GBA1 and Parkinsonism: <b>Methods:</b> We analyzed 1390 PD patients from the Parkinson's Progression Markers Initiative (PPMI) with genotypes available for seven PD-associated genes (<i>LRRK2</i>, <i>GBA1</i>, <i>SNCA</i>, <i>PRKN</i>, <i>PINK1</i>, <i>PARK7</i>, <i>VPS35</i>), including specific variant resolutions (<i>LRRK2 G2019S</i>, <i>R1441G/C/H</i>; <i>GBA1 N409S</i>, severe variants; <i>SNCA</i><i>A53T</i>), and <i>APOE</i> (ε2/ε3/ε4 alleles).