synuclein (αSyn) within neurons and the loss of neuronal cells1.”

    From Microglial inhibition alleviates alpha-synuclein propagation and neurodegeneration in Parkinson’s disease mouse model (2024) · cites this paper as [1]

    The Introduction describes Parkinson’s disease as a complex progressive disease and discusses indicators of neurodegeneration. Our copy does not state that Parkinson’s disease is characterized by intracellular alpha-synuclein accumulation or neuronal cell loss; searches for those features found no supporting passage. (LLM, conf=0.78)

    Experimental — accuracy not yet measured
  • There were four significant genetic correlations between Parkinson's disease and other traits (FDR-adjusted P < 0.05).

    “We found four significant genetic correlations (FDR-adjusted P < 0.05, Table S10) including positive correlations with intracranial volume and putamen volume (42), and negative correlations with current tobacco use and “academic qualifications: National Vocational Qualifications (NVQ) or Higher National Diploma (HND) or Higher National Certificate (HNC) or equivalent” (43).”
  • Parkinson's disease had a negative genetic correlation with academic qualifications: National Vocational Qualifications (NVQ) or Higher National Diploma (HND) or Higher National Certificate (HNC) or equivalent.

    “We found four significant genetic correlations (FDR-adjusted P < 0.05, Table S10) including positive correlations with intracranial volume and putamen volume (42), and negative correlations with current tobacco use and “academic qualifications: National Vocational Qualifications (NVQ) or Higher National Diploma (HND) or Higher National Certificate (HNC) or equivalent” (43).”
  • Parkinson's disease had a negative genetic correlation with current tobacco use.

    “We found four significant genetic correlations (FDR-adjusted P < 0.05, Table S10) including positive correlations with intracranial volume and putamen volume (42), and negative correlations with current tobacco use and “academic qualifications: National Vocational Qualifications (NVQ) or Higher National Diploma (HND) or Higher National Certificate (HNC) or equivalent” (43).”

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Authors
Nalls, M. A., McLean, C. Y., Rick, J., Eberly, S., Hutten, S. J., Gwinn, K., Sutherland, M., Martinez, M., Heutink, P., Williams, N. M., Hardy, J., Gasser, T., Brice, A., Price, T. R., Nicolas, A., Keller, M. F., Molony, C., Gibbs, J. R., Chen-Plotkin, A., Suh, E., Letson, C., Fiandaca, M. S., Mapstone, M., Federoff, H. J., Noyce, A. J., Morris, H., Van Deerlin, V. M., Weintraub, D., Zabetian, C., Hernandez, D. G., Lesage, S., Mullins, M., Conley, E. D., Northover, C. A. M., Frasier, M., Marek, K., Day-Williams, A. G., Stone, D. J., Ioannidis, J. P. A., & Singleton, A. B.
Affiliations
  • National Institutes of Health (US)
  • 23andMe (United States) (US)
  • University of Pennsylvania (US)
  • University of Rochester Medicine (US)
  • Michael J. Fox Foundation (US)
  • Université Toulouse III - Paul Sabatier (FR)
  • German Center for Neurodegenerative Diseases (DE)
  • Cardiff University (GB)
  • UCL Queen Square Institute of Neurology (GB)
  • Hertie Institute for Clinical Brain Research (DE)
  • Centre National de la Recherche Scientifique (FR)
  • Merck & Co., Inc., Rahway, NJ, USA (United States) (US)
  • Georgetown University Medical Center (US)
  • VA Puget Sound Health Care System (US)
  • Biogen (United States) (US)
  • Stanford Medicine (US)
Corresponding author
Singleton, Andrew B
Venue
The Lancet Neurology
Publisher
Elsevier BV
Published
2015-10
Volume
14
Issue
10
Pages
1002-1009
ISSN
1474-4422 (ISSN-L)
OpenAlex
W2098399146
Cited by
204
References
21
Citations by year
2026: 11 · 2025: 14 · 2024: 15 · 2023: 10 · 2022: 16 · 2021: 15 · 2020: 29 · 2019: 21 · 2018: 21 · 2017: 28 · 2016: 19 · 2015: 5
FWCI
17.16
Type
journal article
Language
en
Open access
Locations
  • The Lancet Neurology (publishedVersion)
  • PubMed (publishedVersion)
  • Europe PMC (PubMed Central) (acceptedVersion)
  • PubMed Central (acceptedVersion)
  • UCL Discovery (University College London) (submittedVersion)
  • eScholarship (California Digital Library) (submittedVersion)
  • ORCA Online Research @Cardiff (Cardiff University) (submittedVersion)
  • DZNE Pub (submittedVersion)
  • Queen Mary Research Online (Queen Mary University of London) (submittedVersion)
Funders
  • NINDS (U01NS082134, U01NS082157, U01NS082151, U01NS082137, U01NS082148, U01NS082133, grant P50NS053488 and P50 NS062684)
  • Parkinson's UK (Grants 8047)
  • Medical Research Council UK (G0700943, G1100643)
Topics
  • Health Sciences › Medicine › Neurology › Parkinson's Disease Mechanisms and Treatments
  • Health Sciences › Medicine › Psychiatry and Mental health › Dementia and Cognitive Impairment Research
  • Health Sciences › Medicine › Neurology › Neurological disorders and treatments
Keywords
Parkinson's disease, non-invasive diagnosis, olfactory function, genetic risk, family history (medicine), imaging biomarkers, dopaminergic deficit, Parkinson's Progression Markers Initiative, external validation, early detection, disease prediction, clinical classification, Parkinson's disease biomarker
MeSH terms
Aged, Female, Humans, Male, Middle Aged, Parkinson Disease, Models, Statistical, Cohort Studies, Disease Progression, Prodromal Symptoms

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review