However, imbalances in the tau isoform ratio are a defining feature of various tauopathies and several missense, silent and intronic mutations in the MAPT gene associated with FTDP affect splicing of exon 10, frequently leading to greater inclusion of exon 10 consistent with neuropathological findings describing deposits of exon 10+ (4R) tau isoforms7, 9, 31, 51. This evidence concerns the gene MAPT and tauopathy.