A schematic showing the structural annotation of different pseudogene biotypes. The schematic diagram illustrates the categorization of GENCODE pseudogenes on the basis of their origin. Processed pseudogenes are derived by a retrotransposition event and unprocessed pseudogenes by a gene duplication event in both cases, followed by the gain of a disabling mutation. Both processed and unprocessed pseudogenes can retain or gain transcriptional activity, which is reflected in the transcribed_processed and transcribed_unprocessed_pseudogene classification. Polymorphic pseudogenes contain a disabling mutation in the reference genome but are known to be coding in other individuals, while unitary pseudogenes have functional protein-coding orthologs in other species (we have used mouse as a reference) but contain a fixed disabling mutation in human.
