GBA1 and Parkinson disease: However, given that clinical manifestation and pathological findings are almost identical in PD‐GBA1 and idiopathic PD patients, it is thought that, as in idiopathic PD, alpha‐synuclein accumulation, mitochondrial impairment, autophagic dysfunction, inflammation, and oxidative and endoplasmic reticulum stress may play an important role in both the development and progression of PD‐GBA1 (Schapira and Tolosa 2010).