BACE2 isoforms present in human brain. Human brain cDNA samples were screened for BACE2 isoforms using conventional PCR amplification across the alternatively spliced regions of exons 7 and 8. (A) Four alternatively spliced BACE2 isoforms were detected among multiple individuals. (B) Direct sequencing of the resulting splice variants confirmed their identities as BACE2d7, BACE2d8 and BACE2d7/8. Deletion of BACE2 exon 7 results in an in-frame deletion of 50 amino acids whereas deletions of BACE2 exon 8 or exons 7 and 8 lead to a frameshift and premature truncation of the protein.