However, no accumulation of GlcCer or GlcSph was detected in PD brains with heterozygote GBA mutations (Gegg et al., 2015), or mouse models lacking one of the GBA alleles (GBA +/−; Farfel-Becker et al., 2014, Sardi et al., 2011). This evidence concerns the gene GBA1 and Parkinson disease.