Many of the isoforms recognized by APPRIS as alternative are likely to have substantial changes to their structure and function. A total of 37 550 alternative splice variants (70.4% of the variants tagged as alternative) would lose important functional or structural information relative to the principal isoform. The conservative estimates from the APPRIS methods show that 15 087 variants (28.3%) would lose important functional residues, 31 169 alternative gene products (58.5%) would have damaged or lost Pfam functional domains and 26 955 alternative isoforms (50.6%) would lose a substantial part of their 3D structure.
