“…It has been known for some time that while the characteristic lesions of CBD (tau-positive astrocytic plaques and thread-like lesions in both the white and grey matter) discriminates CBD from the other FTLD-tau subtypes, they do not discriminate sporadic CBD cases from those with MAPT mutations ( Dickson et al , 2002 ) and therefore recent clinical criteria exclude cases with a family history or MAPT mutation from a diagnosis of probable (although not possible) CBD ( Armstrong et al , 2013 ). It has also been long recognized that there is considerable clinical, pathological and genetic overlap between CBD and PSP ( Katsuse et al , 2003 ; Lang, 2003 ; Tan et al , 2005 ; Jung et al , 2012 ) with genome wide association studies showing that common polymorphisms in MAPT , MOBP and VEGFA increase the risk for both CBD and PSP ( Borroni et al , 2010 ; Kouri et al , 2014 , 2015 ). While familial forms of the CBD pathological subtype are recognized ( Dickson et al , 2002 ), familial forms of PSP occur but are considered rare (<10% of cases) ( de Yebenes et al , 1995 ; Rojo et al , 1999 ; Vanacore et al , 2001 ; Ros et al , 2005 ; Donker Kaat et al , 2009 ; Rohrer et al , 2011 ; Fujioka et al , 2015 ), possibly because of the more typical motor phenotype being identified with pathological PSP.…”