The annotation of has been concealed by its protein-coding pseudogene .

Mutations in cause Gaucher disease and are the most important genetic risk factor for Parkinson's disease. However, analysis of transcription at this locus is complicated by its highly homologous pseudogene, . We show that >50% of short RNA-sequencing reads mapping to also map to . Thus, we used long-read RNA sequencing in the human brain, which allowed us to accurately quantify expression from both and . We discovered significant differences in expression compared to short-read data and identify currently unannotated transcripts of both and . These included protein-coding transcripts from both genes that were translated in human brain, but without the known lysosomal function-yet accounting for almost a third of transcription. Analyzing brain-specific cell types using long-read and single-nucleus RNA sequencing revealed region-specific variations in transcript expression. Overall, these findings suggest nonlysosomal roles for and with implications for our understanding of the role of in health and disease.