Reduction in ChAT activity (Davies, 1976; Perry et al., 1977; Rossor et al., 1982; Wilcock et al., 1982), cholinergic receptor number (Nordberg and Winblad, 1986), AChE activity (Davies, 1976; Geula and Mesulam, 1995), and decrease in high affinity choline uptake have been observed in AD (Rylett et al., 1983; Pascual et al., 1991). The gene discussed is CHAT; the disease is Alzheimer disease.