GBA1 and Parkinson disease: The number of first‐degree relatives (excluding children) with Parkinson's disease was higher in p.D140H + p.E326K carriers (5.6%, 21 of 376) compared with p.E326K carriers (2.9%, 29 of 1014); OR, 2.0; P = 0.022, suggestive of a dose effect for different GBA1 variants.