Our work complements previous work on the effect of clock expression of Tau and Aβ42 on circadian rhythms and sleep disruption in flies including Aβ42 and Tau sleep less during the day and night, while expression of tandem Aβ42 and Tau caused behavioural arrhythmia and sleep fragmentation19–21,27,61,62, and extends this to show that clock expression of mnb also causes sleep loss. The gene discussed is CLOCK; the disease is cardiac arrhythmia.