Thesefindings raised the question as to whether some CBS should be considered atypicalAD.28 Tau/Abeta ratio inCSF, as used in this study, may represent a useful way of detecting CBS-AD in vivo,although neuropathological confirmation is not yet forthcoming and the technique'ssensitivity for detecting CBS-AD at an early stage has yet to bedetermined.48 The gene discussed is MAPT; the disease is Alzheimer disease.