DSCAML1 and early-onset autosomal dominant Alzheimer disease: Examples include low-density lipoprotein receptor-related protein 6 (LRP6), a co-receptor for Wnt signaling, which is down-regulated in Alzheimer’s disease and which appears critical for maintaining synaptic integrity (158); Down syndrome cell adhesion molecule-like 1 (Dscaml1), which appears essential for development of GABAergic neurons in the entorhinal cortex (159); and ZMIZ1, a transcription factor co-activator, for which mutant allele over-expression leads to pyramidal neuron morphology abnormalities (160).