Rett syndrome: analysis of deaths in the British survey.

The mortality rate in Rett syndrome is 1.2% per annum, 48% of deaths occurring in debilitated people, 13% from natural causes, 13% with prior severe seizures and 26% sudden and unexpected. Respiratory dysrhythmias were usually present. Neuropathology confirmed reductions in cortical dendrites and in one case immaturity of cardiac conducting tissues.