SYT4 and early-onset autosomal dominant Alzheimer disease: Syt4 has been implicated in these diseases, and genome-wide association studies have found single nucleotide polymorphisms associated with Parkinson's disease (Chang et al., 2017) and Alzheimer's disease (Jansen et al., 2019); altered Syt4 expression has also been observed in an experimental model of ischemia (Yokota et al., 2001).