GBA1 and Parkinson disease: Therefore, this study was designed to identify the genetic causes of EOPD by using a combination of multiplex ligation‐dependent probe amplification (MLPA) and next‐generation sequencing (NGS) for a panel of 20 PD‐associated genes: SNCA, PRKN, GBA1, PINK1, DJ‐1, LRRK2, ATP13A2, VPS35, UCHL1, PLA2G6, FBXO7, DNAJC6, SYNJ1, HTRA2, EIF4G1, DNAJC13, CHCHD2, VPS13C, GCH1, and MAPT.