LAUSR

Description A glycoprotein is a possible biomarker of pathogenic progression for Parkinson’s disease The diagnosis of Parkinson’s disease (PD) relies on the presence of motor symptoms that occur when 50 to 70% of dopaminergic neurons in the substantia nigra degenerate. However, this happens after at least 20 years of the prodromal (premotor) phase. The spreading of α-synuclein (αSyn) aggregates, called fibrils, is pathologically associated with PD (1). However, the mechanisms leading to neurodegeneration continue to be debated. Alterations in the gene encoding αSyn are associated with increased risk of PD. Similarly, single-nucleotide polymorphisms (SNPs) that drive expression of glycoprotein nonmetastatic melanoma protein B (GPNMB) are associated with increased risk of PD (2, 3). On page 833 of this issue, Diaz-Ortiz et al. (4) report confirmation that SNPs increase GPNMB expression and confer PD risk. GPNMB was increased in the blood of PD patients and associated with disease severity, suggesting that GPNMB could be a biomarker of PD progression.