Akihide Kondo

Conflicts of Interest The authors declare that there are no conflicts of interest. A part of the cohort in this study includes patient data published in the paper by Akaike et al. (Human Pathology, 2015, 46:347-356). However, we analyzed the data using a different analysis approach and obtained novel findings specific to our cohort, which we are reporting this.

Correction to: Nature Medicine https://doi.org/10.1038/s41591-023-02358-9, published online 29 May 2023. In the version of the article initially published, in Extended Data Fig. 3c, the image in the SN row under MSA-C (1 Y) was incorrect and has now been amended in the HTML and PDF versions of the article.

Abstract Abnormal α-synuclein aggregation is a key pathological feature of a group of neurodegenerative diseases known as synucleinopathies, which include Parkinson’s disease (PD), dementia with Lewy bodies and multiple system atrophy (MSA). The pathogenic β-sheet seed conformation of α-synuclein is found in various tissues, suggesting potential as a biomarker, but few studies have been able to reliably detect these seeds in serum samples.