Figure 2. Inducible transgenic constructs rescue mice from Sandhoff disease.

(A) Hexb−/− mice that carry the Hex or SYN transgenic cassettes show an average survival of 373 or 404 days, respectively. This is a three-fold increase on Hexb−/− mice that do not carry a transgenic expression construct and only survive to an average of 127 days. Plots show data points overlaid with the mean ± SEM. (B) Motor performance of transgenic animals was assessed using the inverted screen test and performance measured by multiplying latency to fall (seconds) by number of hindlimb movements. Hexb−/− Sandhoff mice rapidly deteriorated after 14 weeks of age (green triangles). Hexb−/−Hex^Tg and Hexb−/−SYN^Tg mice showed motor performance comparable with Hexb+/− mice up until six months of age, by which point transgenic mice began progressive deterioration that culminated in humane endpoint at approximately one year of age. n = 6, 8, 11 and 9 mice for Hexb−/−Hex^Tg, Hexb−/−SYN^Tg, Hexb−/− and Hexb+/− respectively. Data points represent mean ± SEM.